McGraw-Hill Specialty Board Review Pediatrics, 2nd Edition

Chapter 6. GASTROENTEROLOGY

CASE 46: A 1-MONTH-OLD WITH JAUNDICE

A 1-month-old boy is brought to your office for a routine checkup. The baby was born at full term and his birthweight was 4.1 kg. His mother had routine prenatal care and no complications during the pregnancy. The child is exclusively breast-fed and was first noted to be jaundiced at 3 days of age. His bilirubin peaked on day of life 6 and then began to decrease. Mom reports he has “always been yellow.” She denies irritability, fever, vomiting, or diarrhea. She reports that the child eats well and has yellow seedy stools each time he feeds.

On physical examination, the child’s weight is 5 kg. He is in no apparent distress. He has jaundiced skin and icteric sclera. His cardiac and respiratory systems are unremarkable. His abdomen is nondistended with normal bowel sounds. His liver is palpable 2 cm below the right costal margin and his spleen tip is palpable. The remainder of his examination is unremarkable.

SELECT THE ONE BEST ANSWER

1. The first laboratory test indicated in the evaluation of this patient is

(A) conjugated bilirubin

(B) blood culture

(C) hepatic function test

(D) none; because of earlier bilirubin testing, no further testing is necessary

(E) complete blood count (CBC)

2. Below are results for this child’s laboratory evaluation

Hemoglobin

12.5 g/dL

Platelets

256,000/mm3

Albumin

3.8 g/dL

Alanine aminotransferase
(ALT)

70 IU/L

Aspartate aminotransferase
(AST)

65 IU/L

Gamma glutamyl transferase
(GGT)

458 IU/L

Alkaline phosphatase

606 IU/L

Conjugated bilirubin

4 mg/dL

Total bilirubin

7 mg/dL

Prothrombin time (PT)

13 seconds;
international 
normalized ratio (INR) 1.0

Which entity is least likely in the differential diagnosis?

(A) biliary atresia

(B) Alagille syndrome

(C) choledochal cyst

(D) congenitally acquired hepatitis B

(E) neonatal hepatitis

3. The additional immediate evaluation for this child should include

(A) ultrasound, α1-antitrypsin level, urine reducing substance, urine culture

(B) hepatitis B surface antigen, hepatitis C antibody, toxoplasmosis, rubella, cytomegalovirus, herpes simplex, ie the so-called TORCH titers

(C) serum amino acids and urine organic acids

(D) thyroid-stimulating hormone (TSH) and a sweat test

(E) all of the above

4. If this patient had an ultrasound that demonstrated a choledochal cyst, the next step in management is to

(A) call interventional radiology for drainage of the cyst

(B) do nothing; most cysts resolve spontaneously

(C) consult a surgeon because complete resection of cyst is necessary

(D) treat conservatively with ursodiol

(E) monitor yearly hepatic function panels

5. If this child had a history of vomiting and no red reflex on ophthalmologic examination, the first thing you would do is

(A) check amino acids levels

(B) check an ammonia (NH3) level

(C) have mother stop breast-feeding the child

(D) consult ophthalmology

(E) stop giving the infant protein

6. If the child from question 5 has a fever and looks ill, then this child is at significant risk for

(A) liver failure

(B) Escherichia coli sepsis

(C) group B streptococcal sepsis

(D) Listeria infection

(E) all of the above

7. If the child has laboratory results as outlined in question 2 and a sibling had a similar presentation in infancy, this child’s possible diagnoses include

(A) α1-antitrypsin deficiency

(B) biliary atresia

(C) neonatal hepatitis

(D) choledochal cyst

(E) none of the above

8. If this child had a systolic ejection murmur with a fixed split second heart sound, what additional test(s) would you order?

(A) chest radiograph

(B) echocardiogram

(C) ophthalmology examination

(D) A, B, C

(E) A, B

9. If this child’s weight was 3.9 kg at presentation, what further evaluation is indicated?

(A) sweat test

(B) thyroid function

(C) serum glucose level

(D) calorie count

(E) all of the above

10. If this child had been treated with amoxicillin suspension for the past week for otitis media, what additional evaluation is indicated?

(A) serum glucose, lactic acid, uric acid, magnesium, and phosphate levels

(B) serum fructoaldolase level

(C) PT, NHlevel

(D) A and C

(E) ultrasound, α1-antitrypsin level, urine reducing substance, urine culture

11. The patient from question 2 had an additional workup, with the following results:

Urine culture: no growth in 48 hours

Urine reducing substances: negative

α1-antitrypsin level: 198

Ultrasound: normal liver echogenicity, no biliary dilation and no masses

This patient’s diagnosis is likely to be

(A) neonatal hepatitis

(B) biliary atresia

(C) congenitally acquired hepatitis B

(D) TORCH infection

(E) undetermined; there is not enough information to make a diagnosis

12. Which test is best used to distinguish biliary atresia from neonatal hepatitis?

(A) hepatobiliary scintigraphy

(B) liver biopsy

(C) endoscopic retrograde cholangiopancreatography (ERCP)

(D) abdominal computed tomography (CT)

(E) gallbladder ultrasound

13. It is vital to a patient’s long-term prognosis for the diagnosis of biliary atresia to be made before

(A) 1 month of age

(B) 2 months of age

(C) 6 months of age

(D) 12 months of age

(E) the age the diagnosis is made is not important

14. If this patient is diagnosed with biliary atresia, the next step is

(A) repeat liver biopsy in 3 months

(B) biliary stent

(C) cholecystostomy

(D) Kasai procedure

(E) liver transplantation

15. If this patient is diagnosed with neonatal hepatitis, the next step is

(A) start fat-soluble vitamins

(B) start ganciclovir

(C) start ursodiol

(D) A and C

(E) B and C

16. Standard medical treatment for cholestasis includes

(A) ursodiol treatment

(B) vitamin A, D, E, and K supplementation, nutritional support, ursodiol treatment, and treatment for pruritus

(C) vitamin K supplementation and nutritional support

(D) A and C

(E) none of the above

17. If a patient with cholestatic liver disease was 4 days old instead of 4 weeks old, the likely diagnosis would be

(A) biliary atresia

(B) viral infection

(C) bacterial infection

(D) ornithine transcarbamylase deficiency

(E) B and C

18. Suppose the patient in question 17 had a platelet count of 23,000, a PT of 20 seconds (INR 4), low fibrinogen, and an elevated d-dimer concentration. Furthermore, the patient has a palpable spleen and no palpable liver. Further evaluation would include

(A) bacterial cultures, viral cultures, abdominal magnetic resonance imaging (MRI)

(B) bacterial cultures, viral cultures, liver biopsy

(C) bacterial cultures, viral cultures, bone marrow biopsy

(D) viral cultures, abdominal MRI, liver biopsy

(E) blood and urine cultures

ANSWERS

1. (A) The most important thing to determine is whether this child has conjugated or unconjugated hyperbilirubinemia. All other diagnostic and therapeutic steps are based on this distinction.

2. (D) Although the term LFTs (liver function tests) is commonly used, its meaning is often unclear. There are 3 distinct groups of “liver labs.” Serum transaminase (ALT and AST) elevation indicates hepatocellular damage or death (many causes). GGT and alkaline phosphatase are enzymes found in high concentration in the biliary system, and elevations indicate biliary tree disease. Bilirubin, PT, albumin, and NHare true LFTs and indicators of liver function. These laboratory values indicate cholestatic liver disease secondary to biliary disease with normal liver function.

Congenital hepatitis B causes a carrier state in most infants, and they have normal “liver labs.” In a small percentage of infants, it can cause fulminant hepatic failure. Neither of those scenarios is consistent with the laboratory values.

Each of the other entities can present with elevated GGT and alkaline phosphatase and no elevation in ALT and AST.

3. (A) The differential diagnosis of cholestatic liver disease in an otherwise healthy 1-month-old includes

Cholestatic disorders

Biliary atresia

Idiopathic neonatal hepatitis

Choledochal cyst

Alagille syndrome

Persistent familial intrahepatic cholestasis (PFIC)

Metabolic disorders

α1-antitrypsin deficiency

Galactosemia

Disorders of bile acid synthesis

Other

Urinary tract infection

4. (C) Because there is an increased risk of cholangiocarcinoma in cyst remnants, choledochal cysts require complete surgical removal (see Figure 46-1).

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FIGURE 46-1. Classification of choledochal cysts. Type I, fusiform or cystic dilations of the extrahepatic biliary tree, is the most common type, making up >50% of the choledochal cysts. Type II, saccular diverticulum of an extrahepatic bile duct. Rare, <5% of choledochal cysts. Type III, bile duct dilatation within the duodenal wall (choledochoceles), makes up about 5% of choledochal cysts. Type IVa and IVb, multiple cysts, make up 5-10% of choledochal cysts. Type IVa affects both extrahepatic, and intrahepatic bile ducts while Type IVb cysts affect the extrahepatic bile ducts only. Type V, intrahepatic biliary cysts, is very rare and makes up 1% of choledochal cysts. (Reproduced, with permission, from Brunicardi FC, Andersen DK, Billiar TR, et al. Schwartz’s Principles of Surgery, 9th ed. New York: McGraw-Hill; 2010: Fig. 32-22.)


5. (C) Vomiting and cataracts in a cholestatic 1-month-old is galactosemia until proven otherwise. The treatment is elimination of exposure to galactose (in the lactose of breast milk and cow’s milk formula).

6. (B) In patients with galactosemia, continued exposure to galactose causes inhibition of leukocyte bactericidal activity. This puts them at increased risk for E coli sepsis.

7. (A) The diagnosis of α1-antitrypsin deficiency is possible because this is inherited in an autosomal codominant fashion. There are 3 predominant alleles: M, S, and Z. The M allele produces normal levels of α1-antitrypsin. The S allele gives moderately low levels, and Z is associated with very low levels. The patient with ZZ is likely to have α1-antitrypsin deficiency liver disease. Patients with SZ are at an increased risk for developing lung disease. Patients with at least 1 M allele are unlikely to have clinical disease.

8. (D) The murmur described is consistent with pulmonic stenosis. In infants with pulmonic stenosis and cholestatic liver disease, your index of suspicion for Alagille syndrome must be high. Other features include characteristic facies (this can be difficult to distinguish in an infant), pulmonic stenosis (echocardiogram), butterfly vertebrae (chest x-ray), and posterior embryotoxon (ophthalmologic examination).

9. (E) Clearly, this child has failure to thrive (FTT) and cholestasis. The differential diagnosis includes cystic fibrosis and hypopituitarism. Even in the face of pathology (conjugated hyperbilirubinemia) one must consider malnutrition contributing to the FTT. All of the tests listed would be indicated (see Figure 46-2).

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FIGURE 46-2. Failure to thrive. This infant has not been able to maintain a normal growth pattern and appears cachectic. (Reproduced, with permission, from Knoop KJ, Stack LB, Storrow AS, et al. Atlas of Emergency Medicine, 3rd ed. New York: McGraw-Hill; 2010:446. Photo contributor: Kevin J. Knoop, MD, MS.)


10. (D) Most pediatric drug suspensions contain sucrose (a disaccharide that contains glucose and fructose) and can induce symptoms in patients with hereditary fructose intolerance. Fructoaldolase levels are measured in liver tissue, not blood. The metabolic consequences of the disease are secondary to accumulation of fructose-1-phosphate (see Figure 46-3). In addition to the metabolic consequences, the child may develop hepatic failure. Therefore, each child should have a prothrombin time test and an NHlevel measured.

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FIGURE 46-3. Fructose metabolism.


11. (E) It is impossible to distinguish between biliary atresia and neonatal hepatitis based on these laboratory results.

12. (B) Hepatobiliary scintigraphy can (under the right conditions) distinguish between biliary atresia and neonatal hepatitis. In neonatal hepatitis, dye is excreted from the liver into the gut; in biliary atresia it is not. The test, however, has significant limitations. It is most reliable when the patient has been pretreated with phenobarbital for 5 days to induce biliary flow. Even with pretreatment, the liver often does not excrete bile in the presence of significant cholestasis. If the serum bilirubin level is more than 10 mg/dL, failure to excrete is almost universal and this test is unreliable and unhelpful. Because of the issues of patient size, ERCP is very difficult to perform in a 1-month-old. Very few gastroenterologists are skilled enough to do a successful ERCP at this age. If there is no gallbladder visualized on an ultrasound, that finding is consistent with biliary atresia but not diagnostic. Liver biopsy will best distinguish between these 2 diseases and provide an accurate and expeditious diagnosis. Percutaneous liver biopsy can safely be performed by many gastroenterologists and radiologists.

13. (B) See below.

14. (D) The procedure to correct biliary atresia is known as a Kasai procedure. In the Kasai procedure, an intrahepatic bile duct is connected directly to a loop of bowel to provide bile drainage and delay hepatic damage. The likelihood of success of the Kasai decreases dramatically when performed after 8 weeks of age. Because of this, making a definitive diagnosis and instituting therapy quickly is vital. Without a successful Kasai procedure, the patient will be committed to an early liver transplant. Because of the difficulty in obtaining ideally size-matched organs in a very young patient, this is not ideal.

15. (D) Neonatal hepatitis resolves in most patients. This hepatitis is not infectious, and antiviral medications are not indicated. Ten percent of patients develop end-stage liver disease and require a liver transplant. Any pediatric patient with cholestasis requires medical support for the cholestasis.

16. (B) Patients with cholestasis have a decreased ability to absorb fats (nutritional support) and fatsoluble vitamins (A, D, E, and K). Ursodiol protects the liver during cholestatic injury. Pruritus can also develop in cholestatic patients and can be treated with antihistamines, rifampin, or naltrexone.

17. (E) In newborns, the likely diagnosis for cholestatic liver disease is an infectious etiology. There are 2 types of biliary atresia. The most common was detailed in previous discussions, but there is also a rare neonatal form that is more likely associated with other congenital anomalies and can present in the first week of life. Ornithine transcarbamylase (OTC) deficiency is a urea cycle defect and would present with hyperammonemia and alteration in mental status.

18. (A) The laboratory data reveal a child with liver failure and disseminated intravascular coagulopathy (DIC). Bacterial infections can cause DIC and should be considered. Viral infections can cause hepatosplenomegaly and liver failure. With neonatal hemochromatosis infants are born with cirrhosis (small liver and splenomegaly) and liver failure. The diagnosis is made by demonstration of iron deposits in the pancreas on MRI. Liver biopsy in this child would be extremely dangerous and should be avoided if possible.


SUGGESTED READING

Bezzerra JA, Balistreri W. Cholestatic syndromes in infancy and childhood. Semin Gastrointest Dis. 2001;12(2):54-65.

McKiernan PJ. Neonatal cholestasis. Semin Neonatol. 2002;7(2):153-165.

CASE 47: AN 11-YEAR-OLD WITH CRAMPING ABDOMINAL PAIN

An 11-year-old girl is brought to your office with a complaint of periumbilical abdominal pain for 5 weeks. The pain is increased when the patient eats and relieved by stooling. The pain has awakened her from sleep several times. Ranitidine did not improve her symptoms. She denies melena or weight loss, but she has seen blood in her stool.

On physical examination she is a tired-appearing young lady whose weight is 34 kg (25%) and her height is 134 cm (10-25%). She has nonicteric sclera and a moist oropharynx. Her abdomen is nondistended with positive bowel sounds. There is no hepatosplenomegaly or masses. There is diffuse suprapubic tenderness. Rectal examination demonstrates normal sphincter tone and heme-positive stool.

SELECT THE ONE BEST ANSWER

1. Possible diagnoses for this child include

(A) inflammatory bowel disease

(B) infectious colitis

(C) irritable bowel syndrome

(D) peptic ulcer disease

(E) all of the above

2. Stool studies that are ordered should include

(A) search for fecal-reducing substances

(B) a bacterial culture

(C) a stool fungal culture

(D) ova and parasite examination

(E) none of the tests are likely to be useful

3. Likely stool pathogens include

(A) Campylobacter jejuni

(B) Yersinia enterocolitica

(C) E coli O157:H7

(D) Clostridium difficile

(E) all of the above

4. If the child’s CBC demonstrated a platelet count of 50,000, the next laboratory study(ies) you should order is/are

(A) erythrocyte sedimentation rate

(B) hepatic function panel

(C) serum creatinine

(D) PT

(E) all of the above

5. If the stool cultures were negative, the patient’s weight was 23 kg (<5th percentile), and the height was 123 cm (<5th percentile), your next step would be to check

(A) CBC, sedimentation rate, and C-reactive protein

(B) CBC, PT, bleeding time

(C) CBC, differential, and platelet count

(D) viral stool cultures

(E) antigliadin immunoglobulin (Ig)G antibodies

6. Below are the laboratory values for the patient in question 5

Hemoglobin

8.5 g/dL

Platelets

550,000/mm3

Mean corpuscular

75 fL

volume (MCV)

 

Sedimentation rate

58 mm/s

Albumin

2.8 g/dL

Gamma-glutamyl

300 IU/L

transpeptidase (GGTP)

 

Alkaline phosphatase

550 IU/L

The first radiology study you should order is

(A) abdominal radiograph

(B) barium enema

(C) upper gastrointestinal (GI) series with small bowel follow-through

(D) upper GI series without small bowel followthrough

(E) abdominal ultrasound

7. The findings you might expect on the study ordered in question 6 include

(A) bowel wall thickening in the ileum

(B) strictures in the jejunum

(C) fistulas

(D) delayed transit to the colon

(E) all of the above

8. What additional symptoms might your patient have suffered?

(A) early satiety

(B) right upper quadrant (RUQ) pain

(C) perianal abscess

(D) skin rash

(E) A and C

9. What nutritional therapies can be employed to treat this child?

(A) high-residue diet

(B) high-protein diet

(C) diet of elemental formula

(D) gluten-free diet

(E) none of the above

10. The child in the original vignette undergoes a colonoscopy that demonstrates pancolitis with erythema, edema, and granularity. The patient’s diagnosis could be

(A) ulcerative colitis

(B) Crohn disease

(C) pseudomembranous colitis

(D) A and B

(E) A, B, or C

11. The patient with pancolitis has a perinuclear antineutrophil cytoplasmic antibody (pANCA). Her diagnosis is

(A) ulcerative colitis

(B) Crohn disease

(C) autoimmune colitis

(D) A and B

(E) A, B, and C

12. First-line treatment of this moderately severe case of inflammatory bowel disease includes

(A) aminosalicylate

(B) steroids

(C) A and B

(D) no medications are needed because 20-30% of patients have a spontaneous remission

(E) Remicade

13. The patient in question 11 begins treatment and returns with severe abdominal pain, fever, and continued colitis. Evaluation should begin with

(A) abdominal ultrasound

(B) abdominal CT

(C) repeat colonoscopy

(D) barium enema

(E) observation

14. The risk of the patient from question 11 developing colon cancer in her life is

(A) higher than in the general population, and screening should begin after 10 years of active disease

(B) so high that prophylactic colectomy is recommended after 10 years of active disease

(C) the same as the general population. Medications to treat the disease have improved in the last decade so there is no longer any increased risk

(D) only high in those patients who have liver disease in addition to bowel disease

(E) about 20%

15. Based on the laboratory values in question 6, the liver disease in a patient with ulcerative colitis most likely is

(A) autoimmune hepatitis

(B) sclerosing cholangitis

(C) gallstones

(D) cholangiocarcinoma

(E) primary biliary cirrhosis

16. If a child has abdominal pain throughout the day that also wakes the patient at night, heme-positive stool, a physical examination with no abdominal tenderness, and a fissure noted on the rectal examination, your next step would be

(A) screening studies including a urinalysis, CBC, erythrocyte sedimentation rate

(B) reassurance and treatment for the fissure

(C) colonoscopy to ensure there is no additional pathology

(D) stool cultures

(E) blood for pANCA

17. The laboratory studies for the patient in question 16 are listed below:

Hemoglobin

13.5 g/dL

Platelets

240,000/mm3

MCV

86 fL

Sedimentation rate

9 mm/s

Albumin

3.9 g/dL

GGTP

30 IU/L

Alkaline phosphatase

250 IU/L

Other symptoms that may occur in this patient are

(A) epigastric pain and nausea

(B) constipation

(C) right lower quadrant pain

(D) diarrhea

(E) all of the above

18. Initial treatment for this disorder includes

(A) dietary change and reassurance

(B) medications

(C) further radiology or endoscopic testing

(D) referral to a gastroenterologist

(E) all of the above

ANSWERS

1. (E) This vignette describes symptoms that may reflect any of the listed diagnoses. Although hemepositive stools are less likely in irritable bowel syndrome compared with patients with inflammatory bowel syndrome, up to 35% of patients with irritable bowel syndrome report rectal bleeding. In this scenario, the red flags include pain in the middle of the night, blood in the stool, and the findings on physical examination.

2. (A) Without a history of antibiotic exposure, C difficile is an unlikely pathogen. The chronicity of the course makes bacterial enteritis unlikely. Giardia does not usually present with blood in the stool. Stool fungal cultures are of no value.

3. (E) Any of the pathogens listed can cause acute gastroenteritis with bloody stool, although none are particularly likely in this case. A possible exception is E coli O157. You would expect a history of antibiotic exposure with C difficile, but communityacquired cases without such exposure do occur.

4. (C) The most dangerous complication of an acute gastroenteritis with bloody stool is hemolytic uremic syndrome associated with E coli O157:H7. The laboratory findings of hemolytic uremic syndrome may present before the culture for E coli is positive. Those findings include renal insufficiency, hemolysis, thrombocytopenia, and, in severe cases, cerebral edema.

5. (A) The height and weight given are far below the fifth percentile for age. With the symptoms described you must be concerned that the patient has Crohn disease. Looking for signs of inflammation, anemia, and protein-losing enteropathy are the appropriate next steps. Although this patient could have celiac disease, detection of antigliadin IgG antibody is not the test of choice for celiac disease.

6. (C) A patient with iron deficiency anemia (low hemoglobin and low MCV), protein-losing enteropathy (low albumin), and increased inflammatory marker levels is likely to have Crohn disease. The best radiologic test would be an upper GI series with small bowel follow-through. Abdominal CT can also demonstrate small bowel disease

7. (E) The radiologic findings in a patient with Crohn disease is evidence of small bowel disease like strictures, bowel wall thickening, and fistulae. Transit through the GI tract may be delayed.

8. (E) In Crohn disease there is likely to be upper GI involvement (early satiety) and perianal disease (perianal abscess). Although there are some patients who have liver disease (RUQ pain), it is more likely to occur in a patient with ulcerative colitis. Skin rash is not a common feature of Crohn disease.

9. (C) Elemental formula is known to promote remission in patients with Crohn disease. The difficulty with this treatment is that the formulas have poor palatability and often require a nasogastric tube for infusion. Other recommendations include a lowresidue diet in patients with colitis.

10. (D) Crohn colitis and ulcerative colitis can look exactly the same on colonoscopy. Granulomas must be present on histology to make the diagnosis of Crohn’s. Serology can also assist in making the distinction. Pseudomembranous colitis is associated with C difficile infection. In pseudomembranous colitis there is a membrane or coating adherent to the mucosa that helps distinguish this entity from Crohn and ulcerative colitis.

11. (A) pANCA antibodies are specifically associated with ulcerative colitis.

12. (C) In a moderately severe case of inflammatory bowel disease (pancolitis), both steroids and aminosalicylates should be prescribed. Infliximab should be reserved for cases refractory to the above treatment.

13. (B) The most dangerous complication for a patient with ulcerative colitis is toxic megacolon. Risk factors for megacolon include drugs that interfere with intestinal motility, narcotics, antidiarrheal agents, and recent instrumentation. The megacolon can be seen on abdominal radiograph, but abdominal CT is a more sensitive and specific test. Treatment with bowel rest and antibiotics should be initiated when the diagnosis is suspected. Patients who do not respond to this conservative treatment may require colectomy.

14. (A) The risk for developing colon cancer depends on the extent of the colitis (pancolitis >left-sided colitis >proctitis) and the length of time it has been clinically apparent. The risk increases after 10 years. Patients with Crohn colitis are equally at risk for developing colon cancer.

15. (B) The most commonly associated liver disease in a patient with ulcerative colitis is sclerosing cholangitis (see Figure 47-1). The disease affects the biliary system. Therefore you would expect increased GGTP and alkaline phosphatase concentrations. Autoimmune hepatitis affects the hepatocytes, thereby causing an increased ALT and AST level. Gallstones are not associated with ulcerative colitis. Cholangiocarcinoma is a complication of longstanding sclerosing cholangitis, not an initial presentation of liver disease in an 11-year-old. Primary biliary cirrhosis is an adult liver disease.

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FIGURE 47-1. Sclerosing cholangitis. Endoscopic retrograde cholangiopancreatogram demonstrating diffusely narrowed intrahepatic bile ducts and one beaded area. (Reproduced, with permission, from Greenberger NJ, Blumberg RS, Burakoff R. Current Diagnosis & Treatment: Gastroenterology, Hepatology & Endoscopy. New York: McGraw-Hill, 2009: Fig. 52-1.)


16. (A) Although the patient has a normal abdominal examination, the presence of perianal disease and pain severe enough to be awakened is enough to order screening laboratory tests looking for inflammatory markers.

17. (E) The laboratory values in the table are all normal. It is unlikely for a patient with Crohn colitis or ulcerative colitis to have a normal hemoglobin, MCV, albumin, and erythrocyte sedimentation rate. Your conclusion is that this patient had irritable bowel syndrome, a variant of recurrent abdominal pain. About 10-15% of 4 to 16-year-old children have recurrent abdominal pain. The symptoms can include nonacid dyspepsia (epigastric pain and nausea), constipation, diarrhea, and migrating abdominal pain.

18. (A) Conservative therapy with dietary changes, particularly increasing dietary fiber and limiting lactose and high fructose corn syrup, is the first-line approach. In addition, reassurance about the benign nature of recurrent abdominal pain is crucial. Recognizing that the patient is in pain is important. You want to avoid overtesting, thereby contributing to the patient’s worry about the condition. Surgery is never necessary for irritable bowel syndrome.


SUGGESTED READING

Hyams JS. Crohn’s disease in children. Pediatr Clin North Am. 1996;43:255-277.

Kirschner BS. Ulcerative colitis. Pediatr Clin North Am. 1996;43:235-254.

Kohli R, Li BU. Differential diagnosis of recurrent abdominal pain: new considerations. Pediatr Ann. 2004;33:113-122.

CASE 48: A 4-YEAR-OLD BOY WITH RECTAL BLEEDING

A 4-year-old boy is brought to your clinic by his mother with a complaint of having 2 large maroon-colored stools on the morning of the visit. The mother is unsure whether the stools were accompanied by abdominal pain. She does report that the child seems less active than usual.

On examination, this is a quiet child with a heart rate (HR) of 165 and a respiratory rate (RR) of 40. He has nonicteric sclera and dry mucous membranes. His abdomen is nondistended with decreased bowel sounds and nontender without palpable masses. The remainder of the examination is unremarkable.

SELECT THE ONE BEST ANSWER

1. Your first step is

(A) reassure the parent because this is likely a fissure

(B) transfer to an emergency department for stabilization and evaluation

(C) admit to the hospital, collect stool cultures, and monitor closely

(D) send home to collect stool cultures before further workup

(E) order a CBC

2. The initial management should include

(A) gastric lavage

(B) fluid resuscitation

(C) abdominal ultrasound

(D) Meckel scan

(E) all of the above

3. The most likely diagnosis in this child is

(A) juvenile polyp

(B) Meckel diverticulum

(C) inflammatory bowel disease

(D) intussusception

(E) peptic ulcer

4. The diagnostic procedure required is

(A) barium enema

(B) abdominal ultrasound

(C) technetium-99m pertechnetate (Meckel) scan

(D) colonoscopy

(E) tagged red cell study

5. Had the mother described cramping abdominal pain before these “currant jelly” stools, the likely diagnosis would be

(A) Meckel diverticulum

(B) juvenile polyp

(C) intussusception

(D) infectious colitis

(E) inflammatory bowel disease

6. The treatment of choice for the patient in question 5 is

(A) contrast enema

(B) antibiotics to treat infectious colitis

(C) colonoscopy and removal of polyp

(D) exploratory laparotomy

(E) referral to a gastroenterologist

7. The mother asks what the chance is that the problem in question 5 will recur. Your answer is

(A) 2-5% no matter how treatment is rendered

(B) 10% no matter how treatment is rendered

(C) 20% no matter how treatment is rendered

(D) 50% no matter how treatment is rendered

(E) that it depends on the treatment rendered

8. Had the child passed bright red blood per rectum, had a HR of 98 and a RR of 24, and had a normal physical examination, your first step would be to

(A) reassure the parent because this is likely a fissure

(B) send the child home to collect stool cultures before further workup

(C) transfer the child to an emergency department for stabilization

(D) admit the child to the hospital, collect stool cultures, and monitor closely

(E) schedule emergent endoscopy

9. If the child has a single juvenile polyp, what is the possibility that this condition is a precursor to cancer?

(A) 50%

(B) less than 10%

(C) less than 1%

(D) there is not enough known about this entity to make a prediction

(E) the risk depends on whether there is a family history of colon cancer

10. Had the child in question 8 had dark, pigmented lips, his diagnosis would likely be

(A) Peutz-Jeghers syndrome

(B) Gardner syndrome

(C) Turcot syndrome

(D) multiple juvenile polyps

(E) familial adenomatous polyposis

11. A 15-year old presented with rectal bleeding and had a family history of colon cancer in multiple family members in their 30s. It is known that those family members had mutations in the APC gene. The diagnosis could be all of the following except (A) Peutz-Jeghers syndrome

(B) Gardner syndrome

(C) Turcot syndrome

(D) attenuated adenomatous polyposis coli (AAPC)

(E) familial adenomatous polyposis

12. If a 4-year-old had come in vomiting a large amount of bright red blood and tachycardic, your first step would be to

(A) send the patient for CBC

(B) send the child home to start Hblocker therapy

(C) refer the child to a gastroenterologist

(D) refer to the emergency department for stabilization and evaluation

(E) admit the child to the hospital for intravenous (IV) Hblocker therapy and a GI consult

13. The management of the patient in question 12 should include

(A) fluid resuscitation

(B) gastric lavage

(C) PT, hepatic function panel

(D) type and cross

(E) all of the above

14. The most likely diagnosis of the patient in question 12 is

(A) peptic ulcer/gastritis

(B) swallowed blood from epistaxis

(C) gastroesophageal reflux disease (GERD)

(D) Helicobacter pylori infection

(E) variceal bleed

15. Had the vomiting of blood occurred after multiple episodes of vomiting, then the most likely diagnosis would be

(A) viral gastritis

(B) malrotation

(C) Mallory-Weiss lesion

(D) arteriovenous malformation rupture

(E) esophageal varices

16. If the patient in question 12 was a 15-year-old from a lower socioeconomic background, then the most likely diagnosis would be

(A) peptic ulcer/gastritis

(B) herpetic esophagitis

(C) GERD

(D) H pylori infection

(E) esophageal varices

17. In regard to H pylori infection, the most appropriate test and treatment plan is

(A) serum antibodies and therapy with a proton pump inhibitor, clarithromycin, and amoxicillin or metronidazole

(B) stool antigen and therapy with a proton pump inhibitor, amoxicillin, and clarithromycin or metronidazole

(C) urea breath test and therapy with a proton pump inhibitor, clarithromycin, and amoxicillin or metronidazole

(D) endoscopy and therapy with a proton pump inhibitor, clarithromycin, and amoxicillin or metronidazole

(E) there is no gold standard, and any of the preceding choices is acceptable

18. If on physical examination the patient from question 12 had a small firm liver and spleen with ascites, the treatment would be

(A) transfer to the emergency department for stabilization

(B) correction of coagulopathy and the low platelet count

(C) somatostatin infusion

(D) endoscopic banding

(E) all of the above

ANSWERS

1. (B) Patients with evidence of hemodynamic compromise (HR 165 in a 4-year-old) must be stabilized before any workup.

2. (B) Fluid resuscitation should be the first step. Gastric lavage is not necessary. The description of the bleeding is from the lower GI tract. Although a vigorous upper GI bleed could cause passage of red blood per rectum, it is likely that the patient would be more unstable than the vignette describes. It is unlikely that an abdominal ultrasound would reveal the source of this bleeding. A Meckel scan could reveal the source of bleeding but should not be done until the patient is stable.

3. (B) The description of the bleeding could correspond to any of the entities listed. It is the remainder of the history and physical examination that reveals the answer. Meckel diverticulum causes significant bleeding in this age group. It is often painless (see Figure 48-1). A juvenile polyp does not cause significant blood loss and is not associated with hemodynamic instability. Intussusception is usually associated with cramping abdominal pain before bloody stool. A small percentage of children with intussusception present with extreme lethargy, pallor, and heme-positive stools. Infectious colitis causing this amount of bleeding would be associated with cramping abdominal pain and diarrhea.

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FIGURE 48-1. Meckel’s diverticulum. This intraoperative photograph shows Meckel’s diverticulum in ileum that has been eviscerated. (Reproduced, with permission, from Brunicardi FC, Andersen DK, Billiar TR, et al. Schwartz’s Principles of Surgery, 9th ed. New York: McGraw-Hill; 2010: Fig. 28-23.)


4. (C)

5. (C) See explanation for answer 3.

6. (A)

7. (E) If the intussusception is reduced surgically, the rate of recurrence is 2-5%. If the intussusception is reduced with a contrast enema, the chance of recurrence is 10% (see Figure 48-2).

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FIGURE 48-2. Intussusception. This is the prolapse of one segment of intestine into an adjoining segment. A. The four types of intussusception: The enfolding of the lumen is in the direction of fecal flow, as shown by the arrows. In the intracolic type, the stippling indicates a neoplasm that is usually the cause of the telescoping. B. Locations: The usual sites of palpable masses are shown as sausage-shaped outlines; these are usually in the colon. (Reproduced, with permission, from LeBlond RF, DeGowin RL, Brown DD. DeGowin’s Diagnostic Examination, 9th ed. New York: McGraw-Hill; 2009: Fig. 9-33.)


8. (B) Painless bright blood per rectum in this age group is likely because of a juvenile polyp. Most present between the ages of 2 and 10 years. They are unlikely to cause significant blood loss or other serious symptoms.

9. (C) There is no increased chance of malignancy associated with a solitary juvenile polyp. The risk is higher in patients who have 3 or more polyps. The risk is not related to family history.

10. (A) Several syndromes are associated with multiple polyps throughout the colon. Familial adenomatous polyposis coli (FAP) is an autosomal dominant condition characterized by large numbers of adenomatous (premalignant) lesions throughout the colon. The cause is a mutation in the tumor suppressor gene APC. These patients are at risk for colon cancer in the third decade of life. Definitive treatment is prophylactic colectomy. Mutations in the APC gene are responsible for Gardner syndrome (multiple colorectal polyps, osteomas, lipomas, fibromas epidermoid cysts, and dermoid tumors). APC mutations are responsible for some cases of Turcot syndrome (primary brain tumor and multiple colonic polyps). Peutz-Jeghers syndrome is a distinct disease caused by a rare autosomal dominant mutation characterized by mucosal pigmentation of the lips and gums and hamartomas throughout the GI tract. Symptoms include GI bleeding and cramping, abdominal pain, and obstruction because of intussusception. Cancer develops in 50% of patients. Colorectal, breast, and gynecologic tumors occur most frequently (see Figure 48-3).

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FIGURE 48-3. Peutz-Jeghers syndrome. A. Lentigines, which are dark brown to gray-blue, appear on the lips, around the mouth, and on the fingers. Lip macules may, over time, disappear. B. Macules of the buccal mucosa are blue to blue-black and are pathognomonic; unlike lip lesions, these do not tend to disappear with time. (Reproduced, with permission, from Wolff K, Goldsmith LA, Katz SI, et al. Fitzpatrick’s Dermatology in General Medicine, 7th ed. New York: McGraw-Hill; 2008: Fig. 73-18A, B.)


11. (A) See above.

12. (D) Same explanation as for question 1.

13. (E) Of course, the first step is to fluid-resuscitate the child. In this child there is an upper GI bleed with hemodynamic instability. This is very unusual for a 4-year-old. The nasogastric lavage will allow you to determine whether there is continued bleeding. There is a possibility that this could be a variceal bleed, so it is important to check liver numbers and function (especially PT).

14. (A) Peptic ulcer disease is the most common cause of upper GI bleeding in a 4-year-old. It would be unlikely for a 4-year-old to have an H pylori infection causing a GI bleed. GERD would have long-standing symptoms. Swallowed epistaxis is unlikely to cause hemodynamic changes in an otherwise healthy individual. Bleeding from esophageal varices would be associated with liver disease or portal vein thrombosis. Both are rare in this age group.

15. (C) Mallory-Weiss tears occur after several episodes of vomiting. The tear usually occurs in the gastroesophageal junction. In children the bleeding is usually self-limited (see Figure 48-4).

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FIGURE 48-4. Mallory-Weiss tear at the gastroesophageal junction. (Reproduced, with permission, from Fauci AS, Kasper DL, Braunwald E, et al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill; 2008: Fig. 285-18.)


16. (D) In developing countries, H pylori infections occur later in childhood. In the United States, the rate of infection in lower socioeconomic groups is much higher than for the population as a whole. GERD would be expected to have more symptoms. Herpetic esophagitis is very rare in immunocompetent hosts.

17. (D) Several tests are available to diagnose H pylori. Endoscopic mucosal biopsy is the most sensitive. The H pylori bacteria produce the enzyme urease. Christensen urea medium (CLO test) has a color change if H pylori is present in a biopsy specimen. Detection of serum IgG antibodies is sensitive and specific if done correctly. The sensitivity varies among commercial laboratories. Stool antigen tests are available but have lower sensitivity. Treatment consists of a proton pump inhibitor, clarithromycin, and amoxicillin or metronidazole.

18. (E) A small firm liver with a large spleen is characteristic of cirrhosis with portal hypertension. The bleeding can come from esophageal varices or gastropathy. The patient’s coagulopathy (from liver disease) and thrombocytopenia (from hypersplenism) must be corrected to stop the bleeding. Somatostatin infusions decrease the pressure in the splanchnic vascular bed and decrease portal pressure. The final treatment is an endoscopic procedure to determine the source of the bleeding and treat the varices. The most common treatments are banding and sclerotherapy. A variceal bleed can be a lifethreatening event, and more than 1 treatment modality may be necessary to treat it.


SUGGESTED READING

Fox VL. Gastrointestinal bleeding in infancy and childhood. Gastroenterol Clin North Am. 2000;29(1):37-66.

Heikenen JB, Pohl JF, Werlin SL, et al. Octreotide in pediatric patients. J Pediatr Gastroenterol Nutr. 2002;35(5):600-609.

Hyer W, Beveridge I, Domizio P, et al. Clinic management and genetics of gastrointestinal polyps in children. J Pediatr Gastroenterol Nutr. 2000;31(5):467-479.

CASE 49: A 6-WEEK-OLD WITH VOMITING

A 6-week-old boy comes to your office with several days of vomiting and irritability. He vomits “everything he eats.” The vomiting does not have any blood in it and is not associated with diarrhea or fever. The vomitus is described as being light in color but not green or yellow. The baby was born at full term with no complications. His birthweight was 3.2 kg.

On physical examination this is a well-nourished child: the weight is 4.4 kg, the HR is 180, and the RR is 38. His anterior fontanel is slightly sunken and there are dry mucous membranes. The abdomen is nondistended with normal bowel sounds. The remainder of the examination is unremarkable.

Laboratory studies-serum

Sodium (Na) 135 mEq/mL

Chloride (Cl) 99 mEq/mL

Potassium (K) 4.0 mEq/mL

Bicarbonate (HCO3) 30 mEq/mL

SELECT THE ONE BEST ANSWER

1. This child’s diagnosis most likely is

(A) GERD

(B) malrotation

(C) pyloric stenosis

(D) viral gastroenteritis

(E) urea cycle defect

2. The diagnostic test to confirm this diagnosis is

(A) pH probe

(B) upper GI series

(C) ultrasound of the abdomen

(D) serum NH3

(E) the diagnosis should be made on clinical grounds, and no further testing is necessary

3. If the laboratory investigation and physical examination were normal, the most likely diagnosis would be

(A) GERD

(B) malrotation

(C) pyloric stenosis

(D) viral gastroenteritis

(E) urea cycle disorder

4. The diagnostic test to confirm the condition in question 3 is

(A) pH probe

(B) upper GI series

(C) ultrasound of the abdomen

(D) upper endoscopy

(E) this is a diagnosis made on clinical grounds; no further testing is necessary

5. The first-line treatment for GERD includes

(A) surgery

(B) thickened feeds

(C) antacid medication

(D) change the infant’s formula

(E) B and C

6. If the child in the opening vignette had bilious vomiting, the most likely diagnosis would be

(A) duodenal atresia

(B) intestinal malrotation

(C) pyloric stenosis

(D) Hirschsprung disease

(E) intracranial hemorrhage

7. The least helpful diagnostic test you could use to confirm the condition in question 6 is

(A) abdominal radiograph

(B) barium enema

(C) upper GI series

(D) ultrasound

(E) CT

8. The true statement about Ladd bands is

(A) Ladd bands obstruct the duodenum

(B) Ladd bands can originate from the duodenum

(C) Ladds bands are peritoneal bands that can be associated with an annular pancreas

(D) Ladd bands can originate in the hepatic flexure

(E) all of the above

9. If the child in question 6 was 6 hours old and had Down syndrome, the likely diagnosis would be

(A) GERD

(B) malrotation

(C) duodenal atresia

(D) Hirschsprung disease

(E) atrioventricular (AV) canal malformation and heart failure

10. The diagnostic test you would order in this instance is

(A) abdominal radiograph

(B) upper GI series

(C) barium enema

(D) pH probe

(E) echocardiogram

11. When you go back and review this child’s prenatal ultrasound, you would likely see

(A) oligohydramnios

(B) the renal agenesis associated with this syndrome

(C) polyhydramnios

(D) hepatomegaly

(E) no consistent intrauterine finding

12. If the 6-hour-old infant with vomiting had a normal radiograph and a normal upper GI series but had a serum glucose of 20 mg/dL, your first step would be

(A) start ranitidine for the reflux

(B) start IV fluids with antibiotics

(C) encourage more oral feeds for hypoglycemia

(D) give IV glucose

(E) recheck the serum glucose

13. If the patient is a 2-year-old with vomiting and minimal abdominal pain who has normal vital signs, an Na of 130 mEq/mL and a HCOof 15 mEq/mL, the diagnosis is likely

(A) viral gastroenteritis

(B) malrotation

(C) GERD

(D) cyclic vomiting

(E) pancreatitis

14. Despite giving the patient in question 13 a fluid bolus, correcting the abnormal laboratory studies, and improving the vital signs, the child continues to vomit. Your next step is

(A) prochlorperazine suppository

(B) IV Hblocker

(C) IV ondansetron

(D) promethazine suppository

(E) upper GI series to rule out malrotation

15. The 2-year-old in question 13 has intermittent, severe cramping abdominal pain without diarrhea and between episodes has no symptoms. To make the diagnosis you need a

(A) blood culture

(B) upper GI series

(C) barium enema

(D) renal ultrasound

(E) CT of the abdomen

16. The 2-year-old vomits several times in the morning with no abdominal pain and has a normal physical examination. The remainder of the day he has no GI symptoms but is fussy. The likely diagnosis is

(A) GERD

(B) hydronephrosis

(C) intermittent volvulus

(D) brain tumor

(E) cyclic vomiting

17. The child in question 16 has 1 episode of “coffee ground” emesis. What is your concern?

(A) she needs more aggressive antacid therapy

(B) she needs endoscopy to rule out malignancy

(C) she needs an upper GI series because she likely has a malrotation

(D) A and C

(E) A, B, and C

18. The child in question 16 is noted to have weight loss, poor appetite, and a poor balance. Your first concern is which of the following?

(A) she needs more aggressive antacid therapy

(B) she needs a renal ultrasound

(C) she needs an upper GI series

(D) she needs a CT scan of the brain

(E) toxic ingestion

ANSWERS

1. (C) Pyloric stenosis is a thickening of the pylorus muscle. A patient usually becomes symptomatic after 3 weeks of age. It is characterized by nonbilious vomiting and hypochloremic alkalosis (see Figure 49-1).

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FIGURE 49-1. Hypertrophic pyloric stenosis. Note that the distal end of the hypertrophic muscle protrudes into the duodenum (arrow), accounting for the ease of perforation into the duodenum during pyloromyotomy. (Reproduced, with permission, from Doherty G. Current Diagnosis & Treatment: Surgery, 13th ed. New York: McGraw-Hill; 2010: Fig. 43-9.)


2. (C) The diagnosis of pyloric stenosis may be confirmed by palpation of the thickened pylorus on physical examination. The pylorus will be a firm, mobile olive-shaped mass. However, this is very difficult to palpate, and the diagnosis is usually confirmed on ultrasound. Although changes will be seen on an upper GI series, it has increased risk compared with ultrasound and is therefore not considered the best diagnostic test.

3. (A) GERD is the most common diagnosis for a healthy child with nonbilious vomiting. In a patient with severe viral gastroenteritis you would not expect normal vital signs, without fever or diarrhea.

4. (E) GERD is a clinical diagnosis. Although pH probes and endoscopy can be used to document changes consistent with reflux, neither is needed to confirm the diagnosis.

5. (B) The first-line treatments for reflux are conservative changes. These include limiting the volume the baby consumes per feed, positioning the baby upright after feeds, and thickening the child’s formula with 1 tablespoon of rice cereal per ounce. Infants who fail these measures should then undergo antacid therapy.

6. (B) Bilious vomiting is indicative of distal obstruction. The most common cause of obstruction in this age group is an intestinal malrotation (see Figure 49-2).

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FIGURE 49-2. Abdominal radiograph of a 10-day-old infant with bilious emesis. Note the dilated proximal bowel and the paucity of distal bowel gas, characteristic of a volvulus. (Reproduced, with permission, from Brunicardi FC, Andersen DK, Billiar TR, et al. Schwartz’s Principles of Surgery, 9th ed. New York: McGraw-Hill; 2010: Fig. 39-16.)


7. (A) In a malrotation, the duodenal jejunal loop is on the right side of the abdomen. The cecum is on the left side instead of the right. The malrotation occurs around the superior mesenteric vessel, and the superior mesenteric vein lies to the left of the artery instead of to the right. A barium enema can be used to locate the cecum, and an upper GI series can be used to visualize the duodenum. An ultrasound can be used to locate the superior mesenteric vessel. The least helpful test is a plain radiograph because a normal exam does not obviate the need for another imaging study (see Figure 49-3).

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FIGURE 49-3. Malrotation of the midgut with volvulus. Note cecum at the origin of the superior mesenteric vessels. Fibrous bands cross and obstruct the duodenum as they adhere to the cecum. Volvulus is untwisted in a counterclockwise direction. (Reproduced, with permission, from Doherty G. Current Diagnosis & Treatment: Surgery, 13th ed. New York: McGrawHill; 2010: Fig. 43-11.)


8. (A) Ladd bands are peritoneal bands that come from the malrotated cecum to the RUQ and can cause duodenal obstruction.

9. (C) Duodenal atresia is apparent in the first 24 hours of life. Thirty percent of children with duodenal atresia have Down syndrome.

10. (A) Abdominal radiograph will demonstrate the “double bubble” sign. There is gas in the stomach and the proximal duodenum but no gas in the distal bowel.

11. (C) The amniotic fluid produced cannot travel through a gut with an atresia. Therefore there is an excess (polyhydramnios) of fluid. Fifty percent of children with esophageal and duodenal atresia have polyhydramnios.

12. (D) Although the likely cause of hypoglycemia and vomiting is sepsis and further evaluation is indicated, it is imperative that the hypoglycemia be corrected immediately.

13. (A)

14. (C) Ondansetron is a serotonin 5-HTreceptor antagonist with excellent antiemetic effects. When given in the emergency department, ondansetron decreases vomiting and the need for hospital admission.

15. (C) The signs described are likely those of an intussusception but could be due to a malrotation with intermittent volvulus. A contrast enema could be used to diagnose either condition. If an upper GI study is performed and no diagnosis is made, the performance of a contrast enema may be delayed because of residual contrast material moving through the small bowel and interfering with the interpretation of the contrast enema.

16. (A) Although morning vomiting is concerning because of its association with central nervous system (CNS) pathology, in a patient with a normal physical examination and no other symptoms, the diagnosis is likely GERD.

17. (A) GI bleeding in this patient is likely secondary to peptic acid disease. GI malignancy in this age group is rare. Malrotation would be associated with abdominal pain and likely bilious emesis.

18. (D) Morning vomiting is concerning. In a patient who is having neurologic signs, not eating a normal diet, and losing weight, you must be concerned about a brain tumor.


SUGGESTED READING

Colleti RB, DiLorenzo C. Overview of pediatric gastroesophageal reflux disease and proton pump inhibitor therapy. J Pediatr Gastroenterol Nutr. 2003;37(suppl 1):7-11.

Maclennan AC. Investigations in vomiting children. Semin Pediatr Surg. 2003;12(4):220-228.

Reeves JJ, Shannon MW, Fleisher GR. Ondansetron decreases vomiting associated with acute gastroenteritis: a randomized controlled study. Pediatrics. 2002;109(4):e62.

CASE 50: AN 8-YEAR-OLD WITH JAUNDICE

An 8-year-old girl presents to your office with a 3-day history of decreased appetite and abdominal pain. She denies fever or diarrhea but has nausea and intermittent vomiting.

Physical examination reveals a jaundiced girl with a height and weight at the 50th percentile for age. The abdomen is soft and nondistended with positive bowel sounds, but the patient has diffuse RUQ pain and an enlarged liver without splenomegaly.

SELECT THE ONE BEST ANSWER

1. The most appropriate first test is

(A) hepatitis A antibody

(B) monospot test

(C) hepatitis B surface antigen

(D) hepatitis C antibody

(E) all of the above

2. If the patient in the vignette had not been jaundiced, your initial evaluation would include

(A) hepatitis A antibody

(B) monospot

(C) hepatitis B surface antigen

(D) hepatitis C antibody

(E) all of the above

3. If the hepatitis A serology is negative, the next step in your evaluation of this 8-year-old jaundiced child is

(A) hepatic function panel, PT, GGTP

(B) α1-antitrypsin level, ceruloplasmin

(C) anti-smooth muscle antibody, antinuclear antibody (ANA), anti-liver and kidney microsomal antibodies

(D) hepatitis B antigen, hepatitis C antibody

(E) all of the above

4. In Wilson disease

(A) serum ceruloplasmin is increased and the urinary copper is increased

(B) serum ceruloplasmin is decreased and the urinary copper is increased

(C) serum ceruloplasmin is increased and the urinary copper is decreased

(D) serum ceruloplasmin is decreased and the urinary copper is decreased

(E) normal serum ceruloplasmin level but increased urinary copper

5. Suppose the ceruloplasmin level is consistent with Wilson disease. Left untreated, the other organ system(s) most likely to be affected includes

(A) neuropsychiatric

(B) cardiac

(C) respiratory

(D) all of the above

(E) none of the above

6. In Wilson disease

(A) the inheritance is autosomal dominant and all family members should be screened for asymptomatic disease

(B) the inheritance is autosomal recessive and all family members should be screened for asymptomatic disease

(C) the inheritance is autosomal dominant; only symptomatic patients need to be treated so no screening is necessary

(D) the inheritance is autosomal recessive; only symptomatic patients need to be treated so no screening is necessary

(E) is caused by sporadic mutations and therefore there are never other family members affected by the disease

7. If the patient’s ANA titer is 1:640 and the anti-smooth muscle antibody is 1:320, the patient’s diagnosis is

(A) type 1 autoimmune hepatitis

(B) type 2 autoimmune hepatitis

(C) type 3 autoimmune hepatitis

(D) all of the above

(E) none of the above

8. The treatment for autoimmune hepatitis would include

(A) steroids

(B) ganciclovir

(C) lamivudine

(D) all of the above

(E) there is no effective medical treatment; referral to a transplant center is required

9. If the symptoms of the patient in the initial vignette were due to hepatitis B, the infection would be

(A) acute hepatitis B

(B) congenitally acquired chronic hepatitis B

(C) unknown because you need a hepatitis B surface antigen to be able to distinguish between acute and chronic infection

(D) unknown because you need a quantitative hepatitis B DNA level to distinguish between acute and chronic infection

(E) unknown because without further history, you cannot distinguish what type of hepatitis B infection the patient has

10. Had the patient in the vignette presented with a small firm liver, splenomegaly, and ascites, the disease that created these symptoms could have been any of the following, except

(A) hepatitis B

(B) Wilson disease

(C) type 1 autoimmune hepatitis

(D) hepatitis A

(E) hepatitis C

11. While you are awaiting the lab results in a jaundiced child, the patient’s mother calls to say she is “difficult to wake up.” Your next step is

(A) repeat her liver numbers

(B) see her in your office before repeating the labs

(C) increase her fluid intake because her lethargy is likely secondary to dehydration

(D) refer her to an emergency department for evaluation

(E) admit her and observe

12. Fulminant hepatic failure is defined as

(A) a patient with liver disease who develops encephalopathy and coagulopathy

(B) a patient with liver disease who develops encephalopathy

(C) a patient without preexisting liver disease who develops encephalopathy and coagulopathy within 8 weeks of the onset of liver disease

(D) a patient without preexisting liver disease who develops encephalopathy within 16 weeks of the onset of liver disease

(E) a patient without preexisting liver disease who develops coagulopathy within 16 weeks of the onset of liver disease

13. The problems that arise in children with fulminant hepatic failure include

(A) hypoglycemia

(B) coagulopathy

(C) renal failure

(D) encephalopathy

(E) all of the above

14. If the child in the initial vignette had been ill for several days with viral upper respiratory infection (URI) symptoms, which additional laboratory study would you order?

(A) adenovirus culture

(B) acetaminophen level

(C) enterovirus culture

(D) influenza A culture

(E) all of the above

15. If the acetaminophen level was high, the likelihood of successfully treating the patient’s toxicity is

(A) less likely than an asymptomatic patient

(B) more likely than an asymptomatic patient

(C) equivalent to an asymptomatic patient

(D) there are no data to predict the chance of successful treatment

(E) there is no known treatment for acetaminophen toxicity

16. Suppose the child was 2 years old and had RUQ pain and an enlarged liver. Suppose further that she was anicteric and the hepatitis A serology was negative. In this instance, the next step would be

(A) ultrasound and an alpha-fetoprotein level

(B) hepatitis B and C serology

(C) α1-antitrypsin level, ceruloplasmin

(D) ANA, anti-smooth muscle antibody, anti-liver kidney microsomal antibody determinations

(E) all of the above

17. The likely diagnosis for that patient is

(A) hepatocellular carcinoma

(B) hepatoblastoma

(C) rhabdosarcoma

(D) angiosarcoma

(E) metastatic disease from another primary tumor

18. If a young child (2-8 years old) had a sudden onset of RUQ pain, fever, and jaundice, the likely diagnosis would be

(A) cholecystitis

(B) choledochal cyst

(C) sclerosing cholangitis

(D) cholangiocarcinoma

(E) liver hematoma

ANSWERS

1. (A) A child with RUQ pain and jaundice must be assumed to have some form of hepatitis. Hepatitis A causes 50% of acute hepatitis in the United States. Transmission is via person to person or by water- and foodborne outbreaks. In utero maternal-child transmission has not been recognized. The incubation period is about 4 weeks. Most children have vague symptoms: low-grade fever, nausea, vomiting, and hepatomegaly. The vast majority of young children are anicteric. The disease is self-limited in the great majority of cases. Young children can have anicteric hepatitis A.

2. (A) See above explanation. Acute Epstein-Barr virus (EBV) infections frequently cause hepatomegaly but almost always there are other associated symptoms (fever, lymphadenopathy, sore throat, fatigue, and splenomegaly). Patients with hepatitis B infection are jaundiced.

3. (E) Table 50-1 lists the differential diagnosis and the appropriate tests required.

TABLE 50-1. Differential Diagnosis of Jaundice in the Older Child

 

DISEASE

DIAGNOSTIC TEST

 

α1-antitrypsin deficiency

α1-antitrypsin level, protease inhibitor type

Wilson disease

Ceruloplasmin, urine copper, dry weight of copper in liver

Type 1 autoimmune hepatitis

ANA, anti-smooth muscle antibody

Type 2 autoimmune hepatitis

Anti-liver kidney microsomal antibody

Hepatitis B

Hepatitis B surface antigen

Hepatitis C

Hepatitis C antibody

 

4. (B) The pathophysiology of Wilson disease is an inability to mobilize copper from lysosomes within the hepatocytes. When the liver has reached its storage capacity, the copper escapes and begins to damage other organ systems. There is an increase in urinary copper. There are neuropsychological symptoms, renal disease, and hemolysis. Copper is needed but not available for production of ceruloplasmin. Therefore the level is low.

5. (A) See above explanation.

6. (B) Wilson disease has an autosomal recessive inheritance. Patients are more effectively treated before symptoms occur; therefore all family members should be screened for asymptomatic disease.

7. (A) Type 1 autoimmune hepatitis is associated with a positive ANA and anti-smooth muscle antibody. Type 2 autoimmune hepatitis is associated with anti-liver and kidney microsomal antibodies. There is no type 3.

8. (A) The treatment for autoimmune hepatitis is steroids and azathioprine. Once the liver numbers have returned to the normal range, the initial high dose of steroids can be weaned. There is no infectious etiology known for the disease; therefore antivirals (ganciclovir and lamivudine) would not be appropriate.

9. (B) Hepatitis B is transmitted by the percutaneous route, use of IV drugs, sexual contact, or in utero maternal-child transmission. There are reports of household contact spread, but because hepatitis B vaccination is part of routine pediatric care it is less likely she would be infected from a household contact. An 8-year-old is likely to have acquired the infection from mother at birth. This child would therefore have a chronic infection. See Table 50-2 to interpret the markers, which distinguish acute from chronic infection.

10. (D) The description here is of cirrhosis with evidence of portal hypertension, secondary to chronic liver disease. Although hepatitis A can rarely cause fulminant hepatic failure, it does not have a chronic form. The other listed diseases do.

11. (D) A child who is jaundiced and then is “difficult to wake up” must be assumed to have encephalopathy. This should be evaluated in an emergency department where laboratory evaluations and treatment are immediately available.

12. (C)

13. (E) Patients with fulminant hepatic failure (FHF) have a decreased liver mass. They are at risk for hypoglycemia secondary to decreased glycogen storage and gluconeogenesis. Such a patient may develop hepatorenal syndrome. The mechanism is unknown, but the disease is characterized by decreased excretion of Na (as opposed to acute tubular necrosis where Na excretion is increased). Coagulopathy develops because the liver produces factors I (fibrinogen), II, V, VII, IX, and X. In addition in FHF there is frequently DIC contributing to the coagulopathy that may be difficult to control. Encephalopathy is characteristic of hepatic failure (see Figure 50-1).

TABLE 50-2. Serum Markers in Hepatitis B Infections

 
 

HBsAg

HBsAb

HBc Igm

HBc IgG

HBeAg

HBeAb

HB DNA

 

Early acute

+

+

+

+

Late acute

+

+

+

+

Chronic

+

+

+

+

 

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FIGURE 50-1. Hepatic pathology of fulminant hepatic failure. A. Gross liver section demonstrating regenerative nodules after FHF. B. High-power view demonstrating necrosis with lack of hepatocytes and intact portal structures. C. High -power view with reticulin stain showing nodular liver regeneration. (Reproduced, with permission, from Hall JB, Schmidt GA, Wood LDH. Principles of Critical Care, 3rd ed. New York: McGraw-Hill; 2005: Fig. 83-1A-C.)


14. (B) In a patient who has been ill, acetaminophen toxicity must be included in the differential diagnosis. Parents who give acetaminophen frequently can inadvertently overdose a child. In a teenager, you must be concerned about intentional overdose. The viral illnesses listed would not cause liver disease in a previously healthy 8-year-old.

15. (A) The treatment for acetaminophen toxicity is Nacetyl-cysteine. The treatment is most effective if given within the first 10 hours after ingestion. Jaundice and increased liver numbers occur 3 days after the ingestion. Although the N-acetyl-cysteine may be less effective after that time, it is still given.

16. (A) The description of a 2-year-old with a large liver unexplained by a viral illness (eg, hepatitis) is characteristic of hepatic malignancy. The initial evaluations would include an ultrasound and a serum alpha-fetoprotein level. Wilson disease does not present before age 4-5 years. Autoimmune hepatitis rarely presents at 2 years old. The presentation for α1 antitrypsin deficiency or hepatitis B or C in this age group would be an asymptomatic elevation in the ALT and AST.

17. (B) The most common hepatic malignancy in this age group is hepatoblastoma. Hepatocellular carcinoma presents in older children and is usually associated with hepatitis B or C. Rhabdosarcomas and angiosarcomas are rare.

18. (B) The description is the classic presentation for a choledochal cyst in this age group. Choledochal cysts can present as neonatal cholestasis. Gallstones are incredibly rare in children. Sclerosing cholangitis and cholangiocarcinoma do not have acute presentations.


SUGGESTED READING

Bezerra JA, Balistreri W. Cholestatic syndromes in infancy and childhood. Semin Gastrointest Dis. 2001;12(2):54-65.

Schwarz K, Balistreri W. Viral hepatitis. J Pediatr Gastroenterol Nutr. 2002;35(suppl 1):S29-S32.

Whitington PF, Soriano HE, Alonso EM. Fulminant hepatic failure. In: Suchy F, ed., Liver Disease in Children. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2007.

CASE 51: A 6-YEAR-OLD WITH FECAL INCONTINENCE

A 6-year-old boy presents with a complaint of fecal incontinence. His mother reports he stools every other day in the toilet but in between he has 4-6 “accidents.” The mother denies abdominal distention, decreased appetite, or nausea.

Physical examination shows his height and weight to be at the 50th percentile. The abdomen is soft, with normal bowel sounds and no palpable liver or spleen. Examination of the head, ears, eyes, nose, and throat is normal. Similarly, the cardiac and respiratory examinations are normal.

SELECT THE ONE BEST ANSWER

1. Your most important next step is

(A) barium enema

(B) rectal exam

(C) lumbar spine MRI

(D) to start a behavioral program for bowel training

(E) reassure Mom he will outgrow this problem

2. If this was a low-segment Hirschsprung disease, you would expect

(A) increased rectal tone compared with functional constipation

(B) decreased rectal tone compared with functional constipation

(C) the same rectal tone compared with functional constipation

(D) normal rectal tone

(E) a presentation in infancy

3. If the child has a sacral dimple, then associated clinical feature(s) may include

(A) urinary incontinence

(B) loss of lower extremity reflexes

(C) anterior placed anus

(D) A and B

(E) A, B, and C

4. The most appropriate next step in the management for the patient in question 3 is

(A) rectal examination

(B) abdominal radiograph

(C) barium enema

(D) lumbosacral spine MRI

(E) to start a behavioral program for bowel training

5. The child in the vignette has a large amount of hard stool and decreased tone on his rectal examination. The next diagnostic test is

(A) abdominal radiograph

(B) barium enema

(C) lumbar spine MRI

(D) colonoscopy

(E) none necessary

6. The treatment for the child in question 5 includes

(A) dietary intervention

(B) enema

(C) osmotic laxatives

(D) behavioral intervention

(E) all of the above

7. The length of time this child will need to be treated is

(A) 1 week

(B) 2 weeks

(C) 3 weeks

(D) more than 6 months

(E) once laxative therapy is initiated, it is lifelong

8. The chance of successfully weaning all laxatives after a year is

(A) 10%

(B) 30-50%

(C) 50-75%

(D) 75-90%

(E) more than 90%

9. If the child in the vignette had rectal prolapse with his constipation, the next step would be

(A) a sweat test

(B) a rectal biopsy

(C) to treat the constipation

(D) to do a detailed calorie count

(E) nothing

10. Had the weight and height of the child in the vignette been less than the 5th percentile for age and there was rectal prolapse, your next step would be

(A) a sweat test

(B) a rectal biopsy

(C) to treat the constipation

(D) to do a detailed calorie count

(E) nothing

11. Had the child in the vignette been treated for urinary incontinence by a urologist and his constipation began after his treatment

(A) the constipation and urinary incontinence are secondary to a spinal tumor

(B) urinary incontinence is usually treated with anticholinergics and the constipation is secondary to the drug

(C) the constipation was previously undiagnosed and the urinary incontinence is secondary to the constipation

(D) B or C

(E) none of the above

12. Had the child in the vignette had painless bright red blood per rectum, the likely diagnosis would be

(A) juvenile polyp

(B) fissure

(C) hemorrhoid

(D) Meckel diverticulum

(E) colon cancer

13. If this child was 6 weeks old, breast-fed, and stooled once every 5 days, the management would include

(A) reassurance

(B) mineral oil

(C) malt soup extract (a diastatic barley malt extract)

(D) rectal stimulation

(E) stop breastfeeding

14. If the child in question 13 was in a good disposition but a poor feeder with constipation, your first step is

(A) a barium enema

(B) a rectal biopsy

(C) TSH and thyroxine (T4) determinations

(D) a sweat test

(E) treat for reflux to help improve fluid intake

15. Regarding Hirschsprung disease, which statement is true?

(A) male-to-female ratio is 4:1

(B) female-to-male ratio is 4:1

(C) there is an equal gender distribution

(D) male-to-female ratio is 8:1

(E) female-to-male ratio is 8:1

16. In an infant with Hirschsprung disease, the findings on physical examination include

(A) empty rectum

(B) rectal impaction

(C) abdominal distention

(D) A and C

(E) B and C

17. The findings with Hirschsprung disease on barium enema would be

(A) a transition zone between the dilated aganglionic section and the normal colon

(B) a transition zone between the contracted aganglionic section and the dilated colon

(C) a transition zone between the rectum and the dilated colon

(D) a transition zone between the descending and transverse colon

(E) there are no consistent findings on barium enema and rectal biopsy is the diagnostic test of choice

18. The true statement about children with Hirschsprung disease is

(A) more than 90% do not pass meconium in the first 24 hours of life

(B) 75% do not pass meconium in the first 24 hours of life

(C) 50% do not pass meconium in the first 24 hours of life

(D) 25% do not pass meconium in the first 24 hours of life

(E) the history of when they pass meconium is unimportant

ANSWERS

1. (B) A rectal examination is the part of the physical examination that gives you the best information in this case. A patient with functional constipation and encopresis described in this vignette is going to have loose rectal tone and stool within the vault.

2. (A) Children with Hirschsprung disease have aganglionosis in certain sections of the colon. A 6-yearold presenting with Hirschsprung disease would have an ultrashort segment of Hirschsprung involvement. The rectal tone is increased in Hirschsprung disease. The vault is likely to be empty.

3. (D) Spina bifida, meningomyelocele, sacral agenesis, and spinal cord tumors can be associated with fecal incontinence. Other neurologic symptoms and signs such as urinary incontinence and loss of reflexes can be associated.

4. (D) Evaluation of the spine by an MRI is the most appropriate diagnostic test.

5. (E) Functional constipation is a clinical diagnosis. The vignette and the rectal examination findings are consistent with functional constipation.

6. (E) The aim of therapy is to alleviate the impaction, prevent recurrence, and retrain the child to appreciate normal bowel signals. Any and all of the therapies listed are appropriate.

7. (D) Once a child has developed encopresis and is successfully treated by the plan outlined above, the laxatives must be weaned slowly. This will frequently take more than 6 months. Parents should be counseled about the length of time it takes to treat.

8. (B) The chance of successfully weaning children off all laxatives and having normal bowel habits is 30-50% at 1 year but only 78% at 5 years.

9. (C) Rectal prolapse is frequently associated with severe constipation. In developing countries, it is associated with malnutrition. There is also an association with cystic fibrosis (CF), but these patients usually have loose oily stools. In a child who has constipation and no other problems, it is unnecessary to look for CF simply because of rectal prolapse (see Figure 51-1).

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FIGURE 51-1. Prolapsed Rectum. Recurrent rectal prolapse due to chronic constipation. (Reproduced, with permission, from Knoop KJ, Stack LB, Storrow AS, et al. Atlas of Emergency Medicine, 3rd ed. New York: McGraw-Hill; 2010:228. Photo contributor: Lawrence B. Stack, MD.)


10. (A) In a child who has other symptoms possibly attributed to CF the sweat test is not necessary. In this instance, the small stature “tips the scale” to doing the sweat test.

11. (D) Because constipation and urinary symptoms frequently occur together, it is important to treat both ailments. It is important to remember also to look closely for constipation when a child presents with urinary incontinence. The treatment with anticholinergic drugs can lead to constipation. Drugs associated with constipation include analgesics, antacids, anticholinergic, bismuth, iron, cholestyramine, and antipsychotics.

12. (A) Painless bright red blood is likely to be a polyp in a child in this age group. Although hemorrhoids are associated with constipation in adults, they are very unusual in children. Fissures lead to painful bleeding. A Meckel diverticulum can cause a significant bleed, but usually the blood is not bright red.

13. (A) It is not the frequency of stool that defines constipation. In breast-fed babies there can be stools ranging from several times a day to once every several days. As long as the stool is of normal consistency and easily passed, several days between stools is normal.

14. (C) A 6-week-old in good disposition, but with poor feeding and constipation is concerning. Poor feeding secondary to abdominal pain or reflux is usually associated with an irritable baby. Here you must be concerned with hypothyroidism. The signs can be subtle.

15. (A)

16. (D) The physical findings consistent with Hirschsprung include increased rectal tone, lack of stool in the vault, and abdominal distention. The treatment involves resection of the poorly innervated colon. The most dangerous complications are enterocolitis and toxic megacolon. With this latter diagnosis, the baby presents with explosive diarrhea, fever, and shock.

17. (B) The aganglionotic area is contracted, hence the increased tone on rectal examination. The proximal colon will be dilated. The barium enema is diagnostic in more than 75% of patients with Hirschsprung.

18. (A)


SUGGESTED READING

DiLorenzo C, Benniga MA. Pathophysiology of pediatric fecal incontinence. Gastroenterology. 2004;126(1 suppl 1):S33-S40.

Loening-Baucke V. Encopresis. Curr Opin Pediatr. 2002; 14(5):570-575.

CASE 52: A 15-MONTH-OLD WITH DIARRHEA

A 15-month-old boy presents with a complaint of diarrhea. He is having 3-5 large “explosive” stools per day for 8 weeks. They are not malodorous, there is no blood or mucus, and they are not bulky or oily. Mom frequently sees food particles such as corn, carrots, and raisins in the stool.

On physical examination his vitals signs are HR 102, RR 28, and blood pressure (BP) 88/50. He is in no apparent distress. His breath sounds are equal and clear. His abdomen is nondistended with positive bowel sounds. There are no masses and no hepatosplenomegaly. There are no perianal lesions and the stool is heme negative. His growth curve is shown in Figure Figure 52-1.

SELECT THE ONE BEST ANSWER

1. The first studies you would order include

(A) stool for fat, reducing substances, and pH

(B) a stool culture and assay for fecal leukocytes

(C) stool examination for ova and parasites

(D) all of the above

(E) none of the above

2. The likely diagnosis for this child is

(A) nonspecific diarrhea of childhood (toddler’s diarrhea)

(B) carbohydrate malabsorption

(C) postinfectious malabsorption

(D) bacterial infection

(E) you cannot distinguish among these entities

3. Chronic diarrhea of childhood can be secondary to

(A) excess intake of fruit juice

(B) excess intake of carbohydrate

(C) too little fat in the child’s diet

(D) all of the above

(E) none of the above

4. The treatment for chronic nonspecific diarrhea includes

(A) reassurance and limiting dietary excess

(B) clear liquids when the number of stools is more than 5 per day

(C) diphenoxylate/atropine when the number of stools is more than 5 per day

(D) A and B

(E) B and C

5. If the growth curve for the child in the vignette was the curve in Figure 52-2, your concern would be

(A) celiac disease

(B) early Crohn disease

(C) chronic Giardia infection

(D) growth hormone deficiency

(E) CF

6. The laboratory studies that would allow you to make the diagnosis include

(A) hydrogen breath test

(B) CBC, sedimentation rate, and serum albumin

(C) tissue transglutaminase IgA

(D) pANCA

(E) A and C

7. Treatment for celiac disease includes

(A) gluten-free diet

(B) evaluation for hypothyroidism

(C) evaluation for anemia

(D) all of the above

(E) none of the above

8. In a child with a history of growth failure associated with rectal prolapse and chronic diarrhea, which of the following tests would likely be abnormal?

(A) stool examination for ova and parasites

(B) stool evaluation for reducing substances

(C) stool evaluation for fat content

(D) stool culture

(E) all of the above

9. The most appropriate next test for the child in question 8 is

(A) abdominal radiograph

(B) barium enema

(C) sweat test

(D) endoscopy

(E) food allergy testing

art

FIGURE 52-1.


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FIGURE 52-2.


10. Later in life, the child in question 8 may suffer from

(A) constipation

(B) distal intestinal obstruction syndrome (DIOS; a meconium ileus equivalent)

(C) focal biliary cirrhosis

(D) GERD

(E) all of the above

11. If the patient was 5 years old and had a history of duodenal atresia repair, the additional tests you would order include

(A) upper GI series with small bowel follow-through

(B) hydrogen breath test

(C) endoscopy with biopsy

(D) upper endoscopy with biopsy

(E) CT scan of the abdomen and pelvis with triple contrast

12. If the child had stools that “burned,” the likely malabsorption would be

(A) carbohydrate

(B) fats

(C) proteins

(D) vitamins and minerals

(E) bicarbonate

13. If the stools were described as covered with mucus and were heme positive, the patient’s history would likely include

(A) exposure to well water

(B) exposure to antibiotics

(C) exposure to other ill children

(D) family history of inflammatory bowel disease

(E) history of lactose intolerance

14. The antibiotic that most often leads to C difficile infection in pediatric patients is

(A) amoxicillin

(B) clindamycin

(C) erythromycin

(D) cefdinir

(E) all of the above cause an equal incidence of C difficile

15. If the child was 6 week old with 5 loose watery stools with blood daily, the most likely diagnosis is

(A) infectious colitis

(B) protein intolerance

(C) lactose intolerance

(D) congenital C1-losing diarrhea

(E) fat malabsorption

16. If the child was feeding on a cow’s milk lactosecontaining formula, the treatment would be

(A) soy formula

(B) hydrolyzed formula

(C) cow’s milk lactose-free formula

(D) await stool culture results before making recommendations

(E) await stool electrolytes before making recommendations

17. If the child in question 15 was being breast-fed, then the treatment would be

(A) soy formula

(B) hydrolyzed formula

(C) await stool cultures

(D) restrict the cow’s milk in Mom’s diet

(E) lactose-free formula

18. A microbiology lab calls you with a report of a positive C difficile toxin result on a 10-day-old patient of yours. Your treatment plan would be

(A) extended and more aggressive compared with older children because of the increased chance of catastrophic complications in this age group

(B) the same as older children because age has no effect on the chance of catastrophic complications

(C) shortened compared with older children because of the decreased chance of catastrophic complications in this age group

(D) to retest to confirm diagnosis before beginning therapy

(E) no treatment is indicated

ANSWERS

1. (E) The initial evaluation of a child with chronic diarrhea should concentrate on the history and physical examination. This child is healthy and growing normally in all respects. This is typical of toddler’s diarrhea and should be handled with education and reassurance. The screening laboratory tests listed are examinations of the stool looking for malabsorption and intestinal infection; these diagnoses would not be suspected in this patient from the history or physical examination.

2. (A) A 15-month-old child who has normal growth and diarrhea without accompanying GI symptoms likely has nonspecific diarrhea of childhood. Parents will frequently see food in the stool. The symptoms of carbohydrate malabsorption are detailed below. There was no history of gastroenteritis before the onset of this diarrhea.

3. (D) Nonspecific diarrhea of childhood can occur because of any of the dietary problems listed. Children can have increased diarrhea if they are put on a clear liquid diet frequently.

4. (A) Reassurance and restricting the dietary excesses are the best initial treatments.

5. (A) This is a classic growth curve for celiac disease. This patient’s growth retardation began at approximately 6 months of age, which is typically when gluten-containing foods are introduced to the diet. It would be very unusual for Crohn disease to present at 6 months of age. CF would very likely cause malnutrition from birth.

6. (C) The evaluation of a child suspected to have celiac disease initially should be serologic. Detection of antigliadin antibodies is a sensitive test but not specific to Celiac disease, and these antibodies can be present in other GI diseases. Detection of antiendomysial antibodies is much more specific. Tissue transglutaminase is a specific antiendomysial antibody. Caution should be used in interpretation because 2-5% of celiac patients are IgA deficient and have a false-negative test result.

7. (D) The treatment for celiac disease is a gluten-free diet. These patients also have a high incidence of associated hypothyroidism and iron deficiency anemia.

8. (C) A patient with diarrhea, growth failure, and rectal prolapse has CF until proven otherwise. The fat content in the stool will be abnormal secondary to pancreatic insufficiency that commonly occurs in CF patients.

9. (C) A sweat test should be done to ensure the clinical findings are from CF. Although gene testing for CF is readily available and may aid in predicting long-term prognosis and genetic counseling, a properly performed sweat test can provide a rapid and accurate diagnosis that allows for immediate initiation of therapies. Without other signs or symptoms, imaging studies, endoscopy, and allergy testing are not indicated.

10. (E) Later in life, children with CF can suffer from multiple GI symptoms. Constipation and GERD are commonly associated symptoms. DIOS presents with partial or complete bowel obstruction. It responds to medical therapy with gastrografin enemas. It can recur. In chronic cases, it is important to ensure there is adequate pancreatic enzyme replacement. About 2-3% of CF patients develop biliary cirrhosis.

11. (B) Patients with previous bowel surgery are predisposed to have bacterial overgrowth. This can be diagnosed with a breath hydrogen test. The patient ingests sugar that bacteria convert into hydrogen. In small bowel bacterial overgrowth, the peak of expired hydrogen will be early because the bacteria are in the small bowel, not the colon. In carbohydrate malabsorption there will be a later peak when the unabsorbed sugar reaches the colon. Without signs of obstruction or perforation, radiographic studies are not indicated. Endoscopy would not aid in this diagnosis.

12. (A) Carbohydrate malabsorption leads to delivery of unabsorbed carbohydrate to the colon. The bacteria in the colon convert it to acid. Reducing substances will be positive.

13. (B) The stool description is consistent with C difficile infection. Although there is an increasing incidence of community-acquired C difficile, most cases in children are associated with recent antibiotic exposure. Well water exposure would raise the concern for parasitic infection, and exposure to other sick children would likely indicate a viral gastroenteritis. Both of these are unlikely to yield mucoid or heme-positive stool. Lactose intolerance would likely lead to increased gas and bloating with loose, watery, and acidic stools.

14. (A) Although in adults clindamycin is the antibiotic most associated with C difficile, in pediatrics many more patients take amoxicillin; therefore it is the antibiotic most frequently associated with C difficile. This situation may change as epidemic community-acquired methicillin-resistance Staphylococcus aureus (MRSA) necessitates increasing use of clindamycin.

15. (B) Although infectious causes are always possible, the most common cause of diarrhea in this age group is protein intolerance. Lactose intolerance presents with increased gas and bloating with loose watery, nonbloody stools and is rare in this age group. Children with congenital C1-losing diarrhea present earlier and are very ill. Fat malabsorption presents with foul smelling, oily, nonbloody stool

16. (B) The intolerance is to the cow’s milk protein. Up to 50% of those children will also be allergic to soy formula. Going directly to a hydrolyzed formula is indicated for these patients. The presence or absence of lactose is not relevant to this patient’s symptoms.

17. (D) The symptoms are due to exposure to cow’s milk protein. The treatment is to restrict the exposure to cow’s milk, components of which can cross into the mother’s breast milk.

18. (E) Up to 70% of infants will be carriers of C difficile and no treatment is necessary even when the toxin is detected. The toxin receptor is absent from the intestinal cells of a neonate.


SUGGESTED READING

Book L. Diagnosing celiac disease in 2002: who, why, and how. Pediatrics. 2002;109:952-954.

Leung AK, Robson WL. Evaluating the child with chronic diarrhea. Am Fam Physician. 1996;53:635-643.

Pietzak MM, Thomas DW. Childhood malabsorption. Pediatr Rev. 2003;24:195-206.