Symptom-Based Diagnosis in Pediatrics (CHOP Morning Report) 1st Ed.

CASE 3-6

Ten-Month-Old Girl

JOANNE N. WOOD

HISTORY OF PRESENT ILLNESS

The patient is a 10-month-old female who presents with a 1-day history of vomiting and fever to 38.3°C. The emesis is nonbloody and nonbilious. She has a history of constipation and failure to thrive. She has had no recent changes in her stooling pattern of one hard bowel movement per week. Stooling is painful but is not associated with blood or mucous. Her mother uses prune juice, karo syrup, and laxatives to aid in bowel movements. The patient has had decreased oral intake for the past day with mild decreased urine output. Her mother also reports that the patient always has a distended abdomen.

MEDICAL HISTORY

She was born via spontaneous vaginal delivery at 39 weeks after an uncomplicated pregnancy. Her mother reports that the patient has been constipated since birth. She did not pass meconium prior to being discharged from the nursery on day 2 of life. She has a history of failure to thrive. She was growing at the 50th percentile until 4 months of age when her weight gain slowed and she began to cross percentiles on the growth curve. She also has a history of anemia, hypotonia, and developmental delay.

PHYSICAL EXAMINATION

T 38.7°C; RR 56/min; HR 150/min; BP 92/50 mmHg

Weight (6.2 kg); Length (66 cm); and Head circumference (40.5 cm), all significantly less than the 5th percentile for age

General examination revealed a pale, crying infant. Her heart and lungs were normal. Her abdomen was distended, tender with hypoactive bowel sounds, and a palpable mass in the right lower quadrant. There was no hepatomegaly or splenomegaly. Her neurologic examination was notable for general hypotonia.

DIAGNOSTIC STUDIES

Laboratory evaluation revealed 25 000 white blood cells/mm3 with 81% segmented neutrophils, 10% lymphocytes, and 6% monocytes. The hemoglobin was 8.7 g/dL with hypochromia, occasional schistocytes, and burr cells. The MCV was 74.6 fL, the RDW was 23.2, and the reticulocyte count was 2.2%. The platelet count was 649 000 cells/mm3. Serum chemistries were as follows: sodium, 137 mEq/L; potassium, 4.9 mEq/L; chloride, 115 mEq/L; bicarbonate, 18 mEq/L; blood urea nitrogen, 3 mg/dL; creatinine, 0.2 mg/dL; glucose, 98 mg/dL; alkaline phosphatase, 77 U/L; total bilirubin, 0.8 mg/dL; ALT, 98 U/L; and AST, 156 U/L.

COURSE OF ILLNESS

The chest radiograph was normal. An abdominal radiograph revealed findings that lead to an immediate therapeutic procedure (Figure 3-10).

Image

FIGURE 3-10. Abdominal radiograph.

DISCUSSION CASE 3-6

DIFFERENTIAL DIAGNOSIS

The abdominal radiograph revealed large pneumoperitoneum in this infant. Pneumoperitoneum on radiograph in a vomiting child with a distended, tender abdomen, and a palpable mass in the right lower quadrant, is a perforated hollow viscous until proven otherwise and requires immediate surgical exploration. Once the perforation is identified and repaired, the etiology of the perforation must be discovered and corrected.

In this case, the medical history of constipation since infancy suggests a potential underlying cause of the perforation. The differential diagnosis of constipation includes nonorganic or functional constipation, anatomic malformations (imperforate or anteriorly placed anus, stricture), abnormal abdominal musculature (prune-belly syndrome, gastroschisis, Down syndrome), intestinal nerve or muscle abnormalities (Hirschsprung disease, pseudo-obstruction secondary to visceral myopathies and neuropathies), metabolic/endocrine disorders (hypothyroidism, hypercalcemia, hypokalemia), spinal cord defects, drugs, intestinal disorders (celiac disease, inflammatory bowel disease, cystic fibrosis, cow’s milk protein intolerance, tumor), connective tissue disorders, and botulism. Although in the majority of pediatric cases, constipation is attributed to nonorganic or functional constipation, there are features in this child’s history that suggest an organic etiology. A history of hard stools that are passed only with difficulty in the neonatal period is suggestive of Hirschsprung disease, visceral myopathy, visceral neuropathy, or hypothyroidism. The delayed passage of meconium after 24 hours of life adds to the concern for Hirschsprung disease. In an infant with constipation and a history of delayed meconium cystic fibrosis should also be considered if an evaluation for Hirschsprung disease is negative. The history of failure to thrive and abdominal distention as well as the acute presentation with fever and vomiting also point to an organic etiology and are consistent with Hirschsprung disease.

DIAGNOSIS

The abdominal radiograph showed a moderate amount of free air in the abdomen suggesting bowel perforation (Figure 3-10). The patient was taken to the operating room where a large rush of air was felt upon entering the abdominal cavity. A massively dilated colon was discovered and an 18-cm segment of the colon was resected after a 3-mm perforation was found in the sigmoid colon. Pathologic review of the resected segment confirmed the diagnosis of Hirschsprung disease.

INCIDENCE AND EPIDEMIOLOGY OF HIRSCHSPRUNG DISEASE

Hirschsprung disease, the most common congenital cause of gut motility disorder, has an incidence of 1 in 5000 live births. Males are affected 2 to 4 times more often than females.

CLINICAL PRESENTATION

The clinical presentation of patients with Hirschsprung disease depends on the length of the aganglionic segment. In Hirschsprung disease, a failure in the craniocaudal migration of vagally derived neural crest cells in the hindgut during fetal development results in an aganglionic segment in the distal gut. The majority of cases (75%-80%) are classified as short-segment Hirschsprung disease because the aganglionosis is limited to the rectosigmoid area. In 20% of cases, long-segment Hirschsprung disease, aganglionosis extends proximal to the sigmoid. In less common variants of Hirschsprung disease the entire colon, the entire bowel, or only the distal rectum and anus are affected.

Most cases of Hirschsprung disease present in the neonatal period with failure to pass meconium within the first 24 hours of life and symptoms of intestinal obstruction including vomiting, abdominal distention, and refusal to feed. The passage of meconium occurs within the first 24 hours of life in more than 90% of normal neonates but in less than 10% of neonates with Hirschsprung disease. Some cases of short-segment Hirschsprung disease are detected later in infancy or childhood due to severe constipation with ribbon-like stools, persistent abdominal distention, vomiting, failure to thrive, and a rectum devoid of stool. Patients can also present with Hirschsprung’s-associated enterocolitis which has a mortality of 20%. The signs and symptoms of HAEC may include fever, abdominal distension, foul-smelling stool, explosive diarrhea, vomiting, lethargy, rectal bleeding, and shock.

In the majority of cases Hirschsprung disease is an isolated disorder, but in 12% of cases it is associated with a chromosomal abnormality, and in 18% of cases it is associated with other congenital anomalies. Down syndrome is the most common chromosomal abnormality associated with Hirschsprung disease. Other syndromes associated with Hirschsprung disease include Smith-Lemli-Opitz syndrome, Waardenburg syndrome, Mowat-Wilson syndrome, congenital central hypoventilation syndrome, and Goldberg-Shprintzen syndrome.

DIAGNOSTIC APPROACH

A thorough history and physical examination should be performed in any child presenting with constipation. A history of delayed passage of meconium and signs of intestinal obstruction should prompt consideration of Hirschsprung disease. A history of ribbon-like stool, failure to thrive, and abdominal distention in an older child with severe constipation since birth should also lead to evaluation for Hirschsprung disease. The sudden onset of fever, abdominal distention, and foul-smelling explosive stool in a child with constipation raises concern for Hirschsprung’s-associated enterocolitis.

A child with suspected Hirschsprung disease should be evaluated in a medical center with the facilities to perform the necessary diagnostic tests and the availability of pediatric gastroenterologists and pediatric surgeons. Evaluation should not be delayed as a delay in diagnosis and treatment increases the risk of Hirschsprung’s-associated enterocolitis. There are multiple tests that may be helpful in diagnosing Hirschsprung disease, but rectal suction biopsy and anorectal manometry are the only tests that can reliably be used to exclude a diagnosis of Hirschsprung disease.

Abdominal radiographs. Plain abdominal radio-graphs in infants with Hirschsprung disease may show gaseous distention of the colon with a paucity of air in the rectum and a zone of transition in between.

Barium enema. In cases of Hirschsprung disease, a barium enema may show a zone of transition between a normally dilated proximal colon and the narrower aganglionic distal segment, irregular colonic contractions, irregular colonic mucosa, or an abnormal rectosigmoid index. A barium enema should not be used to diagnose Hirschsprung disease because of the risk of false negatives and false positives. Once a diagnosis of Hirschsprung disease is made, however, barium enema may be useful in determining the extent of the affected bowel. Also, barium enemas should not be performed if Hirschsprung’s-associated enterocolitis is suspected due to the risk of perforation.

Anorectal manometry. The demonstration of a normal reflex relaxation of the internal anal sphincter in response to inflation of a balloon in the rectum can exclude a diagnosis of Hirschsprung disease. The test, however, can be difficult to perform and interpret in young infants.

Rectal biopsy. Rectal suction biopsy is the gold standard test for Hirschsprung disease. The presence of acetylcholinesteras positive nerve fibers and absence of ganglion is diagnostic for Hirschsprung disease. Occasionally, a full thickness rectal biopsy is needed if the suction biopsy is not diagnostic.

TREATMENT

Once a diagnosis of Hirschsprung disease is confirmed, plans for surgical management are necessary. In patients presenting acutely ill with Hirschsprung’s-associated enterocolitis, fluid resuscitation, antibiotics, and rectal irrigation are indicated to stabilize the patient. Previously, patients underwent a multistage procedure. A temporary diverting ostomy was created first. Then when the child was older the aganglionic segment was resected and a coloanal anastamosis was performed. Some patients with enterocolitis, congenital anomalies, or other complications may still require an initial ostomy followed by a definitive repair at a later time. A laparoscopic single-stage endorectal pull-through procedure, however, is now the treatment of choice for most patients with Hirschsprung disease. Alternative approaches may be required for children with long-segment Hirschsprung disease and other less common forms of the disease.

SUGGESTED READINGS

1. Sreedharan R, Liacouras CA. Major symptoms and signs of digestive tract disorders. In: Kliegman RM, ed. Nelson Textbook of Pediatrics. 19th ed. Philadelphia: Saunders; 2011:1245-1247.

2. Constipation Guideline Committee of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition. Evaluation and treatment of constipation in infants and children: recommendations of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition. J Pediatr Gastroenterol Nutr. Sep 2006; 43(3):e1-e13.

3. Kenny SE, Tam PKH, Garcia-Barcelo M. Hirschsprung’s disease. Semin Pediatr Surg. 2010;19(3):194-200.

4. Amiel J, Sproat-Emison E, Garcia-Barcelo M, et al. Hirschsprung disease, associated syndromes and genetics: a review. Journal of Medical Genetics. January 1, 2008; 45(1):1-14.

5. Haricharan RN, Georgeson KE. Hirschsprung disease. Seminars in Pediatric Surgery. 2008;17(4):266-275.

6. Langer JC, Durrant AC, de la Torre L, et al. One-stage transanal soave pull-through for Hirschsprung disease: a multicenter experience with 141 children. Ann Surg. October 2003;238(4):569-576.

7. Coran AG, Teitelbaum DH. Recent advances in the management of Hirschsprung’s disease. Am J Surg. 2000; 180(5):382-387.

8. Jones KL. Smith’s Recognizable Patterns of Human Malformation. 6th ed. Philadelphia, PA: Saunders; 2005.

9. Fiorino K, Liacouras CA. Congenital aganglionic mega-colon (Hirschsprung disease). In: Kliegman RM, ed. Nelson Textbook of Pediatrics. 19th ed. Philadelphia: Saunders; 2011:1284-1287.