CHRISTINA L. MASTER
HISTORY OF PRESENT ILLNESS
The patient is a 2-month-old boy who presents with vomiting and diarrhea. The patient had been recently discharged from the hospital 3 days ago. During that previous hospitalization, he had been diagnosed with gastroesophageal reflux by pH probe and upper gastrointestinal series. He had been discharged to home on ranitidine and had been doing well until the evening prior to presentation when he developed vomiting and diarrhea. He had 12 episodes of nonbloody, nonbilious vomiting with eight episodes of loose stools. There was no fever or associated upper respiratory symptoms. He had normal urine output. His mother reports that he was more fussy than usual and she noted a lump in his groin on the day of presentation to the hospital.
The patient was a full-term baby with an uncomplicated pregnancy, labor, and delivery history. He was hospitalized only once, diagnosed with gastroesophageal reflux, and placed on ranitidine.
T 36.9°C; RR 32/min; HR 136 bpm; BP 100/54 mmHg
Weight 5th percentile
On examination, the infant was alert and in no acute distress. His head, neck, cardiac, and respiratory examination were unremarkable. He was well hydrated with a nontender and non-distended, soft abdomen. There was no hepatosplenomegaly or abdominal masses. He had normal male genitalia, with bilaterally descended testicles. A tender, firm, and erythematous mass measuring 5 cm × 3 cm was palpable in the right inguinal region.
The complete blood count revealed a WBC count of 10 100 cells/mm3 (11% segmented neutrophils, 76% lymphocytes), a hemoglobin of 10.8 g/dL with a mean corpuscular volume of 87 fL and a platelet count of 387 000 mm3. Serum electrolytes, blood urea nitrogen, and creatinine were normal.
COURSE OF ILLNESS
An abdominal radiograph obtained on his previous admission suggested a cause for the current complaint (Figure 17-1). A surgical consultation was requested.
FIGURE 17-1. Abdominal radiograph.
DISCUSSION CASE 17-1
In this case, diarrhea was associated with vomiting and a critical physical finding, that of an inguinal mass. This essential finding directs the differential diagnosis toward causes of inguinal or scrotal swelling. An important distinction to make is between a painful or painless mass. A hydrocele is a common entity that causes painless inguinal or scrotal swelling. It is primarily differentiated from an inguinal hernia by the ability to palpate above the mass, revealing discontinuity between the mass and the inguinal canal. The mass, as a result, does not change in size with straining or crying. In addition, a hydrocele is not reducible and usually transilluminates, although the ability to transilluminate the mass does not exclude the possibility of an incarcerated hernia.
Another cause of a painful scrotal mass is testicular torsion. There often is no history of a prior scrotal mass, and in fact may be associated with a history of undescended testis. This mass is very tender and does not extend into the inguinal canal.
Torsion of the appendix testis results in a painful scrotal mass that may present as a tender blue nodule on the upper pole of the testis which, itself, is not tender. Inguinal lymphadenopathy may be tender or painless but the key to diagnosis is the lateral and inferior location of these nodes in relation to the inguinal canal. Signs of infection in the area of lymphatic drainage are also important in making this diagnosis. An inguinal hernia is usually characterized by a painless swelling in the inguinal area often increasing in size with crying or straining. Incarceration of the hernia results in extreme pain and signs of bowel obstruction. If strangulation occurs, bloody diarrhea may occur.
A thorough history and physical examination are the keys to this diagnosis. In this case, the painful nature and inguinal location of this mass are the essential findings. Abdominal radiograph from the previous admission revealed a right inguinal hernia (Figure 17-1, arrow) that is now incarcerated. The diagnosis is incarcerated inguinal hernia. The hernia was reduced in the emergency department by pediatric surgical staff. No hernia was noted on the left side on physical examination. The patient was admitted for intravenous fluids and observation to allow the bowel edema from the incarceration to resolve. The patient manifested no signs or symptoms of bowel necrosis during 2 days in the hospital after which he was taken to the operating room. Intraoperatively, bilateral inguinal hernias were found and repaired without any complications.
INCIDENCE AND EPIDEMIOLOGY OF INGUINAL HERNIA
The incidence of inguinal hernia is estimated to be anywhere from 1% to 5%, which is approximately 10-20 per 1000 live births. The incidence in premature infants is significantly higher, approaching 30%. The ratio of boys to girls is 6:1. In boys, the right side is more frequently involved than the left, presumably due to the embryologic origin of inguinal hernias through a patent processus vaginalis and the fact that the right testis descends later during gestation than the left. In both boys and girls, 60% of inguinal hernias occur on the right, 30% on the left, and 10% bilaterally. Inguinal hernias are usually diagnosed during the first year of life, most frequently in the first month of life. There is often a family history of inguinal hernia. Undescended testes may also be associated with inguinal hernias. Other conditions associated with inguinal hernias include Ehlers-Danlos syndrome, cystic fibrosis, congenital cytomegalovirus infection, and testicular feminization. There is no apparent ethnic or racial predisposition to inguinal hernia. Incarcerated inguinal hernias occur most frequently in those younger than 6 months of age, are less common after 2 years of age, and are rare after 5 years of age.
CLINICAL PRESENTATION OF INGUINAL HERNIA
An inguinal hernia usually presents as an asymptomatic swelling in the scrotal or labial area that increases in size with any increase in intra-abdominal pressure, as occurs with crying or straining. Reducible hernias disappear spontaneously or with minimal pressure. An incarcerated hernia develops when a loop of bowel becomes trapped and is accompanied by severe pain and signs of bowel obstruction, such as bilious emesis. Strangulation of the herniated loop of bowel occurs when the blood supply to the bowel is compromised and may develop within 2 hours of incarceration. Urgent medical attention is necessary in cases of incarceration and emergency surgical intervention may be necessary in cases of strangulation.
The key to diagnosis of inguinal hernia lies in the index of suspicion in the appropriate historical context, which is then confirmed by physical examination. In distinguishing an incarcerated hernia, an awareness of the other important entities in the differential diagnosis is important. The diagnosis itself is primarily founded on the history and physical examination as well as a thorough knowledge of the disease process.
Abdominal radiograph. An abdominal radiograph may show signs of bowel obstruction and may serve as an adjunctive supportive piece of evidence in making the diagnosis.
In cases of incarcerated hernia, time is of the essence. Compromised blood flow to the affected loop of bowel may result in strangulation and bowel necrosis within 2 hours, hence medical intervention is necessary. Attempt at reduction of the incarcerated hernia by experienced pediatric surgical staff is optimal. A gentle attempt at reduction using pressure on the scrotum with simultaneous counterpressure above the external inguinal ring is indicated, but should never be forcefully done. Intravenous hydration and nasogastric tube decompression, in anticipation of definitive surgical management, is also indicated. Immediate surgical correction is necessary if the incarcerated hernia is not reducible. If the incarcerated loop of bowel is reduced, surgery may be postponed for 12-36 h to allow the bowel edema to resolve.
Elective repair of an asymptomatic inguinal hernia should be performed as soon as possible after diagnosis to avoid complications, such as incarceration. All inguinal hernias require surgical correction as they do not resolve spontaneously. In boys, undescended testes may be associated with inguinal hernia and require orchiopexy. There is still ongoing debate as to the importance of surgical exploration of the contralateral side in search of an occult inguinal hernia not detected by physical examination, as did occur with the patient in this case. This decision is left to the individual surgeon, but contralateral exploration is performed in the majority of cases.
1. Clarke S. Pediatric inguinal hernia and hydrocele: an evidence based review in the era of minimal access surgery. J Laparoendosc Adv Surg Tech A. 2010;20(3):30-39.
2. Brandt ML. Pediatric hernias. Surg Clin North Am. 2008;88(1):27-43, vii-viii.
3. Katz D. Evaluation and management of inguinal and umbilical hernias. Pediatr Ann. 2001;30:729-735.
4. Kapur P, Caty M, Glick P. Pediatric hernias and hydroceles. Pediatr Clin North Am. 1998;45:773-789.
5. Irish M, Pearl R, Caty M, Glick P. The approach to common abdominal diagnoses in infants and children. Pediatr Clin North Am. 1998;45:729-772.