Appendicitis in the Infant Population: A Case Report and Review of a Four-Month Old With Appendicitis.

<p><b>BACKGROUND: </b>Appendicitis is uncommon in children &lt;6&nbsp;months old, with few observational studies reporting cases of children younger than 5&nbsp;years old with the diagnosis. The classic periumbilical pain that migrates to the right lower quadrant, followed by the onset of fever and vomiting, is present in approximately 40% of pediatric patients under 12&nbsp;years of age with appendicitis.</p><p><b>CASE REPORT: </b>A 4-month-old girl presented to the Emergency Department (ED) with acute onset of grunting, pallor, fussiness, emesis, and diarrhea. The patient was initially afebrile, tachycardic, and tachypneic with a soft, nondistended, nontender abdomen and active bowel sounds. The patient became febrile, with a maximum temperature of 39.3&deg;C (102.7&deg;F), and remained tachycardic despite receiving fluids and antipyretics. Laboratory studies were notable for mild dehydration and sterile pyuria. Chest x-ray study was negative for infectious etiologies. Initial abdominal ultrasound found no clear etiology of the patient&#39;s symptoms. The patient was admitted to inpatient pediatrics for dehydration, fever, and presumed pyelonephritis. Twenty-four hours later the patient&#39;s abdomen became distended and diffusely tender to palpation, with obstipation and increasing episodes of emesis. Abdominal x-ray study demonstrated mild gaseous distension of multiple bowel loops with repeat abdominal ultrasound notable for a focal 8-mm, noncompressible hyperemic structure in the right lower quadrant. The patient was taken to the operating room for a laparoscopic appendectomy. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Appendicitis is a potentially life-threatening condition. In the infant population it frequently presents without the features typically seen in older children.</p>