What Do the Findings Reveal About the Cause of Emesis in a Young Boy?

Radiology Quiz

A 2-year-old boy is brought to the emergency department because of vomiting of 3 days duration. When the emesis first started, the child was brought to another hospital, where he received intravenous fluids and had some improvement in symptoms before being sent home. The parents report that the child had possible fever and no bowel movements in the past 3 days; he is unable to tolerate anything by mouth.

The child appears uncomfortable and is tachypneic; temperature is 39ºC (102.2ºF). Mucus membranes are dry. Abdomen is distended with diffuse tenderness but without guarding or rigidity. Bowel sounds are diminished.

The hemoglobin level is 13.8 g/dL and white blood cell (WBC) count is 16,800/µL. Results of urinalysis are normal.

Two views of the abdomen in supine and prone positions are shown.

To which diagnosis do the findings point?

A. Intussusception.
B. Mass in right lower quadrant with bowel obstruction.
C. Appendicitis.
D. Pneumatosis with pneumoperitoneum.
E. Malrotation with midgut volvulus.

(Answer and discussion on next page.)
Radiology Quiz
Answer: C, Appendicitis 
The radiographs show multiple air fluid levels without pneumatosis or pneumoperitoneum. There is relative paucity of gas in the pelvis and right lower quadrant. A 1-cm oval calcification is present in the right lower quadrant of abdomen. These findings are pathognomonic for appendicitis with an appendicolith and possible perforation.

Acute appendicitis is the most common cause for emergency abdominal surgery in children. It occurs infrequently in children aged between 1 and 4 years (1 to 2 cases per 10,000) and more frequently in older children (25 cases per 10,000). It is rare in infants. The condition is usually caused by obstruction secondary to either appendicolith or lymphoid hyperplasia. Classically, it presents with abdominal pain, fever, anorexia, and vomiting. However, the diagnosis can be challenging in infants and toddlers with an atypical presentation. Abdominal distension and vomiting may be the only signs in neonates. Patients with neurological impairment or immunosuppression also tend to have an atypical presentation. Atypical and nonspecific signs often lead to a delay in the diagnosis and increased risk of perforation.

Abdominal pain may be in the right lower quadrant, deep in the pelvis, or right upper quadrant, depending on the position and the length of the appendix. Vomiting usually follows pain; however, it may precede pain in infants and toddlers. Diarrhea may also be seen and may be the chief concern if the appendix is in the pelvis. When diarrhea and vomiting are the predominant symptoms, one should consider other common diagnoses, such as gastroenteritis. Abdominal tenderness may be diffuse in infants and toddlers and localized to the right lower quadrant in older children. Rebound tenderness and involuntary guarding are more commonly seen with perforation. Fever is usually low-grade unless appendicitis is complicated by perforation and abscess formation, in which case it may be high-grade.

An elevated WBC count, elevated C-reactive protein level, and pyuria on urinalysis may indicate the diagnosis but are nonspecific findings. In conjunction with the history and the physical examination findings, these laboratory studies are sufficient to make the diagnosis in the vast majority of children.

In equivocal cases, imaging modalities (abdominal radiographs or ultrasonograms) may be helpful. Ultrasonographic evaluation is important in patients with potential complications. In this child, intussusception, malrotation with midgut volvulus, and an abdominal mass were strongly suspected. An abdominal ultrasonogram showed multiple fluid-filled loops of bowel in the right flank and right lower quadrant with significant bowel wall thickening and 1-cm appendicolith with adjacent complex fluid collection; there was no evidence of intussusception or a mass. These findings indicated appendicitis with perforation and an abscess.

Preoperative management typically involves opioid analgesics, correction of electrolyte abnormalities from poor oral intake, and prophylactic antibiotics (commonly cefoxitin, piperacillin/tazobactam, or a combination of gentamicin and clindamycin/metronidazole). Before surgery, the child received intravenous fluids, analgesia, and amoxicillin/clavulanate, gentamicin, and metronidazole. He underwent emergent exploratory laparotomy with appendectomy and completed a 10-day course of intravenous antibiotics for complicated appendicitis.