What is the appropriate emergency department workup for a 9-year-old male presenting with abdominal pain, no nausea, vomiting, fever, or diarrhea, with a soft abdomen and diffuse tenderness, but no right lower quadrant (RLQ) tenderness?

Emergency Department Workup for a 9-Year-Old Male with Abdominal Pain

The appropriate emergency department workup for a 9-year-old male with abdominal pain, soft abdomen, diffuse tenderness, and no RLQ tenderness should begin with abdominal ultrasound as the initial imaging study, followed by laboratory tests including complete blood count and urinalysis.

Initial Assessment

• Abdominal pain in children requires careful evaluation as the differential diagnosis is broad, including both medical and surgical causes 1, 2
• The absence of nausea, vomiting, fever, and diarrhea, along with diffuse tenderness but no specific RLQ tenderness makes appendicitis less likely but does not rule it out completely 2, 3
• The presentation of abdominal pain with diffuse tenderness but soft abdomen suggests a potentially less acute process, but still requires thorough evaluation 2

Diagnostic Imaging Approach

First-Line Imaging

• Abdominal ultrasound should be the initial imaging study for pediatric patients with abdominal pain due to its lack of radiation exposure, wide availability, and ability to identify multiple potential causes 1
• Ultrasound is particularly valuable in children as they typically have less body fat, making visualization of abdominal structures easier than in adults 1
• Ultrasound can identify appendicitis, intussusception, and other causes of abdominal pain with reasonable sensitivity (76-87%) and specificity (83-89%) 1

Second-Line Imaging

• If ultrasound results are equivocal or inconclusive and clinical suspicion remains high for a serious condition, CT scan with IV contrast should be considered 1
• CT scan offers higher sensitivity (90-94%) and specificity (94%) for diagnosing appendicitis and other causes of abdominal pain but exposes the child to ionizing radiation 1
• The decision to proceed to CT should be based on clinical judgment, ultrasound findings, and the child's clinical status 1

Laboratory Testing

• Complete blood count (CBC) to assess for leukocytosis, which may indicate infection or inflammation 1, 2
• Urinalysis to rule out urinary tract infection or nephrolithiasis as causes of abdominal pain 2, 3
• Consider C-reactive protein if available, as it may help assess the severity of inflammation 1
• Basic metabolic panel to evaluate for electrolyte abnormalities that may contribute to abdominal pain 1

Clinical Considerations

• The absence of RLQ tenderness makes appendicitis less likely but does not exclude it, as atypical presentations can occur in children 1
• Diffuse abdominal tenderness with a soft abdomen could indicate early appendicitis, gastroenteritis, constipation, mesenteric adenitis, or other conditions 4, 2
• The absence of fever, nausea, vomiting, and diarrhea reduces the likelihood of infectious gastroenteritis but does not rule out other infectious or inflammatory processes 2

Management Algorithm

1. Perform abdominal ultrasound as first-line imaging 1
2. Obtain CBC, urinalysis, and other laboratory tests concurrently 1, 2
3. If ultrasound is inconclusive and clinical suspicion remains high:
   • Consider CT scan with IV contrast for further evaluation 1
   • Consider surgical consultation if clinical picture suggests a surgical condition despite negative imaging 1, 3
4. If initial workup is negative but symptoms persist or worsen, consider serial examinations and reassessment 3

Pitfalls to Avoid

• Relying solely on the absence of classic symptoms (fever, vomiting, RLQ tenderness) to rule out appendicitis, as pediatric presentations can be atypical 1, 3
• Overreliance on a single imaging modality when clinical suspicion remains high 1, 3
• Delaying surgical consultation when clinical picture suggests a surgical abdomen despite equivocal imaging findings 1, 3
• Failing to consider less common causes of abdominal pain in children, such as intussusception, Meckel's diverticulum, or sigmoid volvulus 4, 5