Initial Workup and Management for Pediatric Abdominal Pain
For pediatric patients presenting with abdominal pain, ultrasound should be used as the initial imaging modality, with CT or MRI reserved for cases where ultrasound results are inconclusive or equivocal. 1, 2
Initial Clinical Assessment
Age-specific considerations:
- Infants/toddlers: Consider congenital anomalies, malrotation, hernias, Meckel diverticulum, or intussusception 3
- School-aged children: Focus on constipation, infectious causes (gastroenteritis, colitis, respiratory infections, UTIs) 3
- Female adolescents: Consider pelvic inflammatory disease, pregnancy, ruptured ovarian cysts, or ovarian torsion 3
Red flag symptoms/signs that increase likelihood of surgical cause:
- Fever
- Bilious vomiting
- Bloody diarrhea
- Absent bowel sounds
- Voluntary guarding
- Rigidity
- Rebound tenderness 3
Laboratory Evaluation
- Complete blood count (CBC)
- C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR)
- Urinalysis
- Pregnancy test in adolescent females 3
Note: CRP and WBC count alone are insufficient to discriminate urgent from non-urgent diagnoses 4
Imaging Approach
First-line imaging:
- Ultrasound is recommended as the initial imaging modality for children with suspected abdominal pain requiring imaging 1, 2
Second-line imaging (if ultrasound is inconclusive):
- CT with IV contrast or MRI without IV contrast 1, 2
- The Infectious Diseases Society of America suggests either CT or MRI as subsequent imaging when ultrasound results are negative, equivocal, or non-diagnostic 1
- MRI abdomen/pelvis without IV contrast has excellent sensitivity (97%) and specificity (95%) for appendicitis 2
- CT is more readily available but involves radiation exposure 1
- CT may be particularly useful when complications such as abscess or bowel obstruction are suspected 2
Special considerations for appendicitis:
- Appendicitis is the most common cause of acute abdominal pain requiring surgery 3
- Ultrasound diagnostic criteria include appendiceal diameter (6.5mm has 92% accuracy) 2
- Children under 3 years have high risk of perforation, with nearly 100% of cases presenting with perforation 2
Pain Management
- First-line: Oral acetaminophen (15 mg/kg/dose, max 1000 mg) or ibuprofen (10 mg/kg/dose, max 600 mg) 2
- For severe pain: IV morphine (0.05-0.1 mg/kg/dose) in small titrated doses 2
- Important: Do not delay analgesia due to concerns about masking symptoms - this is no longer considered valid practice 2
Management Based on Suspected Diagnosis
Non-urgent causes:
- Patients suspected of non-urgent diagnoses can be safely reevaluated the next day 4
- For constipation: Abdominal radiography can confirm diagnosis 3
Urgent causes:
- Appendicitis: Prompt surgical consultation; appendectomy should be performed within 24 hours of admission, ideally within 8 hours for complicated cases 2
- Intra-abdominal abscess: Broad-spectrum antibiotics should be initiated promptly 2
- Bowel obstruction: Surgical consultation and abdominal radiography 3
Common Pitfalls to Avoid
Delayed diagnosis in young children: Children under 5 years have higher risk of perforation due to delayed diagnosis 2
Mistaking appendicitis for gastroenteritis: Five key predictors help distinguish appendicitis from gastroenteritis: vomiting, right lower quadrant pain, stool occult blood, elevated WBC count, and elevated CRP 2
Overreliance on conventional radiography: There is limited value for conventional radiography in acute abdominal pain workup except for diagnosing constipation or obstruction 4
Underdosing pain medication: Providing adequate analgesia is essential and does not interfere with diagnostic accuracy 2
Failing to consider recurrence: Abdominal pain is a common recurring problem in pediatric patients, with approximately 38% of children returning to emergency departments with similar complaints 5