What is the most appropriate step for a 9-year-old girl presenting with right lower quadrant abdominal pain, no nausea, no fever, and a normal white blood cell (WBC) count to avoid missing a diagnosis?

Management of 9-Year-Old Girl with Right Lower Quadrant Pain

Admit the patient for serial abdominal examinations and repeat laboratory testing, as discharging home would risk missing early appendicitis—a diagnosis that cannot be excluded based on normal WBC and absence of fever alone. 1

Why Discharge is Inappropriate

• Normal WBC and absence of fever are present in approximately 50% of patients with appendicitis and do not rule out the diagnosis. 1
• Classic symptoms (fever and leukocytosis) are unreliable markers, particularly in early appendicitis, making clinical assessment alone dangerously inadequate. 1
• Clinical determination of appendicitis is notoriously poor in children, with negative appendectomy rates as high as 25% when relying on clinical assessment alone, yet discharging a patient home based solely on these reassuring findings would risk missing early appendicitis or other serious pathology. 1

The Correct Approach: Observation with Serial Assessment

• The combination of imaging with clinical observation provides the highest diagnostic yield while minimizing unnecessary surgery. 1
• Serial abdominal examinations over 6-12 hours allow detection of evolving peritoneal signs that may not be present initially, as appendicitis can progress from early to advanced stages during observation. 1, 2
• Repeat laboratory testing (CBC, CRP if available) can reveal developing leukocytosis or inflammatory markers that support the diagnosis. 1

Imaging Should Be Obtained During Observation

• Abdominal ultrasound should be the initial imaging study due to lack of radiation exposure, with reasonable sensitivity (76-87%) and specificity (83-89%) for identifying appendicitis in children. 1
• Children typically have less body fat than adults, making ultrasound visualization easier and more reliable in this age group. 1
• If ultrasound is equivocal and clinical suspicion remains high after serial examinations, CT scan with IV contrast should be considered, offering higher sensitivity (90-94%) and specificity (94%). 1

Critical Pitfall to Avoid

• The absence of right lower quadrant tenderness makes appendicitis less likely but does not exclude it, as atypical presentations can occur in children. 1
• Relying on a single physical finding or laboratory value is insufficient to rule out appendicitis. 2
• The acute abdomen carries 2-12% mortality, with the figure rising for every elapsed hour until specific treatment is provided, making timely diagnosis critical. 3