What is the best course of action for a 9-year-old female patient with right lower quadrant pain, normal white blood cell (WBC) count, no fever, no anorexia, and no rebound tenderness, suspected of having appendicitis?

Management of Low-Risk Suspected Appendicitis in a 9-Year-Old Girl

Discharge the patient with clear return precautions and mandatory 24-hour follow-up. 1

This 9-year-old presents with a low-risk clinical picture that does not warrant immediate imaging or admission. The absence of fever, anorexia, rebound tenderness, and normal WBC count (9,000/mm³) significantly reduces the probability of acute appendicitis, though it does not completely exclude it. 2, 1

Risk Stratification Analysis

This patient's clinical profile places her in the low-risk category:

• Normal WBC count (9,000/mm³): When both WBC and CRP are normal, acute appendicitis is very unlikely, with a negative predictive value of 98.8-100% 3, 4
• Absence of fever: Fever is present in only approximately 50% of appendicitis cases, but its absence combined with other negative findings is significant 1, 5
• No anorexia: The absence of anorexia is a strong discriminator against appendicitis 1, 5
• No rebound tenderness: This indicates absence of peritoneal irritation, a key finding in established appendicitis 2, 1

In pediatric patients, the combination of fever >38°C, WBC ≥10,100/mm³, and rebound tenderness creates a prediction rule with only 1% missed appendicitis rate—this patient has none of these three critical findings. 2

Why Not CT Imaging (Option B)?

CT is not indicated for low-risk patients and exposes children to unnecessary radiation without changing management. 1

• Clinical scoring systems should guide imaging decisions, not reflexive CT ordering 1
• In children with low clinical suspicion, CT exposes patients to unnecessary radiation without changing management 1
• The American College of Radiology recommends a step-up approach tailored to clinical risk stratification, reserving CT for intermediate or high-risk patients 1
• Low-risk patients (based on clinical assessment) can be safely discharged with appropriate safety netting, avoiding unnecessary imaging and radiation exposure 1

Why Not Admission with 24-Hour Observation (Option A)?

Admission with 24-hour observation is not indicated for low-risk patients—it is resource-intensive and exposes the patient to unnecessary hospitalization costs and risks. 1

• The WSES Jerusalem Guidelines specifically recommend against admission for low-risk patients who can be safely discharged with return precautions 1
• This approach would be appropriate for intermediate-risk patients with equivocal findings, but not for this clearly low-risk presentation 1

Recommended Discharge Protocol

Discharge with the following specific instructions:

1. Return immediately if any of these develop:

   • Fever (temperature >38°C) 2, 1
   • Persistent vomiting 1
   • Development of rebound tenderness or guarding 2, 1
   • Worsening or migrating pain to the right lower quadrant 1, 5
   • Inability to tolerate oral intake 1

2. Mandatory 24-hour follow-up: This is essential due to measurable false-negative rates in low-risk presentations 1

3. At follow-up, if symptoms persist or worsen: Proceed to imaging with ultrasound as first-line in pediatrics, followed by CT if ultrasound is inconclusive 2, 1

Critical Clinical Pitfall to Avoid

Do not rely solely on absence of fever and normal WBC to completely exclude appendicitis. While these findings significantly reduce probability, early appendicitis can present with atypical features. 1, 5 The key is ensuring reliable follow-up and clear return precautions, as approximately 8.4% of patients with appendicitis may have low clinical scores initially. 6

The combination of normal WBC with absence of classic symptoms provides a negative predictive value of 95.6-98.2% for excluding appendicitis in pediatric patients, making safe discharge with close follow-up the most appropriate management. 7, 4