What is the best management for a young girl presenting with right lower quadrant pain, no nausea or vomiting, no fever, and leukocytosis (elevated White Blood Cell (WBC) count)?

Management of Young Girl with Right Lower Quadrant Pain and Leukocytosis

The best management is C - CT abdomen and pelvis with IV contrast, as this patient requires definitive imaging to confirm or exclude appendicitis and identify alternative diagnoses, given the atypical presentation with isolated leukocytosis but absence of classic appendicitis features. 1

Clinical Context and Risk Stratification

This presentation is diagnostically challenging because:

• Leukocytosis alone has limited diagnostic power for appendicitis, with a positive likelihood ratio of only 2.47, meaning it increases probability modestly but cannot confirm the diagnosis 1
• Fever is absent in approximately 50% of appendicitis cases, so its absence does not exclude the diagnosis 2
• The absence of nausea/vomiting is atypical for appendicitis but does not rule it out, as clinical determination of appendicitis is notoriously poor with negative appendectomy rates as high as 25% when relying on clinical assessment alone 2

Why CT is the Appropriate Next Step

Diagnostic Performance

• CT abdomen and pelvis with IV contrast demonstrates 91-95% sensitivity and 94-98% specificity for diagnosing appendicitis 1, 2
• CT identifies alternative diagnoses in 23-45% of cases presenting with right lower quadrant pain, which is critical given this atypical presentation 2
• The combination of right lower quadrant pain with leukocytosis creates sufficient clinical suspicion to warrant definitive imaging rather than observation or discharge 1

Alternative Diagnoses to Consider

CT will effectively evaluate for:

• Appendicitis (including retrocecal or atypical locations) 1
• Ovarian pathology (torsion, cyst rupture, tubo-ovarian abscess) in a young female 1
• Mesenteric adenitis 1
• Inflammatory bowel disease 1
• Urinary tract pathology 1

Why Other Options Are Inappropriate

Option A (Discharge with Instructions) - INCORRECT

• Discharging based solely on absence of fever and nausea risks missing early appendicitis or other serious pathology 2
• The presence of leukocytosis indicates an inflammatory process requiring explanation 1
• NSAIDs for pain control can mask evolving symptoms and delay diagnosis 2

Option B (Admit and Repeat Labs in 6 Hours) - INCORRECT

• Serial laboratory testing without imaging does not improve diagnostic accuracy for appendicitis 1, 2
• This approach delays definitive diagnosis and appropriate treatment 2
• Observation alone is not appropriate when imaging can provide immediate diagnostic clarity 1

Option D (Open Appendectomy) - INCORRECT

• Proceeding directly to surgery without imaging confirmation results in negative appendectomy rates of 25% 2
• This patient lacks sufficient clinical certainty (no fever, no nausea/vomiting) to justify empiric surgery 1
• Modern surgical practice requires imaging confirmation except in cases of clear peritonitis 1

Imaging Protocol Specifics

For adolescent females, the recommended approach is: 1

• CT abdomen and pelvis with IV contrast (oral contrast may be added for bowel luminal visualization but is not mandatory) 1
• In younger children, ultrasound should be attempted first, but given the clinical uncertainty here and need for comprehensive evaluation, CT is more appropriate 2
• MRI may be considered if the patient is pregnant (96% sensitivity and specificity), but CT remains first-line in non-pregnant adolescents 1, 2

Critical Management Pitfalls to Avoid

• Do not rely on absence of fever to exclude appendicitis - fever is absent in 50% of cases 2
• Do not assume leukocytosis alone confirms appendicitis - many non-infectious causes exist including physiologic stress, medications, and inflammatory conditions 3, 4
• Do not delay imaging if symptoms persist or worsen during any observation period 2
• Ensure pregnancy testing is obtained before CT in all females of reproductive age to avoid missing ectopic pregnancy and to guide imaging choices 5

Post-Imaging Management Algorithm

If CT confirms appendicitis: 2

• Immediate surgical consultation
• IV antibiotics
• Proceed to appendectomy

If CT shows alternative diagnosis: 1, 2

• Treat accordingly based on specific findings
• Gynecologic consultation if ovarian pathology identified

If CT is negative/inconclusive: 2

• Discharge with mandatory 24-hour follow-up
• Clear return precautions for worsening symptoms
• Re-evaluation if symptoms persist