What is the appropriate evaluation and management for a 12-year-old girl presenting to the pediatric emergency room with abdominal pain that started in the right lower quadrant and radiates to the left, without emesis, fever, or issues with bowel or bladder function?

Evaluation of Abdominal Pain in a 12-Year-Old Girl with Right to Left Lower Quadrant Pain

Ultrasound should be the initial imaging study for this 12-year-old girl with right lower quadrant pain radiating to the left lower quadrant, as it avoids radiation exposure and has high sensitivity for gynecological and appendiceal pathology. 1

Key History Questions

Pain Characteristics

• Exact onset timing and progression of pain
• Pain migration pattern (especially from periumbilical to RLQ)
• Pain quality (sharp, crampy, constant, intermittent)
• Pain severity on a scale appropriate for age
• Aggravating/alleviating factors
• Previous similar episodes

Associated Symptoms

• Menstrual history (menarche, last menstrual period, regularity)
• Urinary symptoms (dysuria, frequency, hematuria)
• Gastrointestinal symptoms (anorexia, nausea, vomiting, diarrhea, constipation)
• Vaginal discharge or bleeding
• Weight loss or night sweats
• Recent illnesses

Past Medical History

• Previous abdominal surgeries
• Chronic medical conditions
• Recent viral illnesses (may cause temporary immune suppression) 2
• Previous episodes of similar pain
• Family history of inflammatory bowel disease, ovarian pathology

Physical Examination Focus

• Vital signs (absence of fever is notable but doesn't rule out serious pathology)
• Abdominal examination:
  • Location of tenderness (RLQ to LLQ radiation pattern)
  • Presence of rebound tenderness or guarding
  • Rovsing's sign (RLQ pain with LLQ palpation)
  • Psoas sign (pain with hip extension)
  • Obturator sign (pain with internal rotation of flexed hip)
• Pelvic examination (if appropriate based on age/development)
• Rectal examination if indicated

Diagnostic Investigations

Laboratory Tests

• Complete blood count with differential
• C-reactive protein and erythrocyte sedimentation rate
• Urinalysis to rule out urinary tract infection
• Pregnancy test (if menstruating)
• Liver function tests and amylase/lipase if indicated

Imaging Studies

1. Transabdominal and transvaginal (if appropriate) ultrasound

   • First-line imaging for suspected appendicitis in pediatric patients 1
   • Sensitivity 87-95% and specificity 85-98% for appendicitis 1
   • Excellent for evaluation of gynecologic pathology 3
   • Appendiceal diameter >6mm has sensitivity of 97.5% 1

2. CT abdomen and pelvis with IV contrast (if ultrasound is inconclusive)

   • Consider only if ultrasound is inconclusive or negative but clinical suspicion remains high 1
   • Higher sensitivity (90.8%) and specificity (94.2%) than ultrasound 4
   • Radiation exposure is a significant concern in pediatric patients

3. MRI abdomen and pelvis without IV contrast

   • Alternative to CT if ultrasound is inconclusive 1
   • Avoids radiation exposure
   • Excellent sensitivity (97%) and specificity (95%) for appendicitis 5
   • Limited by availability and cost

Key Differential Diagnoses to Consider

Gynecological Causes

• Ovarian torsion (requires immediate surgical intervention) 3
• Ovarian cyst (rupture, hemorrhage)
• Pelvic inflammatory disease
• Mittelschmerz (ovulation pain)
• Dysmenorrhea

Gastrointestinal Causes

• Appendicitis (most common surgical cause of abdominal pain in this age group)
• Mesenteric adenitis
• Inflammatory bowel disease
• Gastroenteritis (can coexist with appendicitis) 1

Urological Causes

• Urinary tract infection
• Renal calculi

Other Considerations

• Constipation
• Abdominal tuberculosis (consider if fever, weight loss, night sweats) 2
• Psoas abscess

Management Algorithm

1. Initial Assessment:

   • Stabilize if any concerning vital signs
   • Provide appropriate analgesia (do not withhold pain medication)
   • Obtain laboratory studies

2. Imaging Decision:

   • Proceed directly to ultrasound as first-line imaging 1
   • If ultrasound is inconclusive and clinical suspicion remains high:
     • Consider MRI if available (to avoid radiation)
     • CT with IV contrast if MRI unavailable or not feasible

3. Treatment Based on Findings:

   • Surgical consultation for appendicitis, ovarian torsion
   • Gynecological consultation for ovarian pathology
   • Medical management for non-surgical conditions

Important Considerations

• Do not delay analgesia due to concerns about masking symptoms - this is no longer considered valid practice 1
• Pain that migrates from right to left lower quadrant is unusual for appendicitis and raises suspicion for gynecological pathology
• Absence of fever and vomiting does not rule out serious pathology
• Children with appendicitis may have atypical presentations, especially younger children 1
• The combination of ultrasound and CT increases sensitivity to 99% but decreases specificity to 89% 1

Common Pitfalls to Avoid

• Attributing pain to constipation without adequate investigation
• Failing to consider gynecological causes in adolescent females
• Delaying imaging in patients with persistent pain
• Overlooking non-appendiceal causes of right lower quadrant pain 6
• Failing to reassess pain regularly and adjust management accordingly 1