Appendicitis (peds)

Background

• Most common between 9-12yr
• Perforation rate 90% in children <4yr
• NPV of 98% achieved if:
  • Lack of nausea (or emesis or anorexia)
  • Lack of maximal TTP in the RLQ
  • Lack of neutrophil count > 6750

Diagnosis

• Local tenderness + McBurney's point rigidity most reliable clinical sign

Neonates

• History
  • Vomiting
  • Irritability/lethargy
• Physical
  • Abdominal distention

Infants (30 days - 2 yrs)

• History
  • Vomiting
  • Abdominal pain
  • Fever
• Physical
  • Diffuse abdominal tenderness
    • Localized RLQ TTP occurs <50%

Preschool (2 - 5yrs)

• History
  • Vomiting (often precedes pain)
  • Abdominal pain
  • Fever
• Physical
  • RLQ tenderness

School-age (6 - 12yrs)

• History
  • Vomiting
  • Abdominal pain
  • Fever
• Physical
  • RLQ tenderness

Adolescents (>12yrs)

• Present similar to adults
  • RLQ pain
  • Vomiting (occurs after onset of abdominal pain)
  • Anorexia

Laboratory Findings

• WBC or neutrophil% elevation
  • Sn/Sp = 79/80%
  • May also be seen in gastroenteritis, strep, PNA, PID
• CRP
  • May be more Sn than WBC in identifying perforation
    • Consider in pts with a prolonged history
• UA
  • 7-25% of pts with appy have sterile pyuria

Imaging

• Consider only in intermediate-risk pts
• Ultrasound
  • Sn: 88%, Sp: 94%
  • Consider as 1st choice in non-obese children
• CT (+/- contrast)
  • Sn: 94%, Sp: 95%
  • Consider if U/S is equivocal OR strong suspicion despite normal U/S

Pediatric Appendicitis Score

• Anorexia - 1pt
• Nausea or vomiting - 1pt
• Migration of pain - 1pt
• Fever > 100.5 - 1pt
• Pain with cough, percussion, or hopping - 2pt
• RLQ tenderness - 2pt
• WBC > 10K - 1pt
• Neutrophils + bands > 7500- 1pt

• Score ≤ 2
  • Low risk (0-2.5%)
  • Consider d/c home with close f/u
• Score ≥ 7
  • High risk
  • Consider surgical consultation
• Score 3-6
  • Indeterminate risk
  • Consider serial exams, consultation, or imaging

Management

• Fluids (20 mL/kg boluses)
• Analgesia
• ABx
  • Second gen cephalosporin OR
  • Piperacillin/tazobactam OR
  • Penicillin allergy?
    • Gent + (clinda or metronidazole)

Differential Diagnosis

• Emergent surgical diagnoses
  • Bowel obstruction
  • Malrotation
  • Intussusception
  • Ovarian torsion
  • Ectopic pregnancy
• Emergent nonsurgical diagnoses
  • HUS
  • DKA
• Non-emergent diagnoses
  • PID
  • PNA
  • UTI
  • Strep throat
  • Gastroenteritis (esp yersinia)

See Also

Peds: Abdominal Pain

Source

Bundy DG et al. Does this child have appendicitis? JAMA 2007; 298:438-451, UpToDate