What are the symptoms of appendicitis in children?

Symptoms of Appendicitis in Children

Children with appendicitis most commonly present with abdominal pain, vomiting, and fever, though the presentation is frequently atypical, particularly in younger children under 5 years of age. 1, 2, 3

Classic Presentation (Present in ~50% of Cases)

The "classic" triad includes 4:

• Periumbilical pain migrating to the right lower quadrant (increases likelihood 1.9-3.1 times) 5
• Anorexia, nausea, or vomiting 4, 6
• Fever and leukocytosis 4

However, this classic presentation occurs in only approximately 50% of pediatric patients, making diagnosis challenging 4.

Most Common Presenting Symptoms

In order of frequency 6, 5:

• Vomiting (present in nearly all cases in young children) 6
• Fever (most useful single sign; increases likelihood 3.4 times when present, decreases likelihood significantly when absent with LR 0.32) 5
• Abdominal pain (though may not localize to right lower quadrant initially) 6, 5
• Anorexia/loss of appetite 6, 5
• Diarrhea (present in approximately 40% of young children) 6

Most Common Physical Examination Findings

• Abdominal tenderness (present in nearly all cases) 6
• Rebound tenderness (triples the odds of appendicitis when present with LR 3.0; its absence reduces likelihood with LR 0.28) 5
• Peritonitis (especially common in younger children due to delayed diagnosis) 6
• Fever ≥38°C 6, 5
• Abdominal distension (particularly in perforated cases) 6

Critical Age-Specific Considerations

Children under 5 years present with atypical symptoms significantly more frequently than older children, making diagnosis particularly unreliable in this age group. 1, 2, 3

Atypical Features Are Common

44% of children with proven appendicitis present with six or more atypical features, with a median of five atypical characteristics 7. The most common atypical presentations include 7:

• Absence of fever (83% of cases)
• Absence of Rovsing's sign (68%)
• Normal or increased bowel sounds (64%)
• Absence of rebound pain (52%)
• No migration of pain (50%)
• Lack of guarding (47%)
• Abrupt onset rather than gradual pain (45%)
• Lack of anorexia (40%)
• Pain not maximal in right lower quadrant (32%)

Young Children (<3-5 Years) Specific Features

In children under 3 years 6:

• 100% present with perforated appendicitis due to diagnostic delays
• Average symptom duration of 3 days before diagnosis
• Frequently misdiagnosed initially as upper respiratory infection, otitis media, or urinary tract infection (14 of 18 children in one series)
• Diffuse rather than localized tenderness is common
• Small bowel obstruction findings on imaging in over 50% of cases

Laboratory Findings

White blood cell count and absolute neutrophil count are the strongest negative predictors when normal 5, 7:

• WBC <10,000/mm³ decreases likelihood dramatically (LR 0.18-0.22) 5, 7
• Absolute neutrophil count ≤6,750-7,500/mm³ strongly argues against appendicitis (LR 0.06-0.35) 4, 5, 7
• Leukocytosis (>12,000/mm³) is present in approximately 67% of cases 6

Critical Diagnostic Pitfalls

Do not dismiss appendicitis in young children despite atypical presentations, as delayed diagnosis leads to perforation rates approaching 100% in children under 3 years 2, 6. The average delay is 3-5 days, often because children are initially treated for other conditions 6.

The absence of right lower quadrant pain does not exclude appendicitis, as 32% of children with proven appendicitis do not have maximal pain in this location 7.

Clinical scoring systems help but cannot eliminate the need for imaging, particularly in young children where atypical presentations predominate 1, 2, 3.

Diagnostic Algorithm

When appendicitis is suspected 1, 3:

1. Obtain urinalysis to exclude urinary tract infection (essential first step) 1, 3
2. Check WBC and absolute neutrophil count (strongest negative predictors when normal) 5, 7
3. Perform ultrasound as initial imaging (no radiation, can identify alternative diagnoses) 1, 2, 3
4. If ultrasound is equivocal or non-diagnostic and clinical suspicion persists, proceed directly to CT with IV contrast or MRI rather than repeating ultrasound 1, 2, 3