What scoring system is used to diagnose appendicitis in adults and pediatric patients presenting with abdominal pain?

Scoring Systems for Appendicitis Diagnosis

Adults

The AIR (Appendicitis Inflammatory Response) score and AAS (Adult Appendicitis Score) are the recommended clinical scoring systems for diagnosing appendicitis in adults, while the Alvarado score should only be used to exclude appendicitis, not to confirm it. 1

Recommended Scoring Systems for Adults

• AIR Score and AAS Score are the best performing clinical prediction scores with the highest discriminating power in adults with suspected acute appendicitis 1
• These scores decrease negative appendectomy rates in low-risk groups and reduce the need for imaging studies and hospital admissions in both low- and intermediate-risk groups 1
• The 2020 WSES Jerusalem Guidelines provide a strong recommendation (1A) for using AIR and AAS scores as clinical predictors 1

Alvarado Score Limitations in Adults

• The Alvarado score is not sufficiently specific for diagnosing acute appendicitis in adults and should be used only to exclude the diagnosis 1, 2
• A score <5 can effectively rule out appendicitis with 99% sensitivity 2, 3
• The score is unreliable in differentiating complicated from uncomplicated appendicitis in elderly patients and is less sensitive in HIV-positive patients 1
• Guidelines suggest against using the Alvarado score to positively confirm clinical suspicion of acute appendicitis in adults (Weak recommendation, 2B) 1

Risk Stratification Algorithm for Adults

• Low-risk patients (Alvarado <5, low AIR/AAS scores): Clinical scores are sufficiently sensitive to exclude appendicitis; imaging may not be needed 1, 2
• Intermediate-risk patients (Alvarado 5-6): Require imaging diagnostics, preferably ultrasound followed by CT if inconclusive 1, 4
• High-risk patients (Alvarado ≥7, high AIR/AAS scores): Proceed to surgical consultation; CT may be used to assess for perforation/complications 2, 5

Pediatric Patients

In pediatric patients, the Pediatric Appendicitis Score (PAS) and AIR score are useful for risk stratification, but diagnosis should not be based on clinical scores alone. 1

Recommended Scoring Systems for Children

• Pediatric Appendicitis Score (PAS) includes right lower quadrant pain with coughing, hopping, or percussion—a sign particularly relevant in children 1, 4
• AIR Score has the highest discriminating power and outperforms both Alvarado and PAS in predicting appendicitis in children 1
• Pediatric Appendicitis Laboratory Score (PALabS) includes clinical signs, leukocyte and neutrophil counts, CRP, and calprotectin; a score ≤6 has 99.2% sensitivity and 97.6% negative predictive value 1

Key Guideline Recommendations for Pediatrics

• Guidelines suggest against making a diagnosis based on clinical scores alone in pediatric patients (Weak recommendation, 2C) 1
• Laboratory tests and serum inflammatory biomarkers (WBC, CRP) should be routinely requested in children with suspected appendicitis (Strong recommendation, 1D) 1
• Both biomarker tests and scores should be adopted to predict severity of inflammation and need for imaging (Weak recommendation, 2D) 1

Pediatric Risk Stratification Algorithm

• Low-risk patients (PAS <3, PALabS ≤6): Can be safely managed with close observation; imaging may not be needed 1
• Intermediate-risk patients (PAS 4-7, Alvarado 4-6): Ultrasound is the initial imaging modality of choice with 93% accuracy, 86% sensitivity, and 97% specificity 1
• High-risk patients (PAS ≥8): At cutoff ≥8, PAS shows 89% specificity for adolescent females; proceed to imaging or surgical consultation 1

Special Considerations in Children

• Preschool-age children often present with atypical features, more rapid progression, and higher incidence of complications, resulting in lower PAS and Alvarado scores than school-aged children 1
• CRP level ≥10 mg/L and leukocytosis ≥16,000/mL are strong predictive factors for appendicitis in pediatric patients 1

Elderly Patients (≥65 years)

In elderly patients, the Alvarado score can be used to exclude appendicitis but not to diagnose it, and clinical scores should always be combined with imaging due to atypical presentations. 1

Specific Recommendations for Elderly

• Scoring systems are suggested for excluding acute appendicitis in elderly patients with low-probability scores (Conditional recommendation, low quality evidence) 1
• Guidelines suggest against basing the diagnosis solely on scoring systems in elderly patients (Conditional recommendation, low quality evidence) 1
• Alvarado scores of 5-10 should correspond to high risk of appendicitis in the elderly, with 86.6% of confirmed cases scoring 5-8 1

Common Pitfalls to Avoid

• Do not use Alvarado score alone to confirm appendicitis in any age group—it lacks sufficient specificity 1, 2
• Do not skip imaging in intermediate-risk patients—these patients have only 29-36% probability of appendicitis and require diagnostic confirmation 1, 5
• Do not rely on clinical scores alone in pregnant patients—laboratory tests and inflammatory parameters should always be requested 1
• Recognize atypical presentations in elderly patients, young children, and pregnant women where scores may underperform 1