Diagnosing peanut allergy with skin prick and specific IgE testing

Area of Science:

• Pediatric Allergy and Immunology
• Diagnostic Accuracy in Food Allergy

Background:

• Food allergy is a prevalent childhood condition.
• Diagnostic thresholds for skin prick tests (SPT) and specific IgE levels are debated.
• Limited challenge-based studies have evaluated the predictive value of SPT wheal size or specific IgE levels.

Purpose of the Study:

• To assess the predictive value of a skin prick test wheal ≥ 8 mm or serum specific IgE ≥ 15 kU A/L for clinical peanut allergy.
• To determine if these predictive values are generalizable across different pediatric populations.

Main Methods:

• Retrospective analysis of peanut/tree nut food challenges in children up to 16 years.
• Inclusion of subjects from tertiary allergy clinics and community birth cohorts.
• Logistic regression modeling to analyze SPT and specific IgE data against challenge outcomes.

Main Results:

• A skin prick test result ≥ 8 mm showed a 95% predictive value for clinical allergy.
• A specific IgE level ≥ 15 kU A/L demonstrated a 92% predictive value for clinical allergy.
• These predictive values remained consistent regardless of age, nut type, or referral source.

Conclusions:

• SPT wheal size ≥ 8 mm and specific IgE levels ≥ 15 kU A/L are highly predictive of clinical peanut allergy.
• These diagnostic cutoffs appear generalizable in children undergoing peanut allergy assessment.
• The findings support the utility of these thresholds in diagnosing childhood peanut allergy.