Food Allergy Testing in Atopic Dermatitis: A Purpose-First Comparison of International Guidelines

Food allergy testing is frequently requested in atopic dermatitis (AD), yet international guidance appears inconsistent. We performed a structured narrative review of major guidelines, practice parameters, and society statements from North America, Europe, the United Kingdom, and East Asia, current through August 23, 2026. Recommendations were compared by clinical purpose, treatment-response condition, test modality, and intended consequence. The apparent conflict largely reflects three questions being combined: diagnosis of a suspected immediate immunoglobulin E (IgE)-mediated reaction, safe introduction of an allergenic food, and investigation of food as a driver of eczema. Across documents, testing is history-directed and indiscriminate panels are discouraged. For eczema-trigger investigation, NIAID, NICE, Japanese, and Korean guidance uses a treatment-response gate; the AAAAI 2022 work group requires optimal skin care before additional testing, while EuroGuiDerm version 4.0 limits testing for suspected food-triggered eczema to moderate-to-severe disease with a supporting history or suspicion. Prevention guidance differs on pre-introduction peanut screening but agrees on timely introduction. The 2023 Joint Task Force recommendation addresses elimination diets as treatment, not a diagnostic threshold. Positive skin prick testing or food-specific IgE indicates sensitization, not clinical allergy; automatic elimination may cause nutritional harm and loss of oral tolerance. A purpose-first pathway reconciles most apparent conflict and supports clinical confirmation before long-term avoidance.