Food allergy diagnosis and oral food challenge — branching viva

Examiner: Opening question

Examiner: A 9-month-old boy with severe atopic dermatitis is referred to you for "food allergy testing" before introducing solids. His mother wants a comprehensive allergy panel. Take me through your approach. [1]

Model answer: [1]

My first step is to take a structured clinical history rather than order a panel. I need to know whether this child has had any acute reactions to foods already introduced — the six key elements are: what food, how much, when (timing from ingestion), what happened (specific symptoms by organ system), reproducibility, and cofactors such as exercise or illness. [1]

A broad food allergy panel without a supporting clinical history will generate false positives in approximately 30 to 50% of atopic children, because sensitisation without clinical allergy is common. Each false positive becomes a dietary restriction, a nutritional risk, and a psychological burden. So I would not order a panel — I would direct testing only to foods identified by the clinical history. [5][2]