Assessment of Human Allergic Diseases

The diagnosis of immediate-type hypersensitivity begins with a thorough clinical history. If objective symptoms of asthma, rhinitis, urticaria, or aeroallergen-, insect-, drug-, or food-induced localized or systemic reactions are detected, sensitization is confirmed by using in vivo tests (intradermal or epicutaneous skin test) and in vitro assays (immunoglobulin E antibody serology, basophil activation, or mediator release). Discordance between the clinical history and confirmatory test results can occur as a result of heterogeneous allergen preparations, assay design and performance variability, and differences in data analysis, positive threshold criteria, and interpretation methods. The allergen provocation challenge is considered the gold standard diagnostic test, but it is rarely used except in food allergy. Molecular allergology advances allow for component allergen use and supplementation of complex allergen extracts to enhance diagnostic test sensitivity and specificity. Finally, mast cell tryptase is discussed within the context of patient diagnosis and management.