Allergen molecules (synonyms: single allergens, al-lergen components) open up new horizons for the targeted allergen-specic diagnostics of immuno-globulin E (IgE) in singleplex determination. e following rationales support the targeted use of al-lergen molecules and, more importantly, improve test properties: (1) increased test sensitivity (“analyticalsensitivity”), particularly when important allergens are under-represented or lacking in the extract; (2) improved test selectivity (analytical specicity), particularly when the selected IgE rep-ertoire against an allergen yields additional infor-mation on: (a) potential risk, (b) possible cross-reactivity, or (c) primary (species-specic) sensitiza-tion. However, the appropriate indication for the use of single allergens can only be established on a case-by-case basis (depending on the clinical context and previous history) and in an aller-gen-specic manner (depending on the allergen source and the single allergens available), rather than in a standardized way. Numerous investigations on suspected food aller-gy, insect venom allergy, or sensitization to respi-ratory allergens have meanwhile demonstrated the successful use of dened molecules for aller-gen-specic singleplex IgE diagnosis. Specic IgE to single allergens is limited in its suitability to pre-dict the clinical relevance of sensitivity on an in-dividual basis. In food allergies, one can at best identify the relative risk of a clinical reaction on the basis of an IgE prole, but no absolutely reli-able prediction on (future) tolerance can be made. Ultimately, the clinical relevance of all IgE nd-ings depends on the presence of corresponding symptoms and can only be assessed on an individ-ual basis (previous history, symptom log, and prov-ocation testing with the relevant allergen source
where appropriate). us, also in molecular aller-gology, the treating physician and not the test re-sult should determine the clinical relevance of di-agnostic ndings