Rational diagnostics of food allergies

In case of suggested IgE-mediated food allergies the anamnesis will lead to a working diagnosis, facilitate further diagnostic planning, and serve as basis for interpretation of the tests. Combined allergic signs are more indicative for systemic IgE reactions than isolated organ symptoms (i.e.; gastrointestinal tract). Exceptions are (isolated) oropharyngeal allergy-like symptoms due to watersoluable (in part labile) food allergens. Sensitization tests detect the presence of allergen-specific IgE to food allergens directly (in serum) or indirectly (i.e.; in skin Prick tests). Ideally, they are qualitatively concordant, but not necessarily quantitatively associated. Selected use of single allergens (components) for IgE-testing can increase test sensitivity and improve analytical specificity, providing risk-associated allergens, indicators for cross-reactivity, and markers for primary sensitizations. Positive test results are only clinically relevant in case of corresponding symptoms upon exposure. In case of doubt oral challenge tests will help to firmly establish or rule out a diagnosis of food allergy.