When to use molecular allergens and how to interpret their level in food allergy

Natural molecular allergens (present in extracts and purified from allergenic source materials) or recombinant allergens (produced by genetic engineering) are used more and more frequently in the diagnosis of food allergy. If diagnosis is still mainly clinically-based, additional tests are often necessary: prick tests with an extract or with raw food, and assays for IgE antibodies specific for the allergen source and for molecular allergens. The latter are not available for all foods and for many allergenic components of the same foods. They are a valuable aid for the differentiation of food allergy from a simple sensitization, for evaluation of the severity and the risk of persistence of the allergy, and for deciding whether or not to do an oral allergen challenge test. They are especially useful for cow's milk, peanut, hen's egg, wheat, shellfish and fish allergies. (C) 2012 Published by Elsevier Masson SAS.