Methodology of double-blind controlled food challenges for the diagnosis of food allergies. Review of the literature and experience of these tests inthe department of internal medicine, clinical immunology and allergology, in Nancy.

The diagnosis of food allergy is based on double-blind placebo controlled f ood challenges. A review of the literature describes the indications of the se tests, once the proof of sensitization has been made by prick-tests and RAST or epicutaneous reactions. The required elements prior to oral challen ges, the contraindications, the preparation and monitoring of patients, the equipment and personnel in charge of DBPCFC and the medical responsibility are reviewed. Technical aspects of food preparation include the storage, t he choice of the nature of foods to be tested, and the vehicles; the proced ures of incrementation of doses are detailed, as well as the issues concern ing the minimal starting dose and final dose. Symptoms and delays of onset, pitfalls and failures are analysed. Finally, the tendency to lighten proce dures in favour of simple blind oral challenges is discussed. (C) 2000 Edit ions scientifiques et medicales Elsevier SAS.