[Allergic diseases. Current developments and problems].

Atopic diseases are the manifestations of the allergic reaction type I according to Gell and Coombs. The most important step was the identification of IgE as the decisive cause. The most important progresses during the last 5 years were the identification of an IgE-mediated delayed reaction by secondary target cells--besides mast cells and basophils, the proof that similar biochemical reactions can be induced by non-immunologic causes (parallergic reactions). These are the underlying mechanisms in intolerance of analgesics, and contrast media as well as anaphylactoid reactions after infusion of plasma substituents, first exact data on the determination of the high production of IgE, the specific sensitization, and the special manifestation by genetic factors. The international research is particularly concentrated on the identification of allergens and the improvement of immunotherapy.