Immunology and allergy--the twins.

The sciences of immunology and allergology have common roots and could be considered as twins. Historical highlights in discoveries of allergic and immunologic phenomena are mentioned and the IgE-mediated allergic reaction is described as a form of immunologic processes. The knowledge in basic and clinical immunology as well as in experimental and applied allergology has grown enormously in the last two decades and the possibilities of making the best of the immense amount of new information are discussed (basic and post-graduate training, journals on immunology and allergology, attendance at congresses).