[Pseudoallergic reactions to drugs].

A lot of substances currently used in medicine and daily life are found to induce pseudoallergic reactions. Because of practical importance intolerance to aspirin and additives as well as anaphylactoid reactions to sulfites and local anaesthetics are presented. The aetiopathological problems are not yet solved, and the differentiation from true allergic diseases is difficult. Concerning the local anaesthetics, additional side effects of other components of the solutions have to be considered. An accurate history is often worthy. Generally, it is not possible to clear up pseudoallergic reactions through skin tests, so that incremental challenge is necessary.