[Non allergic skin reactions of drugs (author's transl)]

Non allergic skin reactions are differentiated in the following way: overdose, idiosyncrasy, intolerance and side effects. An intoxication caused by an overdose of a drug may be initiated by an increased resorption through the skin (e. g. salicylic acid or the obsolete boric acid). An overdose of a drug often leads to coma and in many cases, if the patients are lying unattended (e. g. at home). ischemic skin reactions, such as blisters or necrosis occur at pressure areas. Intolerance is an undesirable reaction, produced by a normal therapeutic dose of the drug. Reactions of special interest are those imitating an anaphylactic reaction (type I), such as histamine liberation, complement activation or intolerance to analgetics, dyes or preserving agents. Idiosyncrasy summarizes reactions, which differs both qualitatively and quantitatively from the normal response to therapeutic dose of a drug. Additionaly these reactions are characterized by an underlying biochemical disturbance: drug-induced porphyric crisis in porphyria acuta intermittens, INH induced pellagra or drug-induced lupus erythematosus are discussed in this context in greater detail. Side effects of a drug is a misnomen, but this term cannot be done without. These undesired effects can be differentiated into obligatory effects as seen after cytostatic treatment in the form of alopecia; and possible reactions such as chloasmas after treatment with oral hormonal contraceptives. We assume that some of these side effects would belong to the category of idiosyncrasy or intolerance, if their pathogenesis were known.