Risk factors for drug allergy.

Judging from available data on penicillin allergy there appear to be multiple definable risk factors for drug-induced immunopathology. The induction of a drug-specific immune response can be influenced by the age of the patient; underlying genetic or metabolic factors, which may restrict ability to initiate a drug-specific immune response; the chemical properties of the drug, largely its protein reactivity; and the dose and duration of treatment as well as the route of drug administration. The elicitation of drug-induced immunopathology is a function of the persistence of a drug-specific immune response; the frequency of drug treatment and its dose and duration; and probable constitutional factors that may determine in an important way the efficiency with which a drug-specific immune response can be translated into a systemic allergic reaction.