Clinical assessment of drug-induced disease.

Physicians are often confronted with patients who state that they are "allergic" to a drug or drugs. Knowing which medications can be prescribed safely is therefore difficult, and care of such patients frustrating. The goal of this review is to help physicians develop management plans for patients who present with drug-induced diseases. It provides information that allows physicians to differentiate between reactions that are truly allergic in nature and those that are not immunologically mediated. Relevant information on medical history, physical findings, and laboratory tests that may be helpful in the assessment are discussed, and guidance is provided on when and if a drug may be safely readministered. Unfortunately, however, until we are able to better understand the mechanisms responsible for drug-induced reactions, our management tools will remain limited.