Drug allergy - An overview

Drug allergy is an immunologically mediated adverse drug reaction. It is classified based on the type of hypersensitivity reaction and timing of onset of reaction. Immediate reactions are IgE mediated and delayed reactions are non IgE mediated. A detailed history, review of records and clinical examination are necessary but not sufficient to confirm drug allergy. Skin testing is helpful in diagnosing type I drug hypersensitivity reactions but it is standardized only for few drugs. Treatment of drug allergy includes withdrawal of the offending drug and timely management of anaphylaxis and other life threatening conditions. Options for continuing treatment include use of alternative drug or desensitization.