This fourth volume in an exciting and detailed series on contact allergens and drug allergy provides monographs of all 507 systemic drugs which have caused delayed-type cutaneous drug hypersensitivity reactions and/or occupational allergic contact dermatitis. The monographs present: Identification section; Occupational allergic contact dermatitis; and Cutaneous adverse drug reactions from systemic drugs caused by type IV (delayed-type) hypersensitivity, as shown by positive patch tests (e.g. maculopapular eruption, acute generalized exanthematous pustulosis [AGEP], symmetrical drug-related intertriginous and flexural exanthema [SDRIFE], fixed drug eruption, drug reaction with eosinophilia and systemic symptoms [DRESS], and photosensitivity). Separate chapters present an overview of the spectrum of allergic cutaneous drug reactions, diagnostic tests, immediate contact reactions (contact urticaria), and systemic drugs that have acquired delayed-type hypersensitivity only by cross-reactivity.