Allergies to sulfonamide antibiotics and sulfur-containing drugs.

OBJECTIVE: To provide a literature review and clinical summary of the evaluation and management of sulfonamide drug reactions. DATA SOURCES: Published English-language medical literature. STUDY SELECTION: Selected trials of drug desensitization protocols.
RESULTS: Obtaining a detailed history is invaluable in assessing a history of reactions to sulfonamide medications, because allergy to these drugs remains a clinical diagnosis at present. Numerous efficacious drug desensitization protocols for management have been published and are reviewed in detail.
CONCLUSIONS: The term sulfa allergy is imprecise and misleading and therefore should be discouraged. There are important distinctions between sulfonylarylamines (antimicrobial sulfonamides), nonarylamine (nonantimicrobial) sulfonamides, and sulfones, with regard to allergic and other adverse drug reactions. Most reactions to sulfonylarylamines probably result from multifactorial immunologic and toxic metabolic mechanisms, whereas less is known about the precise mechanisms of reactions to other sulfur-containing drugs.