Disulfite-induced acute intermittent urticaria with vasculitis.

Recognition of sulfite sensitivity by the practicing dermatologist has become increasingly important. A wide spectrum of anaphylactoid reactions can occur after ingestion of sulfite additives in foods and medications. We report the case of a 47-year-old man with severe acute intermittent urticaria. A placebo-controlled oral challenge test with 50 mg sodium disulfite resulted in an acute urticaria attack. A biopsy taken 5 h after the appearance of the urticaria demonstrated a leukocytoclastic vasculitis with eosinophilia. Avoiding foods and drugs containing sulfites is often difficult due to its widespread use. Therefore, the patient should be equipped with a medical emergency kit.