Necrotizing cellulitis caused by Apophysomyces elegans at a patch test site.

Plant material occasionally is used in patch testing to diagnose contact dermatitis. Serious adverse reactions to this practice are extremely uncommon. The authors report on a 68-year-old non-insulin-dependent diabetic gentleman with hand dermatitis in whom severe necrotizing cellulitis developed caused by Apophysomyces elegans, a subtype of mucormycosis, at the site of a patch test to a snapdragon plant from his garden.