Erythema elevatum diutinum arising in the setting of dermatitis herpetiformis.

Dermatitis herpetiformis is an autoimmune blistering disease characterized by granular deposits of immunoglobulin A (IgA) in dermal papillae. Erythema elevatum diutinum is a chronic form of vasculitis associated with IgA paraproteinemia. We report a patient with dermatitis herpetiformis who developed characteristic erythema elevatum diutinum lesions on the elbows and knees despite sulfone therapy. We speculate that the different patterns of IgA deposition in the skin account for the clinical manifestation of these 2 uncommon disorders.