Dermatitis herpetiformis is an autoimmune blistering disease that appears as a 
cutaneous manifestation of gluten intolerance. It is one of a group of disorders 
that have gluten sensitivity in common, including celiac disease and gluten 
ataxia. Patients with dermatitis herpetiformis present with a pruritic 
papulovesicular rash on extensor surfaces and on the buttocks. Immunological 
studies demonstrate the presence of specific immunoglobulin (Ig) A 
anti-endomysial and anti-transglutaminase antibodies. The finding of granular 
deposits of IgA along the dermal-epidermal junction is pathognomonic of 
dermatitis herpetiformis. Treatment of dermatitis herpetiformis is based on a 
life-long, strict gluten-free diet, which improves all clinical aspects of 
gluten sensitivity, and dapsone, a drug that is only effective for the skin 
manifestations.