Teea Salmi, Kaisa Hervonen
DOI: 10.2340/00015555-3401

Dermatitis herpetiformis (DH) is an autoimmune skin disease that causes itchy, blistering rash, typically on the elbows, knees and buttocks. DH and coeliac disease share the same genetic background, gluten-dependent enteropathy and antibody response against tissue transglutaminase. DH is currently considered a cutaneous manifestation of coeliac disease, and the prevailing hypothesis is that DH develops as a late manifestation of subclinical coeliac disease. The incidence of DH is decreasing contemporarily with the increasing incidence of coeliac disease. The IgA immune response in DH skin is directed against epidermal transglutaminase, while the autoantigen in the gut is tissue transglutaminase. Granular IgA deposition in the papillary dermis is pathognomonic for DH, and is a finding used to confirm the diagnosis. The treatment of choice for DH is a life-long gluten-free diet, which resolves the rash and enteropathy, increases quality of life, and offers a good long-term prognosis.

Dermatitis herpetiformis is an itchy, blistering rash, which occurs on the elbows, knees and buttocks. Dermatitis herpetiformis is considered a cutaneous manifestation of coeliac disease. Even though obvious gastrointestinal symptoms are rare in dermatitis herpetiformis, intestinal coeliac-type villous atrophy or inflammation is present at diagnosis. The diagnosis is confirmed by skin biopsy revealing typical IgA deposits, and the majority of patients also have coeliac autoantibodies in the serum. The treatment of choice for dermatitis herpetiformis is a life-long gluten-free diet, which resolves the rash and enteropathy, increases quality of life, and offers a good long-term prognosis.