Dermatitis herpetiformis.

Dermatitis herpetiformis (DH) is a chronic, polymorphic, pruritic skin disease that develops mostly in patients with latent gluten-sensitive enteropathy. DH patients usually present with skin manifestations only and are not aware of the underlying small-bowel problems. Owing to the granular immunoglobulin (Ig) A deposition at the tips of the papillary dermis and to the subepidermal blister formation associated with neutrophilic accumulations underlying the basement membrane, DH is considered to be an autoimmune blistering disease. Contrary to the other bullous disorders, DH patients have no circulating autoantibodies binding to the cutaneous basement membrane components or to other adherent structures of the skin, but they have gluten-induced IgA autoantibodies against transglutaminase (TG) 2 and TG3. The serum IgA against tissue TG2 is a most specific and sensitive serologic marker of gluten-sensitive enteropathy and is equivalent to the perviously described IgA endomysium antibodies. DH could be a cutaneous IgA-epidermal TG3 immunocomplex disease, developing only in a few patients with gluten-sensitive enteropathy as a second gluten-dependent disease. The main treatment of DH today is a strict, life-long gluten-free diet. Untreated DH patients should be regularly monitored for malabsorption and lymphomas. Associated autoimmune diseases are more common among DH patients. Family screening for gluten sensitivity is also strongly suggested.