Current Concepts of Dermatitis Herpetiformis

Abstract

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, glutendependent 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.

Autoantibodies Against the Immunodominant Bullous Pemphigoid Epitopes Are Rare in Patients With Dermatitis Herpetiformis and Coeliac Disease

“…The aim of our current work was to investigate whether intermolecular epitope spreading may explain why individuals with gluten-induced autoimmunity carry an elevated risk for BP. This idea was inspired by a current hypothesis that DH develops as an intermolecular epitope spreading phenomenon against TG3 following a sub-clinical or neglected occurrence of CD (2,31). However, the presence of BP180-NC16A IgG autoantibodies was specific for patients with BP: only a minority of CD (4.7%) and DH (6.5%) samples were positive in BP180-NC16A IgG tests, and the ELISA values in these samples were clearly lower than those of the BP samples.…”

“…Bullous pemphigoid (BP) and dermatitis herpetiformis (DH) are both autoimmune subepidermal blistering skin diseases. Intense pruritus is present in both diseases, but tense bullae are typical for BP, whereas symmetrically distributed small blisters, papules and excoriations in elbows, knees and buttocks are common in DH (1,2). BP typically affects people aged 75-80 years (1), while DH patients are generally younger, its incidence being highest in individuals aged 50-69 years (2).…”

“…Intense pruritus is present in both diseases, but tense bullae are typical for BP, whereas symmetrically distributed small blisters, papules and excoriations in elbows, knees and buttocks are common in DH (1,2). BP typically affects people aged 75-80 years (1), while DH patients are generally younger, its incidence being highest in individuals aged 50-69 years (2). The incidence of BP has recently increased in several countries (3) and that of DH decreased (4).…”

“…Autoantibodies against cutaneous proteins play a central role in the pathogenesis of DH and BP, but the factors that lead to the breakage of immunotolerance and disease onset are still largely unknown (1). DH is a cutaneous manifestation of coeliac disease (CD) and both CD and DH are characterized by the targeting of enzymes of the transglutaminase family by IgA autoantibodies (2). Proteolytic gliadin peptides from ingested gluten induce production of IgA class autoantibodies against both native and gliadin-associated tissue transglutaminase 2 (TG2) (2).…”

“…DH is a cutaneous manifestation of coeliac disease (CD) and both CD and DH are characterized by the targeting of enzymes of the transglutaminase family by IgA autoantibodies (2). Proteolytic gliadin peptides from ingested gluten induce production of IgA class autoantibodies against both native and gliadin-associated tissue transglutaminase 2 (TG2) (2). These antibodies are detectable in the serum and small bowel mucosa of CD patients, but in only about 75% of DH patients (6,7).…”