[Dermatitis herpetiformis. An update of the pathogenesis]

[Dermatitis herpetiformis]

Dermatitis herpetiformis (DH) is a genetically determined, gluten sensitive autoimmune bullous dermatosis related to celiac disease in which granular, insoluble aggregates in the papillary dermis of epidermal transglutaminase (TG3), immunoglobulin A (IgA), and fibrinogen are present. Detection of the dermal IgA-TG3 immune complex is the gold standard of diagnosis. DH develops in a subpopulation of patients with gluten sensitive enteropathy, characterized by itching, erythematous, excoriated papules showing characteristic distribution over the knees, elbows and buttocks; vesicles are rarely seen. The primary therapy of DH is a strict, lifelong gluten-free diet, and it may be necessary to temporarily give dapsone in case of severe symptoms.

Dermatitis herpetiformis: from the genetics to the development of skin lesions

Dermatitis herpetiformis (DH) is a rare autoimmune disease linked to gluten sensitivity with a chronic-relapsing course. It is currently considered to be the specific cutaneous manifestation of celiac disease (CD). Both conditions are mediated by the IgA class of autoantibodies, and the diagnosis of DH is dependent on the detection of granular deposits of IgA in the skin. There is an underlying genetic predisposition to the development of DH, but environmental factors are also important. This paper describes these different factors and discusses the known mechanism that lead to the development of skin lesions.

Dermatitis herpetiformis presenting as digital petechiae

We present a 15-year-old female patient with a 6-month history of recurrent painful petechiae on the fingers and feet. Trauma or pressure were denied, but she reported recurrent tonsillitis and urinary tract infections and a single event of bilateral scotoma. Extensive investigations (e.g., echocardiography) for a suspected diagnosis of septic emboli were unremarkable. Routine histopathology, direct and indirect immunofluorescence, and esophagogastroduodenoscopy led to the diagnosis of dermatitis herpetiformis. The therapeutic strategy comprised gluten-free diet and dapsone to alleviate the symptoms. Dermatitis herpetiformis should be included in the differential diagnosis of palmar or plantar petechiae, especially when occurring in children or young adults.