subject: Dermatitis herpetiformis clinical features and treatment [print this page] Dermatitis herpetiformis clinical features and treatment
Dermatitis herpetiformis is an uncommon, chronic,intensely itchy disorder in which subepidermal blisteringusually occurs.
Aetiology and pathogenesis There is a close association with HLA-B8 and DRW3,gluten-sensitive enteropathy, and deposition of IgA in thedermal papillae throughout the skin. The enteropathy maynot be symptomatic, but it is likely that absorbed products derived from gluten are important in the pathogenesisof the skin lesions. Abnormal immunity in patients with dermatitis herpetiformis is suggested by an increasedincidence of organ-specific autoimmune disease, and afew patients (as with coeliac disease) develop small bowel lymphoma. The skin lesions are a result of activation ofdense clusters of neutrophils in the dermal papillae, producingdamage and then fluid accumulation.
Clinical features Dermatitis herpetiformis usually begins in young adults,but can begin at any age and can persist indefinitely. The initial lesions are very itchy grouped weals or papules, onwhich arise small blisters. Extensor surfaces are the characteristic sites, especially the elbows, knees,shoulders, buttocks and scalp. Oral lesions are sometimes seen.
Diagnosis The diagnosis is best made from finding typical histologyin an early lesion and IgA deposition in unaffected skin.(In the lesions the IgA can disappear as a result of the inflammatory infiltrate.) A jejunal biopsy usually showssubtotal villous atrophy. Potassium iodide, both systemicallyand topically, provokes dermatitis herpetiformis and has occasionally been used as a diagnostic test.
Treatment Dapsone has a dramatic beneficial effect in this condition,probably by modulating the neutrophil myeloperoxidase enzyme system, and/or the alternative pathway of complement activation. Haemolytic anaemia can occur, in whichcase sulphamethoxypyridazine is an alternative. A gluten freediet is helpful in most patients and may reduce the likelihood of intestinal lymphoma.
welcome to Insurances.net (https://www.insurances.net)
