Erythema elevatum diutinum in association with dermatitis herpetiformis
A 50-year-old male presented with firm skin-colored and erythematous nodules over the knuckles, elbows, buttocks, knees, and lower legs which gradually increased in size in since 3 years duration []. Complete blood picture, liver function tests, urine routine, blood sugar were within normal limits. Biopsy of the nodules of the knuckles showed focal parakeratosis and mild spongiosis in the epidermis, perivascular neutrophilic infiltrate in the dermis, neutrophils in the vessel wall and leukocytoclasia []. Immunofluorescence showed linear IgA deposits in the basement membrane zone and weak granular perivascular C3 and fibrinogen deposits []. Four years ago itchy vesicles over the back and arms were detected in the patient. Biopsy of the vesicular lesions were consistent with dermatitis herpetiformis []. He was administered dapsone which leads to disappearance of lesions with recurrence after stopping treatment. With the clinical presentation, biopsy and immunofluorescence results, a diagnosis of erythema elevatum diutinum on a background of dermatitis herpetiformis was made.