<prompt> Extermely pruritic excoriation papules on buttocks with autoantibodies against epidermal transglutaminase and IgA deposition in dermis on immuno-histological examination of normal perilesional skin. Diagnosis is:Pemphigus vulgarisPemphigoidLinear IgA diseaseDermatitis herpetiformis  <response>: D i.e. Dermatitis herpetiformis 