<prompt> A30-year-old male had severely itchy popular vesicular lesions on extremities knee, elbows and buttocks for one year. Direct immunofluorescence staining of the lesions showed IgA deposition at dermo epidermal junction. The most probable diagnosis is:Dermatitis herpetiformPemphigus vulgarisNummular eczemaBullous pemphigoid  <response>: Ans. a. Dermatitis herpetiformDermatitis herpetiformis is also known as duhring -Brocq disease 