This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vesiculobullous (Blistering) Disorders, Subject name: Skin
[{'content': '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: \nSelect and explain. \nA. Dermatitis herpetiform, B. Pemphigus vulgaris, C. Nummular eczema, D. Bullous pemphigoid', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. a. Dermatitis herpetiformDermatitis herpetiformis is also known as duhring -Brocq disease', 'role': 'assistant'}]