This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
[{'content': 'Intraepidermal blister formation is seen in \nSelect and explain. \nA. Pemphigus Vulgaris, B. Pemphigoid, C. Dermatitis herpetiformis, D. None of the above', 'role': 'user'}, {'content': "Answer: A \nExplanation: Pemphigus vulgaris a. Blisters in pemphigus vulgaris are wiraepidermal while those in bullous pemphigoid are subepidermal. b. Typical acantholytic (Tzanck) cells are seen in pemphigus vulgaris but not in bullous pemphigoid. c. Nikolsky 's sign is positive in pemphigus vulgaris but not in bullous pemphigoid.", 'role': 'assistant'}]