This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Skin
[{'content': 'A 45 yr old female developed recurrent oral erosions followed by multiple flaccid bullae on trunk and extremities. A tzanck smear showed acantholytic cells and direct immunofluoroscence showed intercellular IgG deposits in the epidermis. The most probable diagnosis is: \nSelect and explain. \nA. Bullous Pemphigoid, B. Stevens Johnson syndrome, C. Herpes simplex 1 infection, D. Pemphigus vulgaris', 'role': 'user'}, {'content': "Answer: D \nExplanation: Recurrent, painful oral lesions and cutaneous lesions in the form of flaccid bullae are characteristic of phemphigus vulgaris Positive Tzanck smear, IgG deposits on direct immunofluoroscence positive nikolsky's sign are features of phemphigus vulgaris. Ref: Textbook of Dermatology, Venereology and Leprology By Devinder Mohan Thappa, 2nd Edition, Chapter 12, Pages 152-53; Dermatology (A coloured Hand Textbook) By R. J. G. Rycroft, S. J. Robeson, Sarah H. Wakeli, 2nd Edition, Pa 1, Pages 54, 55", 'role': 'assistant'}]