This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blistering disorders, Subject name: Dental
[{'content': '"Row of tombstones" appearance is seen in: \nSelect and explain. \nA. Irritant dermatitis, B. Pemphigus, C. Pemphigoid, D. Herpes zoster', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Histopathology of pemphigus vulgaris Earliest changes -intercellular edema + disappearance of intercellular bridges in the lower most epidermis. Loss of coherence between epidermal cells (acantholysis) --> formation of clefts -->bullae in the suprabasal zone. Basal cells remain attached to the dermis, producing a "tombstone" appearance. Acantholytic cells are present in the bulla cavity. Scanty perivascular inflammatory infiltrate composed of lymphocytes, histiocytes and occasional eosinophils, neutrophils, and plasma cells is present', 'role': 'assistant'}]