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
"Row of tombstones" appearance is seen in: 
Select and explain. 
A. Irritant dermatitis, B. Pemphigus, C. Pemphigoid, D. Herpes zoster
B: Pemphigus
Answer: B: Pemphigus 
Explanation: 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