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: Unknown
A 45-year-old male has multiple grouped vesicular lesions present on the T10 segment dermatome associated with pain The most likely diagnosis is - 
Select and explain. 
A. Herpes zoster, B. Dermatitis herpetiformis, C. Herpes simplex, D. Scabies
A: Herpes zoster
Answer: A: Herpes zoster 
Explanation: Ans. is 'a' i.e., herpes zoster * Here is a D/d of commonly asked vesico bullous disorders* So the crux is -Painful lesions are seen in Herpes infection.Painless lesions are seen in-Dermatitis herpetiformis Pemphigoid Pemphigus Erythema multiformeDermatomal involvement-Herpes zosterItchy lesions-Dermatitis herpetiformisIntraepidermal-Herpes and pemphigusSubepidermal-Dermatitis herpetiformis Pemphigoid Erythema multiforme