A young boy presented with peri-oral blisters. Some of which are weeping and others are crusted. What is the single most appropriate diagnosis?

The key is A. Impetigo. [Distribution of varicella zoster is centripetal (more in central area (trunk) and less in limbs and face. On the other hand if blisters are present mainly on face or limbs and/or described as golden, yellow or honey coloured crusts, are impetigo].