In smallpox, which feature best describes the rash development?

• A. Rash lesions progress asynchronously.
• B. Rash begins on the extremities and moves inward.
• C. Rash lesions are in the same stage of development and scab over in about two weeks.
• D. Rash resolves within a few days.

Answer: (C)

Smallpox rash progresses in a synchronized way across the body. All lesions go through the same sequence—macule to papule to vesicle to pustule to crust—at roughly the same time, so you see a uniform stage of evolution in widespread areas. They typically crust over about two weeks after the rash begins. This pattern helps distinguish smallpox from diseases like varicella (chickenpox), where lesions are at different stages in different areas.