Which term describes an open sore on the skin or mucous membrane?

• A. Lesion
• B. Abrasion
• C. Erosion
• D. Ulcer

Answer: (D)

An open sore on the skin or mucous membrane is an ulcer. An ulcer represents a break in surface tissues with loss of tissue integrity that can extend into deeper layers and often heals slowly. This distinguishes it from other terms: a lesion is any abnormal tissue change; an abrasion is a superficial scrape removing only the outermost skin; an erosion is a shallow loss of surface epithelium without deeper tissue destruction. So the best term for an open sore is ulcer.