Any change in the skin which affects its appearance or texture. A rash may be localized to one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, dry, cracked or blistered, swell and may be painful.

a widespread rash usually occurring in children but can occur in adults. An exanthem can be caused by toxins, drugs, or microorganisms, or can result from autoimmune disease. It can be contrasted with an enanthem.