Diaper rash: An irritation of the skin caused by dampness, the interaction of urine (and ammonia from the urine), and feces. A rash is any skin swelling (bumps) or blotches on a baby (can be red, skin-colored, or slightly lighter or darker than skin color).

Alternative Names

Baby rash; Diaper rash; Miliaria/Milia; Prickly heat; Candidal (yeast) diaper rash