A rash is when skin gets irritated. A rash can be red, bumpy, scaly, blisters, or itchy — or all of those things at once! Another name for a rash is dermatitis.
Lots of things can cause rashes. A chemical, like a soap, might irritate your skin. Or a rash can happen when you touch something you're allergic to, like poison ivy. Skin conditions like eczema and dandruff also cause rashes.