A rash is a change of the skin which affects its color, appearance or texture. A rash may be localized in 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. The causes, and therefore treatments for rashes, vary widely.
Diagnosis must take into account such things as the appearance of the rash, other symptoms, what the patient may have been exposed to, occupation, and occurrence in family members. The diagnosis may confirm any number of conditions.