Rash

A rash is a change in the skin which affects its appearance or texture. A rash may be localised to one part of the body, or affect all the skin. Rashes may cause the skin to change colour, 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.

Common causes of rashes include:

allergies, for example to foods, dyes, medicines, insect stings; such rashes are often called hives

skin contact with an irritant

infection or reaction to a vaccine

skin diseases such as eczema or acne

autoimmune disorders such as psoriasis

cancer or other disease

pregnancy

exposure to sun or heat