A rash is a change in the skin due to skin irritation. Most rashes go away on their own or require only minor treatment. Some rashes may need medical attention. Some rash symptoms are redness, itching, bumps, redness, and swelling. Some causes of rashes are allergic reactions; plants such as poison ivy; or irritation due to jewelry, chemicals, or makeup. Rashes are also sometimes symptoms of another condition, as with impetigo or scabies. Treatments vary based on the cause, but many can be treated with medications.