Vasculitis is inflammation of the blood vessels. This inflammation can damage and narrow the blood vessels, causing a rash, a change in sensation, fatigue, or other symptoms.

Vasculitis has many possible causes, including allergic reactions and certain diseases, such as lupus.

Bleeding from the blood vessel may cause bruises or blood spots under the skin. Vasculitis can decrease blood supply to tissues or organs, causing blood clots, pain, tissue damage, and organ malfunction.

Treatment depends on the cause of the vasculitis. Some cases may be self-correcting. Treatment often includes anti-inflammatory medicine, such as corticosteroids.