Hypersensitivity vasculitis

Allergic vasculitis; Leukocytoclastic vasculitis; Cutaneous vasculitis

Hypersensitivity vasculitis is caused by an allergic reaction to a drug or other foreign substance. It can also be a reaction to an infection. Most often it affects people older than age 15.

Often, the cause of the problem cannot be found even with a careful study of medical history.

Hypersensitivity vasculitis may look like necrotizing vasculitis, which can affect blood vessels throughout the body.

Symptoms may include:

• New rash over large areas
• Purple-colored spots and patches on the skin
• Skin sores mostly located on the legs, buttocks, or trunk
• Blisters on the skin
• Hives (urticaria), may last longer than 24 hours
• Open sores with dead tissue (necrotic ulcers)

The health care provider will base the diagnosis on symptoms. The provider will evaluate how your skin looks after you have taken certain medicines or are exposed to a foreign substance (antigen).

Results from an ESR test (erythrocyte sedimentation rate test) may be high.

Skin biopsy shows inflammation of the small blood vessels. You may also have other tests to detect this condition.

The goal of treatment is to reduce inflammation.

Your provider may prescribe aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), or corticosteroids to reduce inflammation of the blood vessels. (DO NOT give aspirin to children except as advised by your provider).

Your provider will tell you to stop taking medicines that could be causing this condition.

Hypersensitivity vasculitis most often goes away over time. The condition may come back in some people.

People with ongoing vasculitis should be checked for necrotizing vasculitis.

Complications may include:

• Lasting damage to the blood vessels or skin with scarring
• Inflamed blood vessels affecting the internal organs

Call your provider if you have symptoms of hypersensitivity vasculitis.

DO NOT take medicines which have caused an allergic reaction in the past.