Alternate Names: Vasculitis; Vasculitis - allergic; Vasculitis - hypersensitivity

Causes and Risks: Vasculitis occurs because of inflammation and damage to blood vessels. The inflammation of allergic vasculitis is the result of an allergic reaction to a drug or other foreign agent.

Prevention: Avoid exposure to medications to which there are known allergies.

Symptoms:

• skin lesions usually located on legs, buttocks, or trunk
• palpable (able to be felt with the fingers) purpura
  • multiple papules (small, solid, raised skin areas)
  • purpura (bleeding into the skin)
• blisters on the skin
• urticaria (hives), may last longer than 24 hours
• necrotic ulcers (open sores with dead tissue)

Signs and Tests: The diagnosis is primarily based on a history of skin lesions that develop after exposure to medications or a foreign substance (antigen) and the clinical presentation (pattern of symptoms).

• The ESR (sed rate) may be elevated.
• Skin biopsy shows vasculitis (inflammation of the blood vessels).

Treatment: Treatment is aimed at reducing the inflammation, allowing the natural healing process to occur. If possible, stop exposure to the causative medication (or other antigen). Aspirin or corticosteroids may be prescribed to reduce inflammation of the blood vessels. (DO NOT give aspirin to children except as advised by the health care provider.)

Prognosis: Allergic vasculitis usually resolves in time.

Complications:

• permanent damage to the blood vessels or skin with scarring
• vasculitis affecting the internal organs (kidney, bone, and so on)

Call for an appointment with your health care provider if symptoms indicate allergic vasculitis may be present.