Hypersensitivity vasculitis is an extreme reaction to a drug, infection, or foreign substance. It leads to inflammation and damage to blood vessels, mainly in the skin. The term is not used much currently because more specific names are considered more precise.

Cutaneous small vessel vasculitis; Allergic vasculitis; Leukocytoclastic vasculitis

Hypersensitivity vasculitis, or cutaneous small vessel vasculitis, is caused by:

• An allergic reaction to a drug or other foreign substance
• A reaction to an infection

It usually affects people older than age 16.

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

Hypersensitivity vasculitis may look like systemic, necrotizing vasculitis, which can affect blood vessels throughout the body and not just in the skin. In children, it can look like Henoch-Schonlein purpura.

Symptoms may include:

• New rash with tender, purple or brownish-red spots over large areas
• 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 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 systemic 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 that have caused an allergic reaction in the past.

Published Date: May 02, 2021
Published By: Diane M. Horowitz, MD, Rheumatology and Internal Medicine, Northwell Health, Great Neck, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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