Definition

Henoch-Schonlein purpura (HSP) is inflammation of the blood vessels in the skin and other organs. It results in a specific rash when the skin is involved. The rash looks like bruising or small dots, referred to as purpura.

Causes

HSP is caused by an abnormal reaction of the immune system. It attacks healthy blood vessels. It is not clear why this happens.

The change in the immune system may be triggered by:

• Bacterial or viral infections—some can be related to an insect bite
• Certain medicines
• Recent exposure to certain vaccines

Risk Factors

HSP is most common in children who are 2 to 11 years of age. The risk of HSP is higher in people who have had:

• An upper respiratory infection
• Exposure to vaccines, chemicals, cold weather, or insect bites

Symptoms

Symptoms may last for 4 to 6 weeks and may include:

• Reddish-purple raised spots on the buttocks, legs, or elbows
• Bruising that often happens below the waist
• Pain in the joints—usually the knees and ankles
• Belly pain
• Blood in the urine
• Swelling of the ankles
• Swelling of the scrotum in males
• Fever
• Blood in the stool
• Vomiting

Diagnosis

You will be asked about your symptoms and health history. A physical exam may be done.

Other tests may be:

• Blood tests
• Urine tests
• Stool sample
• Skin biopsy from an area of the rash

Skin Biopsy Copyright © Nucleus Medical Media, Inc.

Treatment

HSP usually gets better on its own. Medicines may be used to:

• Ease joint swelling and pain
• Treat bacterial infections
• Change how the immune system works

Prevention

There are no known guidelines to prevent HSP.