What is Henoch-Schönlein purpura?

Henoch-Schönlein purpura (HEN-awk SHERN-line PURR-purr-ah), or HSP, is a condition in which the blood vessels swell up. It causes a bumpy, non-itchy, reddish-purple rash on the skin. It can cause joints to swell and turn red, and it may cause stomach pain and bleeding. It can also cause kidney problems.

Anyone can get HSP, but it is more common in children younger than 10 years. It usually occurs in the late fall through early spring. It is linked to many viral and bacterial illnesses. Most people get better within four to six weeks with no long-term problems.

How do I know if my child has it?

Rashes, joint pain, and stomach pain are the most common symptoms of HSP. Everyone who has HSP will get a rash. The rash may start as small red marks that don't fade when you push on them. After several days, the rash may turn into raised, purple bruises that don't itch. The bruises may run together to make larger ones. The rash can be anywhere on the body, but is usually on the buttocks, around the belt line, on the elbows, or on the back of the legs and feet.

Joint pain from HSP is usually in the knees and ankles. About 75 percent of people with HSP will have this pain. It can come before, during, or after the rash.

Stomach pain happens in about one half of people with HSP. The pain may cause your child to throw up or bleed inside his or her stomach.

The pain usually starts about one week after the rash, but it may happen before the rash. The most serious symptom is kidney problems. One half of people with HSP will develop kidney problems. This happens later in the illness. HSP may cause the kidneys to not work as well as they should. There may be blood or protein in the urine. Most of the time, the kidney problems go away without lasting harm.

What tests will the doctor do?

There is no test to confirm HSP. But, there are tests to check for complications or to see if your child has another condition. Your doctor will ask questions about the rash and do a physical exam. He or she may do a blood test to see if your child has an infection, or to see if your child's kidneys are working right. If your child has stomach pain, the doctor may do an imaging test to see what is causing the pain.

Can it cause serious problems?

There is a small risk of serious problems. Sometimes the stomach pain from HSP is caused by a problem in the bowel. Your doctor will tell you if your child needs surgery to fix it. HSP can cause serious kidney disease. It can also cause swelling in the scrotum, which blocks blood flow. This can be very painful and needs to be fixed with surgery. Other rare problems may include pneumonia, heart attack, and seizures.

How is it treated?

HSP tends to get better after four to six weeks of rest. Medicines such as acetaminophen (one brand: Tylenol) or ibuprofen (one brand: Motrin) may help with mild joint or stomach pain. Your doctor may prescribe a steroid medicine if your child is in a lot of pain or if the kidneys are involved. Your doctor may have you take your child to a kidney specialist if the problems are serious.

About one third of patients with HSP will get it again. This is more common in those who have kidney problems. It is important to follow up with your doctor regularly, especially within the first six months of your child's diagnosis.

Where can I get more information?

Your doctor

American Academy of Family Physicians

• Web site: https://familydoctor.org

National Kidney and Urologic Diseases Information Clearinghouse

• Telephone: 1-800-891-5390

• Web site: http://www.kidney.niddk.nih.gov/kudiseases/pubs/HSP/index.htm

Vasculitis Foundation

• Telephone: 1-800-277-9474

• Web site: http://www.vasculitisfoundation.org/HenochSchonleinpurpura