What Is Henoch-Schönlein Purpura?

Henoch-Schönlein purpura (HEH-nok SHOON-line PURR-pyuh-ruh) is a condition that makes small blood vessels get swollen and irritated. This inflammation is called vasculitis. It usually happens in the skin, intestines, and kidneys.

Inflamed blood vessels in the skin can leak blood cells, causing a rash called purpura. Vessels in the intestines and kidneys also can swell and leak.

Henoch-Schönlein purpura (HSP) is also called allergic purpura, anaphylactoid purpura, or IgA vasculitis.

Who Gets Henoch-Schönlein Purpura?

Henoch-Schönlein purpura happens much more often in kids than in adults, usually between ages 3 and 10. It's one of the most common forms of vasculitis in children, and boys get it about twice as often as girls.

Most children with HSP fully recover within a month and have no long-term problems. Kids whose kidneys are affected will need to see a doctor for regular checkups to monitor kidney function.

What Causes Henoch-Schönlein Purpura?

No one really knows what causes Henoch-Schönlein purpura. But doctors do know that it happens when the body's immune system doesn't work as it should. A protein called immunoglobulin A (IgA) is a type of antibody that works to fight infections. In HSP, IgA also gets placed in the blood vessels and causes swelling and bleeding.

This immune reaction often happens after a bacterial or viral infection of the upper respiratory tract (sinuses, throat, or lungs). It is seen more often in fall, winter, and spring. Other less common triggers include some medicines, reactions to food, insect bites, and vaccinations.

HSP cannot be passed from one person to another.

What Are the Signs & Symptoms of Henoch-Schönlein Purpura?

Common signs and symptoms of Henoch-Schönlein purpura include:

The rash happens in all cases and is what helps doctors diagnose HSP. It can look like pinpoint red dots (called petechiae [puh-TEEK-ee-ee]), bruises, or sometimes blisters. The rash usually is on the legs and buttocks, but can be on other parts of the body, such as the elbows, arms, face, and trunk.

Most kids with HSP also have joint pain and swelling. These symptoms can happen before the rash appears. This often affects the ankles and knees, but can happen in other joints like the hands, elbows, and feet.

Stomach pain usually starts a week after the rash. Pain may come and go and can be accompanied by nausea, vomiting, or diarrhea. Some kids will have blood in the stool (caused by leaky blood vessels), but it may not be visible.

HSP can affect the kidneys in some cases. Small amounts of blood or protein might be found in the urine, and the urine may look bloody.

Symptoms of Henoch-Schönlein purpura usually last for about a month.

How Is Henoch-Schönlein Purpura Diagnosed?

Doctors can easily diagnose Henoch-Schönlein purpura if the rash is on the legs and buttocks, especially if a child also has belly or joint pain. Diagnosis might be harder if joint pain or belly problems start before the rash appears, or if symptoms take several weeks to show up.

The doctor also may order blood tests to look for signs of infection, anemia, or kidney disease. If belly pain is severe, imaging tests (like X-rays or an ultrasound) may be needed. A stool test can check for blood in the stool (poop). A urine sample can reveal blood or protein in the urine.

Up to half of kids who develop HSP will have problems with their kidneys. So the doctor will probably check kidney function over several months. If the HSP might have caused kidney damage, a child may need to see a kidney doctor (nephrologist).

How Is Henoch-Schönlein Purpura Treated?

Most of the time, Henoch-Schönlein purpura goes away on its own without treatment. To help your child feel better, the doctor may recommend medicines such as:

  • antibiotics, if an infection is causing the HSP
  • pain relievers (such as acetaminophen)
  • anti-inflammatory medicines (such as ibuprofen) to relieve joint pain and inflammation
  • corticosteroids (such as prednisone) for severe belly pain or kidney disease

Also, a child might have to stop taking a medicine if there's a chance it caused the HSP.

While at home, try to keep your child as comfortable as possible. Be sure your child gets plenty of rest and drinks fluids.

A child with HSP who stops eating or drinking or gets severe belly pain or kidney problems might need treatment in a hospital.

What Else Should I Know?

Most children with HSP fully recover within a month and have no long-term problems. Kids whose kidneys are affected will need to see a doctor for regular checkups to monitor kidney function.

Some kids who have HSP get it again, usually a few months after the first episode. If it does come back, it's usually less severe than the first episode.

Back to Articles

Related Articles

A to Z: Idiopathic Thrombocytopenic Purpura

Learn about immune system responses and conditions that can affect the blood.

Read More

Stool Tests

Your child's doctor may order a stool collection test to check for blood, bacteria, ova, or parasites. Find out how this test is performed and when you can expect the results.

Read More

Kawasaki Disease

Kawasaki disease is an illness that causes inflammation in blood vessels throughout the body. When symptoms are noticed early and treated, kids begin to feel better within a few days.

Read More

Kidney Disease

Sometimes, the kidneys can't do their job properly. In teens, kidney disease is usually due to infections, structural issues, glomerulonephritis, or nephrotic syndrome.

Read More

Kidney Diseases in Childhood

The kidneys play a critical role in health. When something goes wrong, it could indicate a kidney disease. What are kidney diseases, and how can they be treated?

Read More

Anemia

Anemia is common in teens because they undergo rapid growth spurts, when the body needs more nutrients like iron. Learn about anemia and how it's treated.

Read More

Immune System

The immune system, composed of special cells, proteins, tissues, and organs that protect against germs and microorganisms, is the body's defense against disease.

Read More

Anemia

Anemia happens when there aren't enough healthy red blood cells in the body. It can be caused by many things, including dietary problems, medical treatments, and inherited conditions.

Read More

What's Anemia?

What does it mean when a kid has anemia? Learn about anemia, why kids get it, and how it's treated in our article for kids.

Read More

Your Immune System

The immune system keeps you healthy. How does it work? Find out in this article for kids.

Read More

Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.