Henoch Schonlein Purpura (IgA Vasculitis)

Medically Reviewed by Shruthi N, MD on July 15, 2024
Written by Stephanie Watson
7 min read

Henoch-Schönlein purpura (HSP) is a disease that inflames small blood vessels. The inflammation causes blood vessels in the skin, intestines, kidneys, and joints to start leaking. The main symptom is a raised rash with many small bruises on your legs or buttocks.

HSP got its name from two doctors, Eduard Henoch and Johann Lukas Schönlein, who researched this condition in the late 1800s. In 2012, a group of scientists renamed the disease immunoglobulin A (IgA) vasculitis because of the discovery that the antibody IgA causes small blood vessels to leak. 

Although people of any age can get HSP, the disease most often affects children ages 3 to 10. It is more common in boys than girls. Adults with HSP tend to have more severe disease than children do.

Usually, IgA vasculitis goes away on its own after 4 weeks. Within 6 months, the disease comes back in about 1/3 of people, but it usually doesn’t cause long-term problems. Rarely, it causes kidney disease. It’s important to have regular follow-up visits with a doctor if you or your child has IgA vasculitis to prevent serious complications.

 

Doctors don’t know exactly what causes HSP. They think it’s an autoimmune disease, meaning the body attacks itself. IgA is an antibody that normally fights infections. In HSP, it causes the blood vessels to become inflamed. 

An abnormal immune response to an infection may be a factor in many cases. In 3 out of 4 people with IgA vasculitis, symptoms appear after an upper respiratory tract infection like a cold or the flu. It also affects children who’ve had infections like Epstein-Barr and chickenpox. Certain genes may increase the risk.

Other possible causes include: 

  • Reactions to certain foods
  • Insect bites
  • Medicines
  • Certain vaccines 
  • Exposure to cold weather

HSP and COVID-19

Viruses are a likely cause of HSP. Often this condition appears after a virus like group A strep. A few people have developed HSP after a COVID infection or the COVID-19 vaccine.

Researchers don’t know the exact link between IgA vasculitis and COVID. It’s possible that the COVID virus directly damages blood vessels. Or the immune system might overreact to the virus and inflame the blood vessels. Getting IgA vasculitis after a COVID infection or vaccine is very rare, and scientists still need to learn more about the possible connection. 

Because HSP can cause kidney damage, it’s important to get quick treatment if you see bruises after a COVID infection. HSP should clear up quickly with anti-inflammatory medicines called corticosteroids.

The classic symptoms of HSP are a rash, joint pain and swelling, and belly pain. People who have kidney disease may also have symptoms like blood in the urine. 

Before these symptoms begin, you may have a few weeks of fever, headache, and muscle aches and pains. Rarely, IgA vasculitis can affect other organs, such as the brain, lungs, or spinal cord.

Here are some common symptoms of HSP:

Henoch-Schönlein purpura rash. A rash is the symptom that everyone with HSP has. Small red or purple bruises or spots pop up mainly on the lower legs, buttocks, and feet, but sometimes also on the elbows, arms, and trunk. The spots look like bruises. The rash will not turn white if you press on it.

Arthritis. About 75% of children with IgA vasculitis have joint pain and swelling. Arthritis is most often in the joints of the knees, ankles, hands, and feet. Joint pain usually lasts only a few days and doesn’t cause any long-term problems.

Belly pain. Inflammation in the GI tract can cause belly pain or cramps, nausea, vomiting, and blood in your poop. These symptoms can appear before, at the same time, or after the rash. In rare cases, abnormal folds in the bowel (intussusception) may cause a blockage that could require surgery to fix.

Kidney problems. Protein or blood in the urine on a urine test are signs of kidney damage from HSP. Kidney problems are usually mild and go away without causing any long-term issues. It's important for your doctor to monitor your kidneys closely and make sure any problems clear up. Rarely, HSP can lead to kidney damage and kidney failure that requires dialysis or a kidney transplant.

Does HSP cause purple spots on the skin?

Purple bruise-like spots called purpura are the main symptom of IgA vasculitis. These spots form when the disease damages blood vessels under the skin and makes them leak. The rash can also look like small red spots. 

What is the difference between IgA nephropathy and IgA vasculitis?

IgA nephropathy is another autoimmune disease that involves IgA antibodies. In IgA nephropathy, IgA builds up in the tiny filtering blood vessels inside the kidneys and damages them. This damage makes the kidneys leak blood and protein into the urine. IgA nephropathy can lead to high blood pressure, chronic kidney disease, and eventually kidney failure.

Doctors start the diagnosis with a physical exam, looking for symptoms like a purplish rash, joint pain, and belly pain. These tests can help confirm the diagnosis and rule out other diseases with similar symptoms:

  • Urinalysis. This test shows tiny amounts of blood or protein in the urine, which are signs of kidney damage. 
  • Blood test. A very high level of IgA in the blood is a sign of IgA vasculitis. A blood test can also check for infection.
  • Ultrasound. This test uses sound waves to make pictures of your kidneys. It can show abnormal swelling in your kidneys.
  • Biopsy. In this test, the doctor removes a small piece of skin. A lab checks the skin sample under a microscope for IgA deposits, which are a sign of HSP. A kidney biopsy can confirm the diagnosis. 

Your doctor may repeat urine and blood tests to monitor you for changes in kidney function.

Glass test for HSP

The HSP rash should not disappear or turn white when you press on it. One way to check is with the glass test. Press the side of a clear glass firmly against the skin over the rash. If you can still see the spots through the glass, it could be HSP.

There is no specific treatment for IgA vasculitis. The rash should go away on its own within 2 months. Your doctor may prescribe antibiotics if a bacterial infection could have caused IgA vasculitis. 

Until HSP goes away, these treatments can help with specific symptoms:

Joint pain: Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and naproxen relieve joint pain and swelling. Don’t take these medicines if you have kidney damage because they can make it worse. Acetaminophen (Tylenol) also helps with joint pain and it’s safer on the kidneys. Corticosteroids are prescription medicines that treat joint inflammation.

Belly pain: Corticosteroids are also a treatment for severe abdominal pain.

Kidney problems: Corticosteroids or other medicines that suppress the immune system can reduce inflammation in the kidneys. Blood pressure-lowering drugs called angiotensin-converting enzyme (ACE) inhibitors or angiotensin-receptor blockers (ARBs) help to slow kidney damage.

How is Henoch-Schönlein purpura in children treated?

HSP often goes away on its own without any treatment. In children whose condition doesn’t improve, treatment depends on their age, health, and the severity of the condition. Possible treatments include:

  • Pain relievers like NSAIDs or Tylenol to relieve sore joints and belly pain
  • Extra fluids to keep them hydrated
  • Corticosteroids to treat joint pain and swelling, belly pain, and kidney problems
  • Medicine to lower blood pressure
  • Medicine to suppress the overactive immune system
  • Supplements such as fish oil and antioxidants

In 94% of children and 89% of adults with IgA vasculitis, the disease goes away on its own. The rash and joint pain usually disappear after 4 weeks without causing any permanent damage. The rash comes back in one out of three people with IgA vasculitis within 4 to 6 months. Usually this rash is milder, there aren’t any joint and abdominal symptoms, and symptoms clear up on their own.

HSP affects many parts of the body. In rare cases, it causes complications like:

  • Kidney disease
  • Kidney failure
  • Bowel folding (intussusception)
  • GI bleeding
  • Bowel blockage
  • Bleeding in the brain
  • Seizures
  • Nerve damage
  • Fluid or bleeding in the lungs
  • Twisting of the testicles (testicular torsion)

Call your doctor if you have reddish-purple spots on your body or any other symptoms of HSP, especially if they happen after an upper respiratory infection. After you’ve had HSP, your doctor should monitor you with regular follow-up visits and tests. Call the doctor right away if your symptoms come back or you have new symptoms. 

Henoch-Schönlein purpura (HSP) is a disease that inflames blood vessels and causes bruise-like rashes to form on the body. The new name for HSP is IgA vasculitis. Pain relievers, corticosteroids, and other treatments can manage symptoms until the condition improves, which usually takes about 4 weeks.

Is HSP an autoimmune disease?

Yes. HSP is an autoimmune disease. It often happens after an infection like a cold or the flu. The immune system overreacts and damages blood vessels in many parts of the body.

What is the triad of Henoch-Schönlein purpura?

The “triad” refers to three classic symptoms of HSP: red or purple bruises under the skin, belly pain, and joint pain.

What is the hallmark of Henoch-Schönlein purpura?

The hallmark symptom of HSP is a bruise-like rash on the legs and other parts of the body.

What are risk factors for Henoch-Schönlein purpura?

Most people develop HSP after an upper respiratory or GI infection. Other possible risk factors include medicines, reactions to food, bug bites, and vaccines.