Henoch-Schonlein purpura (HEN-awk SHURN-line PUR-pu-ruh) is a disorder that causes inflammation and bleeding in the small blood vessels in your skin, joints, intestines and kidneys.
The most striking feature of Henoch-Schonlein purura is a purplish rash, typically on the lower legs and buttocks. Henoch-Schonlein purpura can also cause abdominal pain and aching joints. Rarely serious kidney damage can occur.
Although Henoch-Schonlein purpura can affect anyone, it's most common in children between the ages of 2 and 6. Henoch-Schonlein purpura usually improves on its own. Medical care is generally needed if the disorder affects the kidneys.
There are four main characteristics of Henoch-Schonlein purpura, although not everyone with the disease develops all four. They include:
- Rash (purpura). Reddish-purple spots, which look like bruises, are the most distinctive and universal sign of Henoch-Schonlein purpura. The rash develops mainly on the buttocks, legs and feet, but it can also appear on the arms, face and trunk and may be worse in areas of pressure, such as the sock line and waistline.
- Swollen, sore joints (arthritis). People with Henoch-Schonlein purpura often have painful, swollen joints — mainly in the knees and ankles. Joint pain sometimes precedes the classical rash by one or two days. These symptoms subside when the disease clears and leave no lasting damage.
- Gastrointestinal symptoms. Many children with Henoch-Schonlein purpura develop gastrointestinal symptoms, such as abdominal pain, nausea, vomiting or bloody stools. These symptoms sometimes occur before the rash appears.
- Kidney involvement. Henoch-Schonlein purpura can also affect the kidneys. In most cases, this shows up as protein or blood in the urine, which you may not even know is there unless you have a urine test done. Usually this goes away once the illness passes, but in a few cases, kidney disease may develop and even persist.
When to see a doctor
In some cases, Henoch-Schonlein purpura causes serious problems of the bowel or kidneys. See your doctor as soon as possible if you or your child develops the distinctive rash associated with Henoch-Schonlein purpura.
In Henoch-Schonlein purpura, some of the body's small blood vessels become inflamed, which can cause bleeding in the skin, joints, abdomen and kidneys. Why this initial inflammation develops isn't clear, although it may be the result of an overzealous immune system responding inappropriately to certain triggers.
Nearly half the people who have Henoch-Schonlein purpura developed the disease after an upper respiratory infection, such as a cold. Infectious triggers may include chickenpox, strep throat, measles and hepatitis. Other triggers may include certain medications, food, insect bites or exposure to cold weather.
Factors that may increase the risk of developing Henoch-Schonlein purpura include:
- Age. The disease affects primarily children and young adults with the majority of cases occurring in children between 2 and 6 years of age.
- Sex. Henoch-Schonlein purpura is slightly more common in boys than girls.
- Race. White and Asian children are more likely to develop Henoch-Schonlein purpura than black children are.
- Time of year. Henoch-Schonlein purpura strikes mainly in autumn, winter and spring but rarely in summer.
For most people, symptoms improve within a month, leaving no lasting problems. Recurrences are fairly common, however.
Complications associated with Henoch-Schonlein purpura include:
- Kidney damage. The most serious complication of Henoch-Schonlein purpura is kidney damage. Occasionally the damage is severe enough that dialysis or a kidney transplant may be needed.
- Bowel obstruction. In rare cases, Henoch-Schonlein purpura can cause intussusception — a condition in which a section of the bowel folds into itself like a telescope, which prevents matter from moving through the bowel.
You'll likely see your family doctor or your child's pediatrician for this condition, although you may be referred to a kidney specialist (nephrologist) if kidney complications develop. Here's some information that may help you get ready for your appointment and what to expect from your doctor.
Before your appointment, you may want to write a list of answers to the following questions:
- When did the symptoms begin?
- Did they come on suddenly or gradually?
- Were you or was your child sick before the rash started?
- What medications and supplements do you or your child take regularly?
Questions you may want to ask your doctor include:
- What might be causing these symptoms?
- What tests are needed to confirm the diagnosis?
- Is this condition temporary or chronic?
- How will I know if there's kidney damage? What if it turns up later on?
- How is Henoch-Schonlein purpura treated?
- What are the side effects of treatment?
- Do you have any literature on this condition? Is there a website you can recommend where I can learn more?
What to expect from your doctor
Your doctor is likely to ask a number of questions, such as:
- What did the rash look like when it first started?
- Is the rash painful? Does it itch?
- Do you or does your child have other symptoms, such as stomach pain or joint aches?
A diagnosis of Henoch-Schonlein purpura is fairly easy to make if the classic rash, joint pain and gastrointestinal symptoms are present. If some of these signs and symptoms are missing, your doctor may suggest one or more of the following tests.
Although no single test can confirm Henoch-Schonlein purpura, certain tests can help rule out other diseases and make a diagnosis of Henoch-Schonlein seem likely. They may include:
- Blood tests. People who have Henoch-Schonlein purpura often have abnormal levels of a particular type of antibody in their blood.
- Urine tests. Your urine may be tested for evidence of blood and to determine if your kidneys are still working properly.
If there are doubts about the rash or if other tests are inconclusive, your doctor may take a small sample of skin to be examined under a microscope. In cases of severe kidney involvement, your doctor may suggest a kidney biopsy to help guide treatment decisions.
Your doctor may recommend an ultrasound to rule out other causes of abdominal pain and to check for possible complications, such as a bowel obstruction.
Henoch-Schonlein purpura usually improves on its own within a month with no lasting ill effects. Bed rest, plenty of fluids and over-the-counter pain relievers may help.
The use of powerful corticosteroids, such as prednisone, in treating or preventing complications of Henoch-Schonlein purpura is controversial. They're most often used to treat severe gastrointestinal symptoms. Because these drugs can have serious side effects and their usefulness isn't clear, be sure to discuss the risks and benefits with your doctor.
If a section of the bowel has folded in upon itself or ruptured, surgical repair will be necessary.
Children and adults with mild Henoch-Schonlein purpura should be kept comfortable while the disease runs its course. Bed rest, plenty of fluids and over-the-counter pain relievers may help.