Henoch-Schonlein Purpura
IgA vasculitis, Anaphylactoid purpura, Purpura rheumatica
Henoch-Schonlein purpura is a condition that causes inflammation of small blood vessels, leading to a distinctive rash and other symptoms. While it most commonly affects children between ages 2 and 10, it can occur at any age and usually resolves on its own within a few weeks.
Table of contents
- What is Henoch-Schonlein purpura?
- What causes this condition?
- Who gets Henoch-Schonlein purpura?
- Signs and symptoms
- How is it diagnosed?
- Treatment and care
- Follow-up and monitoring
- What to expect
What is Henoch-Schonlein purpura?
Henoch-Schonlein purpura, now also called IgA vasculitis, is a condition that causes inflammation of small blood vessels in the body. This inflammation is called vasculitis. When blood vessels become swollen and irritated, they can leak blood cells into the surrounding tissues[1].
The condition most commonly affects small blood vessels in the skin, joints, intestines, and kidneys. In rare cases, it can also affect the lungs or the brain and spinal cord, though this is extremely uncommon[2].
The name comes from two German physicians, Dr. Johann Schonlein and his student Eduard Henoch, who identified key features of the disease in the 1800s. Schonlein recognized the connection between joint pain and a particular type of rash, while Henoch identified that the condition could also affect the digestive system and kidneys[3].
What causes this condition?
The exact cause of Henoch-Schonlein purpura is not fully understood. It is an autoimmune disorder, which means the body’s immune system mistakenly attacks its own healthy cells and organs[5].
In this condition, a protein called immunoglobulin A (IgA) that normally helps fight infections gets deposited in the walls of small blood vessels. This leads to inflammation and causes the blood vessels to become swollen and leaky[3].
The condition is often triggered by something that activates the immune system. The most common trigger is an upper respiratory infection, such as a cold or sore throat. About half of all cases follow such an infection, typically appearing about 1 to 2 weeks after the respiratory symptoms begin[8].
Other possible triggers include viral or bacterial infections such as group A streptococcus, food allergies, certain medications, insect bites, vaccinations, or exposure to cold weather. However, in many cases, no specific trigger can be identified[1][19].
It’s important to note that Henoch-Schonlein purpura itself is not contagious, even though the infection that may have triggered it might be contagious. There is no known way to prevent the condition[2].
Who gets Henoch-Schonlein purpura?
Henoch-Schonlein purpura can affect anyone at any age, but it is most common in children. More than 90 percent of cases occur in children younger than 10 years, with the peak age being around 5 to 6 years[8].
The condition occurs about twice as often in boys as in girls[3][8]. Among children, those between ages 2 and 10 are most commonly affected, though it can also occur in infants, adolescents, and adults[2].
In North America, Henoch-Schonlein purpura is the most common form of vasculitis in children, affecting approximately 10 to 22 people per 100,000 each year[8]. The condition occurs most frequently in the spring, fall, and winter months[2][8].
When the condition occurs in adults, it tends to be more severe and is more likely to cause long-term complications, particularly affecting the kidneys. Children younger than 2 years tend to have milder symptoms[1][8].
Signs and symptoms
The symptoms of Henoch-Schonlein purpura can develop suddenly or gradually over days to weeks. They may appear in any order, and not all symptoms occur in every person[2].
The rash
The most distinctive feature of Henoch-Schonlein purpura is a characteristic rash that occurs in all cases. The rash consists of raised red or purple spots called purpura that look like small bruises or blood spots. These spots do not fade or become lighter when you press on them with a finger or a glass[1][4].
The rash typically appears on the legs and buttocks, but it can also affect the arms, face, chest, back, and belly. It tends to be worse in areas where clothing puts pressure on the skin, such as the sock line and waistline. In younger children who are not yet walking, the rash may appear more often on the face, trunk, and upper body[1][10].
The rash usually starts as red or pink raised bumps and then progresses to purple spots. Over time, these spots change color from red to purple, then to a rust color with a brownish hue, and finally fade away. There may be many spots or just a few[4].
Joint pain and swelling
About 50 to 75 percent of people with Henoch-Schonlein purpura experience joint pain and swelling. The joints most commonly affected are the knees and ankles, though the elbows, wrists, and other joints can also be involved[1][8].
The joint pain often develops about 1 to 2 weeks before the rash appears, though it can occur at any time during the illness. The affected joints may be warm, tender, and swollen. However, the joint inflammation does not cause permanent damage or deformity[1][6].
Abdominal symptoms
Stomach pain is common, affecting about 50 to 65 percent of people with Henoch-Schonlein purpura. The pain is often crampy or colicky in nature and can be severe. It may be accompanied by nausea, vomiting, and diarrhea[1][8].
Blood may appear in the stools, either visible to the eye or detected only through laboratory testing. In some cases, there may also be vomiting of blood. The abdominal pain typically resolves within a few days in most cases[1][4].
A rare but serious complication is a condition called intussusception, where one part of the intestine slides into another part, causing a blockage. This may require surgical treatment[2].
Kidney involvement
About 25 to 50 percent of people with Henoch-Schonlein purpura develop some degree of kidney involvement. In most cases, this is mild and causes no noticeable symptoms. It is usually detected only through urine tests that show small amounts of blood or protein in the urine[1][8].
Kidney problems may appear during the first week of illness, but they can also develop weeks or months later. This is why regular monitoring of urine and blood pressure is important even after other symptoms have resolved[2].
Other symptoms
Additional symptoms may include swelling under the skin, particularly in the hands, feet, and scrotum in boys. Some people may also experience headache, low-grade fever, fatigue, and a general feeling of being unwell[1][8].
How is it diagnosed?
Henoch-Schonlein purpura is usually diagnosed based on its characteristic symptoms, particularly the distinctive rash combined with other features such as joint pain, abdominal pain, or signs of kidney involvement[11].
Your doctor will begin by taking a detailed medical history and performing a physical examination. They will ask about recent illnesses, medications, and any other symptoms you or your child may be experiencing[5].
Urine and blood tests
Urine tests are essential for checking whether the kidneys are affected. These tests look for blood or protein in the urine. Blood tests may be performed to check kidney function and to rule out other conditions[11][5].
There is no single laboratory test that can confirm Henoch-Schonlein purpura. However, blood tests can help rule out other conditions that might cause similar symptoms[11].
Biopsy
If the diagnosis is unclear, a doctor may take a small sample of skin tissue to examine under a microscope. This procedure is called a biopsy. In Henoch-Schonlein purpura, the biopsy typically shows deposits of IgA protein in the walls of the small blood vessels[11][3].
In cases of severe kidney involvement, a kidney biopsy may be needed to assess the extent of kidney damage and guide treatment decisions[11].
Imaging tests
An ultrasound may be performed to examine the abdomen, especially if there is severe abdominal pain. This imaging test uses sound waves to create pictures of the internal organs and can help rule out other causes of abdominal pain or identify complications such as intussusception[11][5].
Treatment and care
In most cases, Henoch-Schonlein purpura resolves on its own within several weeks without specific treatment. The main approach is supportive care to help manage symptoms and make the person more comfortable[11][13].
Home care
Rest and adequate fluid intake are important parts of recovery. For mild pain, over-the-counter pain relievers such as paracetamol (acetaminophen) can be used. Your doctor may also recommend anti-inflammatory medications such as ibuprofen or naproxen for joint pain, as long as there are no contraindications such as stomach bleeding or kidney problems[2][4].
Elevating swollen areas, such as the legs or arms, can help reduce swelling and discomfort[18].
Medications
If joint pain or abdominal pain is severe, your doctor may prescribe corticosteroid medications such as prednisolone or prednisone. These medications help reduce inflammation and can ease severe pain. Studies have shown that steroids can reduce the duration of abdominal pain and may decrease the risk of developing persistent kidney problems[8][11].
The typical dose is 1 to 2 mg per kilogram of body weight per day, up to a maximum of 60 mg per day. Treatment usually continues while symptoms persist, followed by a gradual reduction in dose. Because these medications can have side effects, your doctor will carefully weigh the benefits and risks[11][18].
In cases of severe kidney involvement, more aggressive treatment with high-dose steroids plus other medications that suppress the immune system may be needed[8][13].
Hospital care
Admission to the hospital may be necessary if there is severe abdominal pain, significant bleeding in the digestive tract, or serious kidney problems. In the hospital, stronger pain medications and intravenous fluids may be given. Close monitoring helps detect any complications early[13][4].
Follow-up and monitoring
Regular follow-up is crucial even after symptoms have improved. About 50 percent of children who have had Henoch-Schonlein purpura will experience a recurrence of symptoms, though repeat episodes are usually less severe than the first one. Recurrent episodes can occur for up to a year after the initial diagnosis[2][12].
Because kidney problems can develop or worsen weeks or months after the initial illness, ongoing monitoring is essential. Your doctor will want to check urine samples and measure blood pressure regularly for at least 6 months after the diagnosis. A final check is typically recommended at 12 months[2][4].
If you notice any new symptoms, such as increasing pain or swelling, blood in the urine or stools, high blood pressure, or any other concerning changes, contact your doctor promptly[4].
What to expect
The outlook for most people with Henoch-Schonlein purpura is very good. In children, the condition resolves completely in about 94 percent of cases, and in adults, about 89 percent fully recover[8].
Most people recover completely within several weeks without any lasting problems. The rash and joint pain typically disappear within a few weeks, while abdominal pain usually resolves even sooner, often within 3 days[1][22].
The most serious potential complication is kidney damage. While most kidney involvement is mild and temporary, a small percentage of people may develop chronic kidney disease. Serious kidney problems occur in only about 1 to 5 percent of all cases[8][4].
The long-term outlook depends primarily on the severity of kidney involvement. Children with signs of kidney problems at the start of the illness, particularly those with significant protein in the urine or high blood pressure, require closer monitoring[13].
Once symptoms have resolved and your child feels well, they can return to normal activities, including school and sports. The condition does not typically cause permanent damage to the joints or intestines[4][17].
