IgA Vasculitis

What is IgA Vasculitis?

IgA vasculitis is a disorder that causes inflammation in small blood vessels. It happens when an antibody called immunoglobulin A, or IgA, builds up in blood vessel walls. This buildup leads to swelling and irritation that can affect your skin, joints, digestive system, and kidneys.

This condition was previously known as Henoch-Schönlein purpura, or HSP. It most commonly affects children between ages 2 and 6, but adults can develop it too. The condition typically appears after a respiratory infection, like a cold or strep throat. Most people recover fully within a few weeks to months, though some may experience recurring episodes.

The most recognizable sign of IgA vasculitis is a distinctive rash that looks like raised purple or red spots. These spots appear when tiny blood vessels under the skin become inflamed and leak blood. The rash usually starts on the legs and buttocks but can spread to other areas. While the condition can be alarming, most cases resolve on their own with supportive care.

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Symptoms

Raised purple or red spots on the skin, especially on legs and buttocks
Joint pain and swelling, most often in knees and ankles
Abdominal pain and cramping
Nausea and vomiting
Blood in the stool or dark, tarry stools
Swelling in the legs, feet, or scrotum
Fever
Headache
Fatigue
Blood or protein in the urine

The rash is usually the first symptom to appear, though some people develop joint or abdominal pain first. Kidney problems may not cause obvious symptoms early on, which is why urine testing is important during diagnosis and follow-up.

Causes and risk factors

The exact cause of IgA vasculitis is not fully understood. Researchers believe it happens when the immune system responds abnormally to an infection or other trigger. This abnormal response causes IgA antibodies to deposit in blood vessel walls, leading to inflammation. About half of all cases occur within one to three weeks after an upper respiratory infection, like a cold, flu, or strep throat. Other triggers may include certain medications, foods, insect bites, or vaccinations, though these are less common.

Several factors may increase your risk of developing IgA vasculitis. The condition is more common in children, particularly boys, than in adults. It occurs most often during fall and winter months, possibly because respiratory infections are more frequent then. Genetic factors may play a role, as the condition can run in families. Adults who develop IgA vasculitis may have more severe symptoms and a higher risk of kidney complications compared to children.

How it's diagnosed

Doctors typically diagnose IgA vasculitis based on physical examination and symptoms, particularly the distinctive rash. Blood tests may be ordered to check for inflammation and rule out other conditions. Immunoglobulin A levels can be measured, though they may be normal or only slightly elevated in many cases. Other blood tests help assess kidney and liver function and check for signs of infection or inflammation.

Urine tests are important to check for blood or protein in the urine, which can indicate kidney involvement. In some cases, a skin biopsy may be performed to confirm the diagnosis. The biopsy shows IgA deposits in small blood vessel walls. If kidney problems are suspected, a kidney biopsy may be recommended to assess the extent of damage. Talk to your doctor about which tests are right for your situation. They can help coordinate specialized testing and monitor your condition over time.

Treatment options

Rest and supportive care while the condition resolves on its own
Over-the-counter pain relievers like acetaminophen for joint pain and fever
Staying well hydrated, especially if experiencing digestive symptoms
Monitoring urine for blood or protein to track kidney function
Corticosteroid medications like prednisone for severe abdominal pain or kidney problems
Immunosuppressive medications for severe kidney involvement
Blood pressure medications if kidney problems develop
Avoiding medications that may have triggered the condition
Regular follow-up with your doctor to monitor for complications

Frequently asked questions

They are the same condition. The medical community renamed Henoch-Schönlein purpura to IgA vasculitis in 2012 to better describe what happens in the disease. The new name reflects the fact that immunoglobulin A deposits cause the blood vessel inflammation. You may still hear doctors use both names interchangeably.

No, IgA vasculitis itself is not contagious and cannot spread from person to person. However, the infections that sometimes trigger the condition, like colds or strep throat, are contagious. If someone develops IgA vasculitis after an infection, others who catch the same infection will not automatically develop vasculitis. The condition requires a specific immune response that most people do not have.

Most cases of IgA vasculitis resolve within four to six weeks without treatment. Some people experience symptoms for several months. About one-third of patients have one or more recurrences, usually within the first four months after the initial episode. Children typically recover faster and more completely than adults.

Most people with IgA vasculitis do not develop permanent kidney damage. However, kidney problems occur in about 20 to 60 percent of cases, ranging from mild to severe. Adults are at higher risk than children for developing chronic kidney disease. Regular monitoring of urine and kidney function is important, especially in the first six months after diagnosis.

There are no specific foods that everyone with IgA vasculitis must avoid. Some people report that certain foods triggered their initial episode, but this varies by individual. If you have abdominal symptoms, your doctor may recommend a bland diet until your digestive system heals. Stay well hydrated and maintain balanced nutrition to support your recovery.

Adults can definitely develop IgA vasculitis, though it is less common than in children. About 10 percent of cases occur in adults. Adults tend to experience more severe symptoms and have a higher risk of kidney complications and chronic kidney disease. The treatment approach is similar for adults and children, though adults may need more aggressive therapy.

The rash from IgA vasculitis typically does not leave permanent scars. The purple or red spots may take several weeks to fade completely. Some people notice temporary skin discoloration that gradually disappears. In rare cases of severe skin involvement, scarring can occur, but this is uncommon with proper care.

Most people with IgA vasculitis can be treated at home with rest and supportive care. Hospitalization may be needed if you have severe abdominal pain, significant kidney problems, or complications. Children who cannot eat or drink due to abdominal pain may need intravenous fluids. Your doctor will determine the appropriate level of care based on your symptoms.

Yes, IgA vasculitis can recur in about one-third of patients. Recurrences usually happen within four to six months of the initial episode but can occur later. Repeat episodes are typically milder than the first. Continuing to monitor urine for signs of kidney problems is important even after symptoms resolve, as kidney issues can develop or worsen during recurrences.

The long-term outlook for IgA vasculitis is generally good, especially in children. Most people recover completely without lasting problems. The main concern is kidney damage, which affects a small percentage of patients. Regular follow-up for at least six months to one year after diagnosis helps catch any delayed kidney problems. Adults should continue monitoring longer due to higher risk of chronic issues.