Immunoglobulin A–Associated Vasculitis
(See also Overview of Vasculitis.)
Immunoglobulin A–associated vasculitis (formerly called Henoch-Schönlein purpura) is inflammation of mainly small blood vessels that most often occurs in children.
A rash of reddish purple bumps and spots on the lower legs is usually the first symptom, followed by fever, joint aches, digestive upset, and kidney malfunction.
Biopsy of the affected skin can confirm the diagnosis.
Corticosteroids are sometimes needed to relieve joint aches and digestive upset, but, occasionally, other drugs that suppress the immune system are also needed.
Immunoglobulin A–associated vasculitis usually affects children aged 3 to 15 but can occur at any age. It may develop when the immune system responds abnormally to an infection or something else. It may be triggered by viruses that cause upper respiratory infections, drugs, foods, immunizations, or insect bites. The inflammation typically occurs in blood vessels in the skin, but blood vessels in the intestine and kidney may also become inflamed.
A rash of small spots that look like bruises or reddish purple bumps (purpura) appear on the feet, legs, and, occasionally, the trunk and arms. The rash may at first look like hives that have lumped together. After a few days or weeks, new spots and bumps may appear, sometimes on the trunk too. Most children also have a fever and achy, tender, and swollen joints, including the ankles, knees, hips, wrists, and elbows.
Crampy abdominal pain and tenderness, nausea, vomiting, tarry black stools (melena), and diarrhea are common. Stools or urine may contain blood. Rarely, the intestine slides into itself, like a collapsible telescope. This complication, called intussusception, can cause sudden stomach pain and vomiting because the intestine is blocked.
Symptoms usually resolve after about 4 weeks but often return at least once after a few weeks. Most people recover completely. Rarely, chronic kidney failure develops.
Doctors suspect the disorder when the characteristic rash occurs in children. If the diagnosis is not clear, a sample from the affected skin is taken and examined under a microscope (biopsy) to look for abnormalities in the blood vessels that can confirm the diagnosis. Urine tests are done to check for blood and excess protein, which indicate that the kidneys are affected. Blood tests are usually done to measure kidney function. Doctors ask people whether they have recently been ill, because immunoglobulin A–associated vasculitis may develop after a streptococcal infection.
If kidney malfunction worsens, a kidney biopsy is often done. It can help doctors determine how severe the problem is and what kind of recovery can be expected.
If a drug is causing the disorder, it is stopped. Otherwise, treatment is focused on relieving symptoms.
Corticosteroids, such as prednisone, taken by mouth (orally) may help control abdominal pain and are occasionally needed to help control severe joint pain or swelling or kidney disease. If the kidneys are severely affected, methylprednisolone (a corticosteroid), given by vein (intravenously), and prednisone and cyclophosphamide (which suppresses the immune system), taken orally, may be necessary.