Henoch-Schonlein Purpura

Henoch–Schönlein purpura, also known as IgA vasculitis, is a condition that causes inflammation of small blood vessels, called vasculitis. This inflammation leads to bleeding into the skin, joints, intestines and kidneys. The condition most commonly affects children, but it can also occur in adults and may be more severe in older individuals.

Henoch–Schönlein purpura often develops after a respiratory infection, such as a cold or sore throat. The condition is linked to abnormal immune system activity, in which a type of antibody called immunoglobulin A builds up in blood vessel walls. This immune reaction causes swelling, irritation and leakage from the blood vessels.

Most cases resolve on their own with supportive care, but some people may develop complications, particularly involving the kidneys, that require close monitoring and treatment.

Symptoms

Symptoms of Henoch–Schönlein purpura can vary in severity and may appear over days or weeks. The most recognizable symptom is a purplish rash.

Common symptoms include:

• Purplish-red rash, usually on the legs, buttocks or lower body

• Joint pain and swelling, especially in the knees and ankles

• Belly pain that may be severe

• Nausea or vomiting

• Blood in the stool or dark-colored stools

• Blood or protein in the urine

• Swelling of the hands, feet or face

In children, symptoms often improve within several weeks. Adults may experience longer-lasting or more severe symptoms.

Causes

The exact cause of Henoch–Schönlein purpura is not fully understood. It is believed to be triggered by an abnormal immune response.

Possible triggers include:

• Upper respiratory infections

• Viral or bacterial infections

• Certain medications

• Insect bites

• Vaccinations, in rare cases

These triggers may cause the immune system to produce excess IgA antibodies, which then deposit in small blood vessels and lead to inflammation.

Risk factors

Factors that may increase the risk of developing Henoch–Schönlein purpura include:

• Age, most commonly affecting children between 2 and 10 years

• Male sex

• Recent respiratory infection

• Cold weather, as cases are more common in fall and winter

Although less common, adults with the condition are more likely to experience kidney complications.

Complications

Most people recover fully from Henoch–Schönlein purpura, but complications can occur, particularly involving the kidneys.

Possible complications include:

• Kidney inflammation that may lead to long-term kidney damage

• Intestinal bleeding

• Bowel obstruction or intussusception, especially in children

• High blood pressure related to kidney involvement

Regular follow-up may be needed to monitor kidney function, especially if urine abnormalities persist.

Prevention

There is no guaranteed way to prevent Henoch–Schönlein purpura because the exact cause is unknown. However, reducing exposure to common triggers may lower risk.

Preventive measures include:

• Prompt treatment of infections

• Following prescribed medication instructions carefully

• Monitoring symptoms after infections in children

Early medical evaluation and follow-up help reduce the risk of complications and ensure proper recovery.