Henoch-Schonlein is caused by an abnormal response of the immune system. It is unclear why this occurs.
The syndrome is usually seen in children, but it may affect people of any age. It is more common in boys than in girls. Many people with Henoch-Schonlein purpura had an upper respiratory illness in the weeks before.
What causes Henoch-Schönlein purpura?
Henoch-Schonlein is caused by an abnormal response of the immune system. It is unclear why this occurs.
The syndrome is usually seen in children, but it may affect people of any age. It is more common in boys than in girls. Many people with Henoch-Schonlein purpura had an upper respiratory illness in the weeks before.