Henoch–Schönlein purpura (HSP) is a type of vasculitis that affects the capillaries. It often follows a chest infection and may be an allergic reaction to a virus, food or drugs. It mostly affects children aged 2–10 years, and boys are affected more often than girls. However, adults can also be affected.
The symptoms of HSP include:
- a skin rash often over the buttocks (starts red but develops into a bruised purple colour and appears over several days or even weeks)
- short-lived arthritis, especially of the larger joints
- stomach pain and/or vomiting or passing blood in stools
- passing blood in urine (indicating kidney problems)
- fever, headaches and loss of appetite
In most cases the condition doesn’t need specific treatment, although relapses are possible for up to a year after the original illness. Kidney problems are quite common, but serious kidney damage is rare.
Occasionally other blood vessels are involved, and rarely more serious complications can occur, sometimes affecting the bowels or causing seizures.
You can read more about Henoch–Schönlein purpura on our vasculitis pages.