Immunoglobulin A (IgA) vasculitis

Immunoglobulin A vasculitis, also known as IgA vasculitis, affects the small blood vessels (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.

It can also affect adults, but most of the 2,500 new cases a year in the UK are children.

The symptoms of IgA vasculitis 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.

The rash seen in IgA vasculitis is called purpura and was described by doctors Henoch and Schonlein, which explains the previous name of the disease.

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.

Find out more about vasculitis.