Henoch Schönlein purpura (HSP) is a disease where small blood vessels called capillaries become inflamed and damaged, producing a rash on the skin called ’purpura’.
We do not know exactly what causes HSP, but it seems to follow on from some viral or bacterial infections such as a cold or respiratory tract infection. HSP is not an inherited disease and is not contagious.
It is named after the doctors who first described the disease and is often referred to as HSP for short. Children between the ages of 2 and 11 years old seem to develop HSP more than younger or older children, and it seems to affect slightly higher numbers of boys than girls.
What are the symptoms?
The symptoms mainly affect four areas of the body and can come and go for several weeks or even months in some cases:
- Affected in all cases
- A purple-red rash, which does not turn white when pressed.
- In some cases this rash can turn into ulcers
- The rash is usually over the backs of the limbs, especially the legs, which can also be swollen
- Tummy aches and pains which can be severe and occasionally result in blood in the stool
- Painful and swollen joints can occur due to inflammation, usually affecting the knees and ankles
- Protein and blood may be found in the urine due to inflammation in the kidneys. Often this will resolve as your child gets better but can be a more serious long-term problem and will need careful monitoring
How is it diagnosed?
HSP is usually diagnosed by looking at your child’s history of symptoms and with a physical examination. They will often need a blood test and urine test. If there is a lot of blood and protein in the urine, very high blood pressure, or other blood test markers of kidney damage, a kidney biopsy will be required. This is rarely needed, however.
How is it treated?
There is no specific treatment for HSP other than rest and recuperation, and symptoms usually go away within several weeks. Paracetamol or ibuprofen can be given to relieve any joint pains. Steroids may be used in children with severe symptoms, particularly bad tummy pain or kidney damage.
What is the outlook for children with HSP?
Overall, HSP does not cause long-term problems and most children make a full recovery, although relapses (usually milder than the first attack) can occur in about half of the children in the following months. Children with kidney involvement may need further investigations and regular longer term reviews by a doctor.