Key points to remember about Henoch-Schonlein purpura

Most children with HSP make a full recovery.

• Henoch-Schonlein purpura (HSP) causes inflammation of the small blood vessels in the skin causing a rash
• HSP can also affect blood vessels around the kidneys and intestines
• HSP can cause joint pain
• HSP happens most often in children from 2 to 10 years of age
• you cannot catch HSP from another person
• return to your doctor if there is increasing pain, swelling, blood in your child's poo or wee
• most children with HSP make a full recovery

What is Henoch-Schonlein purpura?

HSP is due to blood vessels becoming inflamed. This inflammation is called vasculitis. The vasculitis affects the small blood vessels in the skin, causing a rash (red or purple spots called purpura). It can also affect blood vessels around the joints, in the intestines and in the kidneys.

What causes Henoch-Schonlein purpura?

The cause of HSP is unknown. It might be triggered by bacterial or viral infections, medicines, insect bites or exposure to chemicals or cold weather. It occurs most often in the spring, usually after an upper respiratory infection, like a cold.

HSP usually affects children from 2 to 10 years of age, but it can happen in anyone. You can't catch HSP. 

What are the signs and symptoms of Henoch-Schonlein purpura?

Skin rash

This may start out looking like red spots, bumps or raised skin welts which can be itchy. This quickly changes to small bruises or reddish-purple spots that are often raised. It usually appears on the buttocks, on the legs and around the elbows. Blisters and/or ulcers may develop in the affected areas.

The rash looks the same as the rash children with meningococcal disease can get. So, if your child has a fever with this rash, call an ambulance.

Pain and swelling in the joints

Pain and swelling in the joints (such as the knees and ankles) which can come and go and can move around from joint to joint.

Tummy pain

This can come and go and in some cases can be severe. 

Blood in the poo

This is caused by the blood vessels in the bowel becoming inflamed and can indicate more serious problems (such as an abnormal folding of the bowel called intussusception [1]).

Blood in the wee

This is caused by the blood vessels in the kidney becoming inflamed (irritated and swollen). Serious kidney problems don't happen very often, but they can occur.

Swelling

Many children with HSP also have swelling over the backs of their feet and hands, and the scrotum in boys.

How is Henoch-Schonlein purpura diagnosed?

There is no specific laboratory test for the disease. Your doctor will diagnose HSP after looking at your child's signs and symptoms. Your doctor may order blood tests to exclude other conditions. If HSP is suspected, your child will have urine tests to look for possible kidney involvement.

What is the treatment for Henoch-Schonlein purpura?

Fortunately, HSP usually gets better without any treatment. Pain relief (such as paracetamol) can help the joint pain. You must follow the dosage instructions on the bottle. It is dangerous to give more than the recommended dose.

Your doctor may recommend a drug called prednisolone. This can help people with severe stomach pains or very painful joints.

How long does Henoch-Schonlein purpura last?

The illness lasts 4 to 6 weeks in most patients. The rash (purpura) changes from red to purple, becomes rust-coloured and then fades completely.

About 3 in 10 of those with HSP can get it again, usually within 4 months of the initial illness. Repeat episodes of the illness are usually milder and shorter and more common in patients with kidney involvement. 

What are the complications of Henoch-Schonlein purpura?

Your doctor will want to check urine samples and blood pressure several times after the HSP goes away to check for kidney problems.

Most people with HSP get better over time without treatment and have no long-term problems. About 5 in 100 of those with HSP develop long-term kidney disease (called glomerulonephritis). This may occur in the first week or so of the illness, but there may be a delay of weeks or months before it appears.

Your doctor will want to check urine samples and blood pressure several times after the HSP goes away to check for kidney problems. These checks should go on for at least 6 months and some doctors recommend a blood pressure and urine check every year for life.

When should I seek help for my child with Henoch-Schonlein purpura?

Return to your doctor or the hospital if your child has one or more of the following or if you are worried for any other reason:

• increasing tummy pains
• swelling and pain that is not responding to pain relief
• blood in the poo or wee