Key points about Henoch-Schonlein purpura
- Henoch-Schonlein purpura (HSP) causes inflammation of the small blood vessels
- a skin rash (purpura) is the most common sign
- HSP can cause joint pain
- HSP can also affect blood vessels in the kidneys and digestive tract
- HSP happens most often in tamariki (children) from 2 to 10 years of age
- go back to your health professional if there is increasing pain or swelling, or blood in your child's poo or wee
- most tamariki with HSP make a full recovery
Most children with HSP make a full recovery.
What is Henoch-Schonlein purpura?
Henoch-Schonlein purpura (HSP) happens when small blood vessels get inflamed. This is called vasculitis. It affects small blood vessels in the skin and causes red or purple spots called purpura. It can also affect blood vessels in the joints, kidneys, and digestive tract.
Causes of Henoch-Schonlein purpura
The cause of HSP is not clear. Possible triggers include:
- viral or bacterial infections
- certain medicines
- exposure to chemicals
- exposure to cold weather
HSP is most common in the spring, usually after a viral infection, like a cold.
HSP usually affects tamariki from 2 to 10 years of age, but it can happen in anyone. You can't catch HSP from another person.
Signs and symptoms of Henoch-Schonlein purpura
An illustration showing the symptoms of Henoch-Schönlein purpura in children.
Source: KidsHealth
transcribeTranscript
The illustration shows a child sitting on the ground with their knees up. Several circular close-ups surround the child and are connected by dashed lines, each showing a symptom of Henoch-Schönlein purpura.
- The top left circle is labelled Tiredness and shows the child’s tired-looking face.
- Next to it, a close-up is labelled Fever and shows the child with a flushed face.
- On the upper right, a circle labelled Rash over the body shows red, spotty patches on the skin.
- To the right of that, a close-up labelled Joint pain and swelling shows swollen joints with pain lines.
- At the bottom right, a circle labelled Swelling over the hands and feet shows puffiness over the feet.
- On the lower left, a close-up labelled Tummy pain shows hands holding the stomach with pain lines.
- Labels are also present for Blood in the poo and Blood in the wee.
At the top right is the KidsHealth logo with the website: kidshealth.org.nz.
Skin rash
This may start out with 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.
The rash usually appears on the buttocks, legs and around the elbows. Your child could get blisters or ulcers where the rash is.
The rash can look the same as a meningococcal disease rash. So, if your child has a fever and a rash, get medical help urgently.
Photographs of the Henoch-Schonlein purpura rash on the feet, legs and buttocks.
Source: DermNet
Pain and swelling in the joints
Pain and swelling can affect the joints, usually the knees and ankles. Some tamariki may refuse to walk or use their hands. The pain may come and go.
Swelling
Many tamariki with HSP have swelling on the backs of their feet and hands. Boys may also have swelling in the scrotum.
Increased blood pressure
Some tamariki may have an increase in their blood pressure. This happens when blood vessels in the kidney become inflamed.
Blood in the wee
When blood vessels in the kidney become inflamed it can lead to blood in the wee.
Tummy pain
Tummy pain can come and go. For some tamariki the pain can be severe.
Blood in the poo
This happens because of inflammation of the blood vessels in the digestive tract.
Blood in the poo can also happen with a condition called intussusception. This is when one part of the bowel folds into another.
Diagnosing Henoch-Schonlein purpura
There’s no specific test for HSP. Your health professional will look at your child’s signs and symptoms. They may do blood tests to rule out other conditions. If they think your child has HSP, they might test your child’s urine to check the kidneys.
Managing Henoch-Schonlein purpura
Pain relief if needed
HSP usually gets better on its own. Pain relief, such as paracetamol, can help with joint pain. Always follow the dosage instructions. It is dangerous to give more than the recommended dose.
Other medicine
Your health professional may also recommend prednisolone. This medicine can help if your child has severe stomach pain or very sore joints.
How long Henoch-Schonlein lasts
HSP usually lasts 4 to 6 weeks in most tamariki. The rash (purpura) changes colour over time. It goes from red to purple, then rust-coloured, and finally fades away.
A small number of tamariki get HSP again, usually within a few months of the first illness. If HSP affects a child’s kidneys, they are more likely to get it again.
Possible complications of Henoch-Schonlein purpura
Your health professional will want to check urine samples and blood pressure several times after the HSP goes away to check for kidney problems.
Most tamariki with HSP get better on their own and have no lasting problems. A small number of tamariki may develop long-term kidney disease, called glomerulonephritis. This can happen in the first week or sometimes weeks or months later.
After your child gets better, your health professional will still do follow-up checks. They will test your child’s urine and blood pressure several times. This helps to find any kidney problems early.
Checks should happen:
- every week for the first month after HSP starts
- every 2 weeks from weeks 5 to 12
- at 6 months and 12 months
If your child gets HSP again, the weekly checks will start again.
You can download the Starship ‘HSP follow-up record’ (PDF, 79 KB) from the Starship website. You can use it to track your child’s follow up checks.
When to get medical help for your child with Henoch-Schonlein purpura
Go back to a health professional if you are worried for any reason. Also see a health professional if your child has any of the following:
- worsening tummy pain
- swelling or pain that doesn’t get better with pain relief
- blood in their poo or wee
Acknowledgements
Illustrations by Dr Greta File. Property of KidsHealth.
Photos of HSP (Henoch-Schonlein purpura) on this page have been reproduced, with permission, from the website of the New Zealand Dermatological Society Incorporated.
