A five-year-old boy presents with a three day history of rash on his legs and a painful right ankle joint for the last 24 hours. The boy’s mother reports that the rash first appeared over both feet and gradually spread to his legs and buttocks. There is no history of fever but he did have an upper respiratory tract infection two weeks before.
On examination, he is afebrile, systemically well with no meningeal signs. He has palpable purpura on his buttocks and legs. His right ankle joint is swollen with painful restricted movements. His blood pressure is 98/46mmHg and urine dipstick shows 1+ protein and 1+ blood.
A presumptive diagnosis of Henoch-Schonlein purpura is made by his GP and he is referred to the local paediatrician.
At the hospital, his baseline blood tests are normal. He is followed up regularly to monitor his clinical condition, blood pressure, renal function, haematuria and proteinuria. After five weeks, the rash has resolved but the boy still has microscopic haematuria and mild proteinuria.
Henoch-Schonlein purpura is the most common systemic vasculitis in childhood. The disease affects small vessels, especially of the skin, bowel and kidneys. It commonly affects children aged five to 15 years.
The aetiology of Henoch-Schonlein purpura is not proven but infectious agents have been postulated as trigger factors, because in about 50% of patients there is history of preceding upper respiratory tract infection.
- Rash – palpable purpura is essential for diagnosis. Skin lesions range from small petechiae to large ecchymoses and are prominent over dependent, or pressure-bearing, areas – especially legs and buttocks.
- Abdominal pain – occurs in about 50% of cases and is periumbilical and colicky. There may be associated vomiting and blood in stools. Massive haemorrhage and intussusception occur in less than 5% of cases.
- Renal disease – renal involvement is seen in about 30 – 35% of patients. Between one and five percent of patients develop end-stage renal failure. Symptoms range from microscopic haematuria, mild proteinuria to nephrotic or nephritic syndrome, and severe renal failure.
- Arthritis and arthralgia – transient joint involvement with pain, swelling and restricted movement is seen in 50% – 80% of cases.
- Less common manifestations include scrotal oedema and pain (in up to 20% of males), and rarely pulmonary and intracranial haemorrhage.
Henoch-Schonlein purpura is a clinical diagnosis. Lab tests help exclude other diagnoses and evaluate renal function. Children may have mild constitutional symptoms. Severe systemic illness should raise suspicion of an alternative diagnosis.
Henoch-Schonlein purpura is a self-limiting disease with an excellent prognosis in most children. Symptoms and signs usually resolve by six weeks. Most do not require any treatment. Recurrence of disease may be seen in 33% of cases. Corticosteroids are indicated in a select few who develop significant organ involvement.
Children are discharged from follow up at six to 12 months in the absence of renal disease or extra-renal manifestations. Patients with persisting renal involvement, albeit mild, are at risk of delayed or progressive renal damage and benefit from long-term surveillance. Renal disease is assessed with regular blood pressure measurements, dipstick of urine and blood tests. The extent and frequency of assessments depend on the severity of disease and local protocols. Persistence of haematuria or proteinuria requires close monitoring. A specialist nephrology opinion should be sought if patients develop nephrotic or nephritic syndrome, hypertension or have asymptomatic urinary sediments beyond 12 months.
Urgent admission to hospital is warranted in the presence of severe abdominal pain, significant gastrointestinal bleeding, marked renal insufficiency or skin ulceration.
Dr Liza McCann is a consultant paediatric rheumatologist and Dr Aruna Bhat is a specialist paediatric registrar in rheumatology, at Alder Hey Children’s Hospital, Liverpool.
Alder Hey is one of Europe’s biggest and busiest children’s hospitals providing care for over 275,000 children and young people each year. Alder Hey has a broad range of hospital and community services for direct referral from primary care. The trust also offers more complex tertiary services – it is the designated national centre for head and face surgery and a centre of excellence for children with cancer, spinal and brain disease. Alder Hey has been chosen to be a national centre for heart surgery, a respiratory ecmo surgery centre and one of just four specialist centres to provide surgery for drug-resistant epilepsy. For more information go to www.alderhey.nhs.uk.
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- Cassidy JT, Petty RE, Laxer RM, Lindsley CB. Textbook of Paediatric Rheumatology. 6th Edition. Philadelphia: Elsevier; 2011.
- Watson L, Richardson ARW, Holt RCL et al. Henoch-Schonlein Purpura – A 5-Year Review and Proposed Pathway. PLoS One 7(1): e29512 doi: 10.1371/journal.pone.0029512