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Health condition · Clinically reviewed

Henoch-Schönlein purpura, the classic tetrad and why the kidneys matter most.

The commonest childhood vasculitis - a purpuric rash, sore joints, abdominal pain and quiet kidney involvement that we watch closely for months.

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Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    Checked against EULAR/PRINTO/PRES, SHARE, BSPAR and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK paediatric rheumatology and nephrology practice, including renal surveillance.

Key facts

HSP at a glance.

The essentials, in plain English - what it is, who it affects and why the kidneys need watching for months, not days.

  • What it is

    IgA vasculitis (formerly Henoch-Schönlein purpura) - small-vessel vasculitis driven by IgA immune-complex deposition in skin, joints, gut and kidneys.

  • Who it affects

    The most common childhood vasculitis, peaking between 3 and 15 years - adult HSP is rarer, tends to be more severe and is linked to renal disease.

  • Trigger

    Often follows an upper-respiratory infection - streptococcal and viral triggers are the best recognised.

  • Classic tetrad

    Palpable purpura on buttocks and legs, joint pain, colicky abdominal pain and renal involvement (haematuria or proteinuria).

  • Prognosis

    Most children recover in 4 to 6 weeks with supportive care - up to 5% develop long-term chronic kidney disease.

  • Follow-up

    Renal surveillance for 6 months - urinalysis and blood pressure - to catch late nephritis early.

Why this guide matters

Reassurance, with the right safety net.

HSP looks alarming and often settles quickly. The three points below shape everything else on this page.

  • Most cases resolve in weeks

    For the majority, HSP is self-limiting in 4 to 6 weeks with supportive care - the goal is comfort and monitoring, not aggressive treatment.

  • The kidneys are the follow-up

    Renal involvement can appear weeks after the rash settles - urinalysis and blood pressure over 6 months is how we catch it early.

  • Severe disease needs a specialist

    Significant nephritis, severe abdominal pain, testicular involvement or adult-onset disease all warrant early specialist review.

How the diagnosis is made

From the first rash to a clear plan.

The steps a UK GP, paediatrician or rheumatologist will normally follow, in order - so you know what to expect and why.

  1. 01

    Assessing

    Recognising the rash

    Non-blanching, palpable purpura on the buttocks and lower limbs is the hallmark - usually dependent and symmetrical.

  2. 02

    Assessing

    Tetrad assessment

    Look for purpura plus one of arthralgia or arthritis, colicky abdominal pain, or renal involvement - the EULAR/PRINTO/PRES criteria.

  3. 03

    Assessing

    Urinalysis and BP

    Every child needs a urine dip and blood pressure at diagnosis - haematuria and proteinuria are the earliest signals of renal involvement.

  4. 04

    Confirming

    Bloods - platelets first

    FBC (normal platelets distinguishes HSP from ITP), coagulation, renal function, inflammatory markers and IgA levels.

  5. 05

    Confirming

    Imaging and stool

    Abdominal ultrasound to exclude intussusception in severe abdominal pain - stool for occult blood if GI symptoms.

  6. 06

    Confirming

    Skin and renal biopsy

    Skin biopsy with immunofluorescence confirms IgA deposition in vessel walls - renal biopsy reserved for significant nephritis, specialist commissioned.

  7. 07

    Preparing

    MDT and follow-up plan

    Specialist paediatric rheumatology and nephrology input for severe cases - 6-month renal surveillance for all.

Typical timeline: rash and diagnosis in days, kidney surveillance across 6 months.

Symptoms

What HSP actually looks like.

The classic tetrad of purpura, joints, gut and kidneys - and the features that mean urgent review.

  • Palpable purpura

    Non-blanching raised purple spots on the buttocks and lower limbs - the defining feature and usually the first sign.

  • Joint pain and swelling

    Large-joint arthralgia or arthritis - knees and ankles most often - transient and non-erosive.

  • Colicky abdominal pain

    Cramping pain, sometimes with vomiting or GI bleeding - warrants review to exclude intussusception.

  • Haematuria and proteinuria

    Renal involvement is often silent - only picked up on urinalysis. Ranges from microscopic haematuria to nephritic or nephrotic syndrome.

  • Scrotal or testicular pain

    Orchitis and scrotal swelling can occur in boys - mimics testicular torsion and needs urgent assessment.

  • Hypertension

    Raised blood pressure signals significant renal involvement and needs prompt investigation.

  • Adult-onset HSP

    Less common, more severe, higher renal risk and an occasional link with underlying malignancy - specialist review is essential.

  • Red flag - intussusception

    Severe abdominal pain, blood in stool or a palpable mass needs urgent surgical review.

Treatment

How HSP is treated in the UK.

Supportive care and analgesia for most, corticosteroids for severe symptoms and specialist immunosuppression for significant kidney disease.

  • Observation and supportive care

    Most children with mild HSP recover in 4 to 6 weeks - rest, hydration and monitoring at home with clear safety-netting.

  • Simple analgesia

    Paracetamol first line. NSAIDs cautiously and avoided altogether if renal function is affected.

  • Corticosteroids

    Used selectively for severe joint pain, disabling abdominal pain, testicular involvement or nephritis - specialist rheumatology led.

  • Immunosuppression

    Cyclophosphamide or rituximab for severe or progressive nephritis - specialist commissioned paediatric nephrology only.

  • ACE inhibitor

    For persistent proteinuria - reduces urinary protein and protects the kidneys long-term.

  • Blood pressure control

    Tight hypertension control preserves kidney function - a core part of renal follow-up.

  • Renal follow-up

    Urinalysis and BP monitoring for at least 6 months - specialist paediatric nephrology if any persistent abnormality.

  • Surgical review

    Intussusception is a surgical emergency - prompt imaging and paediatric surgical input if suspected.

What this guide is based on

The sources behind every claim on this page.

UK and international guidance and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your GP or specialist knows your child's history and can tell you which parts apply to you. If in doubt, get seen.

  • EULAR/PRINTO/PRES. Classification criteria for childhood vasculitides.

  • SHARE initiative. Recommendations for the diagnosis and treatment of IgA vasculitis.

  • British Society for Paediatric and Adolescent Rheumatology (BSPAR). Vasculitis guidance.

  • NICE Clinical Knowledge Summaries. Henoch-Schönlein purpura.

  • Vasculitis UK. Patient information on IgA vasculitis.

Red flags

When HSP needs urgent attention.

Most cases are manageable at home with GP or paediatric oversight. These are the situations that aren't.

  • Severe abdominal pain

    Colicky pain with vomiting, blood in stool or a palpable mass may signal intussusception or bowel infarction - urgent surgical review.

  • Rapidly worsening rash

    Spreading purpura with skin necrosis or bullae needs urgent specialist assessment.

  • Nephritic or nephrotic syndrome

    Heavy proteinuria, oedema, hypertension or a rising creatinine needs immediate paediatric nephrology input.

  • Scrotal or testicular pain

    Orchitis can mimic testicular torsion - a same-day surgical opinion is safest.

  • Neurological symptoms

    Headache, seizures or altered consciousness are rare but can indicate cerebral involvement - emergency assessment.

  • Persistent hypertension

    Sustained raised blood pressure is a marker of renal disease and needs prompt evaluation.

  • Adult-onset disease

    Adults with HSP need specialist review - the renal risk is higher and there is a small association with malignancy.

  • Relapsing course

    Recurrent flares warrant a specialist plan and closer renal surveillance.

  • Late nephritis

    Renal disease can appear weeks after the rash settles - urinalysis at each follow-up visit matters.

Living with it

A treatable condition, with a clear follow-up.

Four things that matter through the acute weeks and the follow-up months - rest, urinalysis, warning signs and completing the 6-month plan.

A quiet reminder

The kidneys can be quiet for weeks.

A simple urine dip and blood pressure at every follow-up visit is a small step with a big pay-off.

  1. 01 Rest

    Rest during the acute phase

    Most children recover in 4 to 6 weeks. Rest, fluids and gentle activity help joint pain settle.

  2. 02 Monitor

    Watch the urine and blood pressure

    Renal involvement can develop late - urinalysis and BP checks at follow-up visits are the safety net.

  3. 03 Escalate

    Know the warning signs

    Severe abdominal pain, testicular pain, blood in urine or stool or a spreading rash means same-day review.

  4. 04 Follow-up

    Stick with the 6-month plan

    Long-term kidney risk is small but real - completing the surveillance plan is how we catch it early.

Frequently asked

Everything we get asked about HSP.

Quick answers on causes, diagnosis, steroids and kidney follow-up.

  • What is Henoch-Schönlein purpura?

    Henoch-Schönlein purpura (HSP), also called IgA vasculitis, is a small-vessel vasculitis caused by IgA immune-complex deposition. It is the most common vasculitis in children and typically causes a palpable purpuric rash on the buttocks and legs, joint pain, abdominal pain and kidney involvement.

  • What causes HSP?

    The exact cause is unknown but it often follows an upper-respiratory infection - streptococcal and viral triggers are the best recognised. It is not contagious and not inherited in a simple way.

  • How is HSP diagnosed?

    Diagnosis is clinical, using the EULAR/PRINTO/PRES criteria - palpable purpura plus at least one of joint pain, abdominal pain, renal involvement or biopsy evidence of IgA-predominant vasculitis. Urinalysis, blood pressure and basic bloods (with a normal platelet count) support the diagnosis and help rule out other causes.

  • Is HSP the same as IgA nephropathy?

    They are closely related. The kidney disease in HSP looks the same under the microscope as IgA nephropathy and is considered part of the same spectrum. HSP tends to be systemic in children, while IgA nephropathy is usually a kidney-limited disease in adults.

  • Does HSP need steroids or immunosuppression?

    Most children recover without them. Corticosteroids are used selectively for severe joint pain, disabling abdominal pain, testicular involvement or nephritis. Stronger immunosuppression, such as cyclophosphamide or rituximab, is reserved for severe or progressive kidney disease under specialist care.

  • Why does follow-up last 6 months?

    Kidney involvement can appear weeks after the rash has settled. Urinalysis and blood pressure at scheduled follow-up visits pick up late nephritis early, when treatment works best. A small proportion of patients (up to about 5%) develop long-term chronic kidney disease, so the surveillance plan is worth completing.

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