Henoch-Schönlein Purpura (IgA Vasculitis)

Table of contents
Key points ⚡
Succinct notes to superpower your revision
Henoch-Schönlein purpura (HSP)\: IgA vasculitis presenting with glomerulonephritis, abdominal pain, arthralgia, and
purpura; most common vasculitis in children, incidence 20 per 100,000.
Aetiology\: immune-mediated small vessel vasculitis with IgA and complement deposits in vessel walls; often follows an
upper respiratory tract infection (URTI).
Risk factors\: preceding URTI, age 4-6 years, male sex (male-to-female ratio 1.5\:1).
Symptoms\: purpuric/petechial rash on lower limbs/buttocks, abdominal pain, joint pain (arthralgia), frothy urine
(proteinuria), haematuria, low-grade fever.
History\: assess for preceding URTI (7-14 days prior), rash distribution, abdominal symptoms, and renal involvement.
Examination\: petechiae (\<3mm) and purpura (>3mm, palpable) on lower limbs/buttocks, arthralgia (swelling/tenderness of
hips, knees, ankles), GI symptoms (pain, nausea, vomiting), renal signs (haematuria, proteinuria).
Di
syndrome (HUS), mechanical causes (e.g., forceful coughing/vomiting), non-accidental injury.
Investigations\: blood pressure (renal involvement), urinalysis (proteinuria, haematuria), U&Es (renal function), FBC, clotting
studies, LFTs, urine microscopy, anti-streptolysin O titre (rare), abdominal ultrasound (exclude intussusception), renal biopsy
(if severe).
Diagnosis\: Paediatric Rheumatology European Society criteria (palpable purpura + one of\: abdominal pain, arthralgia, renal
involvement, typical histopathology).
Management\: supportive care (paracetamol for pain, prednisolone for severe pain, cautious use of NSAIDs), regular follow-
up for renal involvement (urine dip, blood pressure for six months).
Complications\: relapse (30-40%), renal failure (1% leading to end-stage renal failure).
Article 🔍
A comprehensive topic overview

Introduction

Henoch-Schönlein purpura (HSP) is an IgA vasculitis which commonly presents with glomerulonephritis, abdominal pain,
arthralgia and purpura.
It is the most common vasculitis in children, with an annual incidence of 20 per 100,000 in children under 17.
1

Aetiology

HSP is an immune-mediated small vessel vasculitis. IgA and complement components (C3) are deposited in vessel walls
leading to in
The mechanism underlying this is not entirely clear, but HSP can follow an upper respiratory tract infection, so it is
thought to be triggered by an abnormal immune system response.
2Risk factors
The most notable risk factor for HSP is a preceding upper respiratory tract infection.
Other risk factors include\:
1
Age\: the incidence of HSP peaks in those aged 4-6 years old
Male sex\: HSP is more common in boys, with a male-to-female ratio of approximately 1.5\:1

Clinical features

History
Typical symptoms of HSP include\:
Purpuric and petechial rash\: most commonly on the lower limbs and buttock
Abdominal pain\: commonly associated with nausea and vomiting and less commonly bloody diarrhoea may be seen.
Joint pain\: arthralgia occurs in the knees and ankles and may be associated with peri-articular oedema.
Frothy urine\: suggestive of proteinuria due to renal involvement
Haematuria\: due to renal involvement
Fever\: low-grade fever may be present
Other important areas to cover in the history include\:
Preceding upper respiratory tract infection\: URTI symptoms may occur 7-14 days before the presentation of HSP
symptoms
Clinical examination
Rash
1,2,5
Petechia and purpura most commonly a
this is not always the case, and it can occur on the upper limbs in up to one-third of cases.
Petechiae vs purpura4
Petechiae are non-blanching pinpoint spots \<3mm in diameter
Purpura are non-blanching spots >3mm in diameter and are commonly palpable
Figure 1. Purpuric petechial rash of HSP
Joints
Arthralgia occurs in about 80% of HSP cases and can occur in any joint, but the hips, knees, and ankles are most
commonly a
Along with arthralgia, swelling and tenderness can occur, but erythema is less likely.
Joint involvement in HSP is transient and doesn’t persist after the acute illness with no long-term damage to the joint.
1,2,5
Abdomen
Gastrointestinal symptoms occur in 50% of cases and tend to present around seven days after the onset of the rash.The presentation ranges from mild symptoms such as abdominal pain, nausea and vomiting to severe presentations
including gastrointestinal haemorrhage and intussusception.
1,3,5
Renal
Approximately 50% of HSP patients develop renal involvement, which is on a wide clinical spectrum\:
2
Microscopic or macroscopic haematuria
Proteinuria
Nephrotic syndrome\: proteinuria, oedema and hypoalbuminemia
Nephritic syndrome\: oedema, haematuria and hypertension
Renal failure

Di

It is important to consider a wide range of di
children with a non-blanching rash require a same-day paediatric assessment.
3.4
For more information, see the Geeky Medics guide to non-blanching rashes.
Meningococcal septicaemia
Meningococcal septicaemia is an important di
The child will be systemically unwell with a high-grade fever and signs of shock (hypotension and tachycardia). In
contrast, the child is likely to be clinically stable in HSP.
On examination, reduced consciousness, photophobia and neck sti
Idiopathic thrombocytopenic purpura (ITP)
ITP is a fall in the patient’s platelet count (thrombocytopenia), causing a purpuric rash. It is commonly triggered by a viral
infection. Children with ITP are generally well but can present with bleeding (e.g. epistaxis).
Haemolytic uraemic syndrome (HUS)
HUS is a triad of thrombocytopenia, acute kidney injury (AKI) and microangiopathic haemolytic anaemia caused by an E .
c o l i infection.
Like HSP, these children present with abdominal pain and a petechial rash. However, the key distinguishing feature of HUS
is the presence of bloody diarrhoea.
Mechanical causes
Forceful coughing and vomiting can cause a petechial rash in the distribution of the superior vena cava. A rash is seen on
the head, neck and shoulder rather than the lower limbs like HSP.
It is always important to consider non-accidental injury as a cause of a petechial rash in a paediatric setting.

Investigations

Bedside investigations
Relevant bedside investigations include\:
5
Blood pressure\: if elevated, this suggests renal involvement.
Urinalysis\: proteinuria or haematuria indicate renal involvement. It is important to note that an early morning urine
sample is the most reliable and should be used for a protein\: creatinine ratio.
Laboratory investigations
Relevant laboratory investigations include\:
1,5
U&E\: to assess renal functionFull blood count and clotting studies\: likely to be normal in the context of HSP but required to exclude other causes of
a non-blanching rash (e.g. ITP)
Liver function tests\: including albumin to assess for hypoalbuminemia, which is suggestive of nephrotic syndrome
Urine microscopy\: assesses for red cell casts
Anti-streptolysin O titre\: can be performed to look for g r o u p A s t r e p t o c o c c a l antibodies but is rarely performed in
clinical practice.
Imaging
Relevant imaging investigations include\:
5
Abdominal ultrasound\: may be performed to exclude intussusception as a complication in the context of severe
abdominal pain.
Other investigations
Other relevant investigations include\:
5
Renal biopsy\: only performed if there is signi
guidance.

Diagnosis

The Paediatric Rheumatology European Society has produced a set of diagnostic criteria which state that palpable
purpura and one of the following should be present for diagnosis\:
7
Di
Arthralgia
Renal involvement
Typical histopathology (glomerulonephritis or vasculitis)

Management

Most children with HSP have a complete spontaneous recovery within weeks to months but may require supportive care\:
6
Paracetamol can be used for joint and abdominal pain
Prednisolone may be considered for severe pain, but it is important to note that there is no evidence that steroids
improve overall outcomes
NSAIDs (e.g. such as ibuprofen) should be used cautiously in those with renal involvement
Follow up6
Children with HSP must be followed up closely as renal involvement may not manifest until weeks later.
Speci
blood pressure reading regularly for six months after diagnosis.
Children with concerning features for renal involvement (e.g. proteinuria >2+
, frank haematuria or hypertension) must be re-
reviewed in secondary care.
Children can then be fully discharged if they have two consecutive normal urine dips and a normal blood pressure at six
months.

Complications

Complications of Henoch-Schönlein purpura include\:
1,2,6
Relapse\: relapse rates are 30 - 40%, but relapses tend to be shorter and less severe than the original presentation.
Renal failure\: approximately 1% of HSP cases result in end-stage renal failure, this is more likely in children who initially
present with nephrotic and nephritic syndromeReferences
Up to Date\: IgA vasculitis (Henoch-Schönlein purpura)\: Clinical manifestations and diagnosis. Published in 2023. Available
from\: [LINK]
National Library of Medicine\: Henoch Schönlein Purpura. Published in 2022. Available from\: [LINK]
Dr Bethany Mitchell. Non-blanching Rashes. Published 2021. Available from\: [LINK]
Kingston Hospital NHS Foundation Trust\: Non-blanching rashes in children. Published 2023. Available from\: [LINK]
BMJ Best Practice. IgA vasculitis (Henoch-Schonlein purpura). Published 2021. Available from\: [LINK]
Cymru NHS. Guidelines for the management of Henoch Schonlein purpura. Published 2011. Available from\: [LINK]
Patient.info. Henoch-Schönlein purpura. Published 2019. Available from\: [LINK]
Image references
Figure 1. Madhero88. H e n o c h-S c h o n l e i n p u r p u r a . License\: [CC-BY-SA]. Available from\: [
LINK
]

Reviewer

Dr Alex Brightwell
Consultant Paediatrician

Related notes

Acute Kidney Injury (AKI)
Chronic Kidney Disease (CKD)
Glomerular Disease (Glomerulonephropathies)
Haemodialysis
Hyperkalaemia

Test yourself

Contents

Introduction
Aetiology
Risk factors
Clinical features
Di
InvestigationsSource\: geekymedics.com