Henoch-Schönlein purpura is an immune-mediated small-vessel vasculitis that commonly causes raised red-purple spots on the legs and buttocks. The preferred modern name is immunoglobulin A vasculitis, shortened to IgA vasculitis or IgAV.
IgA-associated inflammation can affect skin, joints, the gastrointestinal tract and kidneys. Most childhood cases improve with supportive care, but a new non-blanching rash needs prompt assessment, severe abdominal symptoms can be urgent, and silent kidney involvement requires urine and blood-pressure follow-up.
How Can You Recognize the Purplish Rash of IgA Vasculitis?
The classic IgA vasculitis rash is raised, red-purple and non-blanching, a pattern called palpable purpura.
Lesions may look like small red or purple dots, larger purpuric patches or bruise-like ecchymoses. They can often be felt and do not turn pale when pressed.
The rash is commonly symmetrical, can appear in crops over several days and may have swelling beneath it. Itch is usually absent or mild.
Early lesions can resemble red spots, hives or ordinary papules before becoming clearly purpuric.
- Raised or palpable spots.
- Red, purple, grey-purple or bruise-like colour.
- Non-blanching behaviour.
- Symmetrical lower-body distribution.
- New crops over several days.
- Possible local swelling.
- Usually little or no itching.
Figure 1. IgA vasculitis commonly produces raised non-blanching purpura in symmetrical crops over the buttocks and lower limbs.
Where Does the HSP Rash Usually Appear?
The HSP rash usually appears on the buttocks, thighs, lower legs, ankles and feet.
Walking children often show the strongest pattern in pressure- and gravity-dependent areas. Arms, hands and trunk can also be involved.
Young or non-walking children may have more facial, eyelid, hand or foot swelling. Distribution supports the diagnosis but never makes a non-blanching rash safe to ignore.
| Location | How Typical? | Clinical Note |
|---|---|---|
| Buttocks | Very typical | Pressure-dependent pattern |
| Lower legs and ankles | Very typical | Common palpable purpura site |
| Feet and thighs | Common | May accompany edema |
| Arms, hands or trunk | Possible | Broader distribution |
| Face or eyelids | More likely in younger children | Swelling may be prominent |
How Can IgA Vasculitis Look Different Across Skin Tones?
IgA vasculitis may look dark red, brown-red, purple, grey-purple or bruise-like depending on skin tone and lesion age.
Individual lesions may be easier to feel than see, and new and older spots can have different colours.
Texture, symmetry, non-blanching behaviour and accompanying symptoms remain important. A glass test cannot diagnose IgA vasculitis or exclude another serious cause.
What Should You Do When a Non-Blanching Rash Appears?
A new non-blanching red or purple rash should receive urgent same-day medical assessment because several serious diseases can look similar.
- Check for fever or severe illness.
- Note confusion, neck stiffness, light sensitivity or breathing difficulty.
- Record when and where the rash began.
- Look for abdominal pain, joint swelling and urine changes.
- Check for reduced urine output or dehydration.
- Do not diagnose from an online photograph.
- Seek emergency help when serious systemic symptoms are present.
Safety route: non-blanching rash while otherwise stable → urgent review; non-blanching rash with serious illness or neurologic signs → emergency response.
How Does IgA Vasculitis Cause Purpura and Organ Symptoms?
IgA vasculitis causes purpura and organ symptoms when immune activity inflames small blood vessels and makes them leak.
IgA-containing deposits are associated with vessel-wall inflammation. Skin leakage produces palpable purpura; bowel inflammation causes pain or bleeding; joint-area inflammation causes pain and edema; kidney-filter inflammation permits blood and protein to enter urine.
The purple spots represent blood beneath the skin rather than ordinary traumatic bruising.
Figure 2. IgA-associated small-vessel inflammation can affect skin, joints, bowel and kidney filtering units.
What Causes Henoch-Schönlein Purpura?
The exact cause of IgA vasculitis remains unknown.
It reflects an abnormal immune response rather than direct infection of the rash. Respiratory infections, viruses, bacteria, group A streptococcus, selected medicines, immunisations, insect bites, foods in isolated reports and genetic susceptibility have been associated with onset.
A preceding exposure does not prove individual causation. IgA vasculitis is not caused by poor hygiene and is not contagious.
| Preceding Factor | Possible Link | Universal Cause? |
|---|---|---|
| Respiratory infection | Common preceding context | No |
| Group A streptococcus | Reported trigger | No |
| Medicine | Possible immune trigger | No |
| Immunisation | Reported in some cases | No |
| Insect bite or food | Case-level association | No |
| Poor hygiene or touch | No causal role | No |
Who Is More Likely to Develop IgA Vasculitis?
IgA vasculitis occurs most often in children, commonly between about two and eight years, with peak frequency around four to seven years.
Adolescents and adults can also develop the disease. Family susceptibility and a recent respiratory infection may be present.
Adults require particular kidney caution because persistent renal disease is more common than in children.
| Age or Context | Usual Pattern | Caution |
|---|---|---|
| Young child | Common presentation | Kidney monitoring remains essential |
| Adolescent | Broader differential | Exclude alternatives |
| Adult | Less common | Greater persistent renal concern |
| Family history | Susceptibility may increase | Not deterministic |
Which Four Body Systems Are Commonly Affected by IgA Vasculitis?
IgA vasculitis commonly affects skin, joints, the gastrointestinal tract and kidneys.
| System | Common Finding | Major Concern | Monitoring |
|---|---|---|---|
| Skin | Palpable purpura | Bullous or necrotic lesions | Rash evolution |
| Joints | Pain and swelling | Alternative cause if one hot joint | Function and exam |
| GI tract | Pain, vomiting or bleeding | Intussusception or ischemia | Abdominal warning signs |
| Kidneys | Hematuria, proteinuria or high BP | Chronic kidney disease | Urine and blood pressure |
Symptoms can appear in any order. Kidney involvement can become detectable after skin and joint symptoms improve.
How Does IgA Vasculitis Affect the Joints?
IgA vasculitis commonly causes temporary pain and swelling around the ankles and knees.
Hands and feet can become edematous, and walking may be painful. Large lower-limb joints are affected more often than small joints.
A hot single joint, large effusion, persistent focal pain or inability to walk needs assessment for infection, injury or another arthritis.
| Site | Typical Finding | Alternative Warning |
|---|---|---|
| Ankles | Pain and swelling | Severe inability to walk |
| Knees | Pain, sometimes swelling | Hot single joint |
| Hands or feet | Soft-tissue edema | Persistent focal pain |
| One joint | Less typical if very hot | Septic arthritis or injury |
How Can IgA Vasculitis Affect the Stomach and Intestines?
IgA vasculitis can cause abdominal pain when inflamed intestinal vessels produce bowel-wall swelling or bleeding.
Symptoms include cramping or diffuse pain, nausea, vomiting, reduced appetite, tenderness and visible or occult blood in stool.
Abdominal symptoms can begin before the skin rash and may fluctuate.
GI pathway: vessel inflammation → bowel-wall swelling → pain and vomiting → bleeding or obstruction risk.
Which Abdominal Complications Require Emergency Care?
Severe or rapidly worsening abdominal pain can signal bowel obstruction or tissue injury.
- Severe or repeated waves of pain.
- Persistent vomiting.
- Green or bilious vomit.
- Swollen abdomen.
- Significant blood in stool.
- Guarding or rigid abdomen.
- Marked lethargy.
- Inability to drink.
- Dehydration signs.
Possible complications include intussusception, gastrointestinal hemorrhage, bowel ischemia, necrosis, perforation, pancreatitis and protein-losing enteropathy.
Severe symptoms may require urgent ultrasound and surgical review.
How Does IgA Vasculitis Affect the Kidneys?
IgA vasculitis can affect the kidneys by causing blood or protein in urine, high blood pressure or reduced filtration.
Findings include microscopic hematuria, visible red or tea-coloured urine, proteinuria, swelling, hypertension, nephritic or nephrotic syndrome and acute kidney injury.
Kidney involvement may initially cause no visible symptom. Normal-looking urine and absence of swelling do not exclude it.
| Finding | Possible Meaning | Action |
|---|---|---|
| Microscopic blood | Renal involvement | Follow-up testing |
| Visible blood | Active renal disease | Prompt review |
| Proteinuria | Glomerular injury | Quantify protein loss |
| High blood pressure | Renal hypertension | Medical review |
| Reduced eGFR | Reduced filtration | Nephrology assessment |
Why Must Urine and Blood Pressure Be Monitored After the Rash Improves?
Urine and blood pressure must be monitored after the rash improves because kidney abnormalities can appear later and may remain silent.
Urinalysis detects blood and protein, blood-pressure measurement detects hypertension, and a first-morning urine protein-to-creatinine ratio quantifies ongoing protein loss.
Current paediatric nephrology recommendations support at least monthly assessment during the first six months even when initial urine testing is normal.
Patients who develop clinical nephritis need close follow-up for at least five years, with longer surveillance for severe or active disease.
Monitoring timeline: diagnosis → monthly urine and BP checks during the first six months → extended follow-up after nephritis.
Can IgA Vasculitis Cause Swelling Without Kidney Disease?
IgA vasculitis can cause local painful swelling from skin and soft-tissue inflammation even when kidney tests are normal.
Hands, feet, eyelids and scrotal skin may swell, particularly in younger children.
HSP edema is usually inflammatory, while sudden facial, lip, eyelid or throat swelling may suggest angioedema or another urgent diagnosis.
Generalized swelling, persistent facial puffiness or rapid weight gain raises greater concern for protein loss or kidney dysfunction.
| Swelling Pattern | Likely Direction | Needed Check |
|---|---|---|
| Local hand or foot edema | Inflammatory soft tissue | Clinical and renal assessment |
| Periorbital swelling | Can be inflammatory | Urine and BP still required |
| Generalized edema | Possible protein loss | Urine protein and kidney tests |
| Sudden throat or facial swelling | Possible allergic airway process | Urgent assessment |
How Can IgA Vasculitis Affect the Testicles or Scrotum?
IgA vasculitis can cause scrotal swelling, bruising, orchitis or testicular pain.
Spermatic-cord inflammation or hematoma can occur, but sudden severe one-sided testicular pain must be treated as possible torsion.
Scrotal route: mild swelling with known IgAV → urgent clinical review; acute severe unilateral pain → emergency torsion assessment.
Which Uncommon Organs Can IgA Vasculitis Affect?
IgA vasculitis rarely affects organs outside the skin, joints, bowel and kidneys, but neurologic or respiratory involvement is serious.
| Organ | Warning Sign | Urgency |
|---|---|---|
| Brain or CNS | Seizure, confusion or focal weakness | Emergency |
| Lungs | Breathing difficulty or pulmonary bleeding | Emergency |
| Pancreas | Severe abdominal pain and vomiting | Urgent |
| Gallbladder or other GI organs | Severe persistent abdominal symptoms | Urgent |
How Does IgA Vasculitis Differ in Adults and Children?
IgA vasculitis is more common in children, but adults may have more severe skin, gastrointestinal or kidney involvement.
| Feature | Childhood IgAV | Adult IgAV |
|---|---|---|
| Frequency | More common | Less common |
| Course | Often self-limited | More renal caution |
| Persistent kidney risk | Generally lower | Higher |
| Follow-up | Required | Often longer and specialist-led |
Adult cases should not rely on casual childhood reassurance or stop follow-up when the rash fades.
How Is IgA Vasculitis Different From Meningococcal Disease?
IgA vasculitis and meningococcal disease can both produce non-blanching purpura, but meningococcal infection can cause rapid severe illness.
IgA vasculitis often concentrates on the legs and buttocks and may occur with joint or abdominal symptoms over days.
Fever, rapid deterioration, neck stiffness, light sensitivity, altered consciousness or quickly spreading purpura requires emergency treatment.
| Feature | IgA Vasculitis | Meningococcal Emergency |
|---|---|---|
| General condition | May appear relatively well | Often severely unwell |
| Rash | Lower-body concentration common | Can spread rapidly |
| Associated signs | Joint, bowel or kidney symptoms | Fever and systemic toxicity |
| Neurologic clues | Rare | Neck stiffness or confusion |
| Action | Urgent assessment | Immediate emergency care |
How Is IgA Vasculitis Different From a Low-Platelet Purpura?
IgA vasculitis usually causes palpable purpura with a normal platelet count, while thrombocytopenic purpura often causes flatter petechiae or bruises with reduced platelets.
| Feature | IgA Vasculitis | Low-Platelet Purpura |
|---|---|---|
| Texture | Usually palpable | Often flat |
| Platelet count | Usually normal | Reduced |
| Distribution | Legs and buttocks common | Can be generalized |
| Bleeding pattern | Purpura with GI or renal findings | Nose or gum bleeding may occur |
| Key tests | Urine, BP and CBC | CBC and platelets |
Which Other Conditions Can Resemble HSP Purpura?
Dangerous infections, blood disorders, other vasculitides and medication-related disease can resemble IgA vasculitis.
A medication history matters because a drug rash or drug-induced small-vessel vasculitis can produce purpuric change in selected cases.
General viral exanthems can cause widespread red rashes, but they usually do not create the same palpable non-blanching pattern with kidney-monitoring requirements.
| Condition | Defining Clue | Urgent Test | Different Pathway |
|---|---|---|---|
| Meningococcal disease or sepsis | Very unwell, fever, rapid spread | Emergency assessment and cultures | Immediate antibiotics |
| Immune thrombocytopenia | Low platelets and bleeding | CBC and platelets | Hematology |
| Leukemia | Bruising, fatigue or abnormal CBC | CBC and smear | Hematology or oncology |
| Drug-induced vasculitis | Medication timing | History, labs and possible biopsy | Culprit review |
| ANCA vasculitis | Renal or lung signs | ANCA, renal tests and biopsy | Specialist immunosuppression |
| SLE | Multisystem autoimmune signs | ANA, complement and renal tests | Rheumatology |
| HUS | Hemolysis, renal injury, low platelets | CBC and renal tests | Urgent renal care |
| Septic emboli | Infection source | Blood cultures and imaging | Hospital infection care |
How Do Clinicians Diagnose IgA Vasculitis?
Clinicians diagnose IgA vasculitis by combining the purpura pattern with organ assessment and tests that check kidneys and exclude dangerous alternatives.
- Medical history and recent exposures.
- Rash distribution, palpability and evolution.
- Joint and abdominal assessment.
- Blood-pressure measurement.
- Urinalysis for blood and protein.
- Assessment for edema.
- Kidney-function testing when indicated.
- Exclusion of thrombocytopenia, infection and other vasculitides.
There is no single diagnostic blood test. A typical childhood presentation is often diagnosed clinically, but renal involvement must still be assessed.
Which Tests Are Used When HSP Is Suspected?
The core tests for suspected HSP are urinalysis and blood-pressure measurement.
| Test | Question Answered | Management Change |
|---|---|---|
| Urinalysis | Blood or protein present? | Renal follow-up |
| Blood pressure | Hypertension present? | Kidney evaluation |
| First-morning UPCR | How much protein is lost? | Nephrology threshold |
| Creatinine and eGFR | Is filtration reduced? | Urgent renal care |
| CBC and platelets | Low platelets or leukemia? | Alternative diagnosis |
| Cultures | Could infection be present? | Antibiotic pathway |
| Abdominal ultrasound | Could intussusception be present? | Surgical or emergency care |
Urine microscopy, electrolytes, albumin, inflammatory markers, complement, autoimmune tests and cultures are selected according to findings.
When Is a Skin Biopsy Needed for IgA Vasculitis?
A typical childhood IgA vasculitis rash usually does not need skin biopsy, but atypical purpura may require a fresh-lesion biopsy.
- Unusual distribution.
- Extensive, ulcerative or atypical lesions.
- Uncertain diagnosis.
- Older child or adult with possible systemic vasculitis.
- Concern for ANCA-associated vasculitis.
- Blood count or systemic findings that do not fit.
Histology may show leukocytoclastic small-vessel vasculitis, while direct immunofluorescence can show IgA deposition. Findings must be interpreted with the clinical pattern.
When Is a Kidney Biopsy Needed?
Kidney biopsy may be needed when IgA vasculitis causes severe, persistent or rapidly worsening renal findings that could change treatment.
| Kidney Finding | Severity or Duration | Biopsy Direction |
|---|---|---|
| Nephrotic-range proteinuria | Significant | Strong consideration |
| Reduced eGFR | Any concerning reduction | Strong consideration |
| Persistent moderate proteinuria | Ongoing | Specialist decision |
| Mild proteinuria | Persistent despite follow-up | Escalate by trend |
| Rapid progression | Declining filtration | Urgent nephrology |
| Nephritic or nephrotic syndrome | Clinically significant | Biopsy-guided treatment |
Kidney histology assesses active inflammation, crescent formation and chronic scarring.
Does Mild IgA Vasculitis Require Specific Treatment?
Most uncomplicated childhood IgA vasculitis improves without disease-specific treatment, but kidney monitoring remains required.
Rest can help painful joint or swelling episodes, fluids support recovery when vomiting is absent, and pain relief must fit kidney and gastrointestinal status.
The purpuric rash itself usually does not need topical medication. Self-limited disease does not mean follow-up can stop.
| Situation | Best Direction | Reason |
|---|---|---|
| Mild symptoms and normal renal assessment | Supportive care plus monitoring | Often self-limited |
| Joint pain | Rest and safe analgesia | Comfort and function |
| No vomiting | Fluids as tolerated | Hydration |
| Rash alone | Usually no topical treatment | Vascular leakage |
| Organ complication | Targeted treatment | Higher risk |
| Rash resolved | Continue urine and BP checks | Delayed nephritis possible |
Which Pain Medicines Can Be Used Safely During HSP?
Pain medicine during HSP should be chosen according to kidney function, hydration and gastrointestinal bleeding risk.
Paracetamol or acetaminophen is commonly used. An NSAID may sometimes be considered for joint pain when renal function is normal and gastrointestinal bleeding is absent.
NSAIDs should be avoided or used only after clinical guidance when kidney involvement, dehydration, severe abdominal disease or gastrointestinal bleeding is possible. Aspirin is not routine kidney-prevention therapy.
| Situation | Safer Direction | Avoid or Review |
|---|---|---|
| Mild pain | Paracetamol or acetaminophen | NSAID without advice |
| Normal renal/GI status | Clinician-guided NSAID may be possible | Self-directed NSAID |
| Kidney involvement | Specialist-guided analgesia | NSAIDs |
| GI bleeding or severe pain | Medical review | NSAIDs |
| Dehydration or vomiting | Medical review | NSAIDs |
When Are Glucocorticoids Used for IgA Vasculitis?
Glucocorticoids may be used for selected severe symptoms, but they should not be given automatically to prevent kidney disease.
They may shorten moderate or severe abdominal pain, severe joint symptoms, orchitis or significant soft-tissue swelling. Intussusception must be excluded when abdominal pain is severe.
Steroids do not reliably prevent nephritis. Dose and tapering require clinician supervision.
| Steroid Use | Possible Role | Not Supported For |
|---|---|---|
| Severe abdominal pain | Symptom relief | Automatic use in all cases |
| Severe joint symptoms | Symptom relief | Nephritis prevention |
| Orchitis or soft-tissue swelling | Selected use | Mild rash only |
| Severe nephritis | Biopsy-guided therapy | Rash appearance alone |
How Is IgA Vasculitis Nephritis Treated?
IgA vasculitis nephritis is treated according to proteinuria, blood pressure, kidney function and biopsy findings when needed.
Treatment aims to reduce protein loss, control blood pressure, preserve filtration and suppress severe active inflammation.
An ACE inhibitor or angiotensin receptor blocker may be used for persistent proteinuria. Glucocorticoids and other immunosuppressive medicines are reserved for selected severe or biopsy-guided disease.
Paediatric nephrology or adult renal specialists individualise treatment and toxicity monitoring.
Which HSP Treatment Mistakes Should Be Avoided?
HSP treatment mistakes often occur when the visible rash is treated as the entire disease and renal, bowel or emergency findings are missed.
| Mistake | Why Dangerous | Safer Response |
|---|---|---|
| Assuming purpura is harmless HSP | Missed sepsis or another disease | Urgent assessment |
| Stopping follow-up after skin clears | Delayed nephritis missed | Continue urine and BP |
| Bleaching or antifungal creams | Wrong target | Medical assessment |
| NSAIDs with renal or GI risk | Kidney or bleeding harm | Clinician-guided analgesia |
| Steroids only to prevent nephritis | Unsupported use | Selected indications only |
| Delaying severe-pain ultrasound | Missed intussusception | Urgent imaging |
| Assuming scrotal pain is HSP | Missed torsion | Emergency examination |
| Ignoring high blood pressure | Renal damage | Prompt kidney review |
| Treating recurrence without urine tests | Delayed renal disease | Repeat urine and BP |
How Long Does IgA Vasculitis Last?
Skin, joint and abdominal symptoms may improve within several weeks, but kidney monitoring can continue long after the rash fades.
Some cases continue for months, and new crops of purpura may appear during recovery. Kidney abnormalities can outlast visible skin findings.
Severe nephritis may require years of follow-up. Skin recovery and kidney recovery are not interchangeable outcomes.
Can Henoch-Schönlein Purpura Return?
Henoch-Schönlein purpura can return one or more times, often during the first year after the original episode.
The rash may recur with or without abdominal and joint symptoms. Kidney tests and blood pressure must be repeated during each flare.
A recurrent non-blanching rash still needs assessment because another disease can mimic the previous diagnosis.
Relapse route: new purpura → clinical reassessment → urine and BP testing → organ review → renewed monitoring.
What Long-Term Complications Can IgA Vasculitis Cause?
Chronic kidney disease is the most important long-term complication of IgA vasculitis.
Persistent proteinuria, hypertension, reduced filtration and rare kidney failure can follow severe nephritis. Severe bowel disease can cause lasting intestinal injury or require surgery.
Uncommon severe disease can produce bullous or necrotic lesions, so rapidly spreading blisters or skin breakdown need urgent assessment rather than routine rash care.
Adults have a greater likelihood of persistent renal damage, and a previous history can affect pregnancy monitoring.
How Does a History of IgA Vasculitis Affect Pregnancy?
A previous history of IgA vasculitis should be shared with the maternity team because blood pressure and urine protein may need closer monitoring.
Previous renal involvement increases the value of kidney review. Pregnancy medication plans may require adjustment, particularly with ACE inhibitors or ARBs.
A remote childhood episode without documented renal follow-up should still be mentioned.
Can IgA Vasculitis Be Prevented?
There is no established way to prevent every case of IgA vasculitis.
Treating an ordinary respiratory infection does not guarantee prevention, and routine glucocorticoids do not prevent nephritis.
Aspirin, heparin, dipyridamole, montelukast, elimination diets, supplements and immune detoxes should not be used solely to prevent renal involvement without another indication.
Early recognition cannot stop disease onset but can reduce delayed detection of kidney and gastrointestinal complications.
When Is IgA Vasculitis a Medical Emergency?
IgA vasculitis requires emergency care when a non-blanching rash occurs with serious systemic, abdominal, renal, neurologic, respiratory or dehydration signs.
- Fever or severe illness.
- Confusion, neck stiffness or light sensitivity.
- Difficulty breathing.
- Severe or worsening abdominal pain.
- Persistent or green vomiting.
- Significant blood in stool.
- Swollen or rigid abdomen.
- Sudden severe testicular pain.
- Seizure or focal weakness.
- Visible blood in urine.
- Markedly reduced urine output.
- New generalized swelling.
- Severe headache with high blood pressure.
- Rapidly spreading blistering or necrotic skin.
- Inability to drink or dehydration signs.
Spreading warmth, increasing pain, fever, pus or rapidly worsening redness should also raise concern for infection patterns such as cellulitis, not only IgA vasculitis.
Figure 3. A new non-blanching rash needs urgent assessment, every suspected case needs urine and blood-pressure checks, and severe organ findings require escalation.
What Should You Remember About Henoch-Schönlein Purpura?
Henoch-Schönlein purpura is now preferably called IgA vasculitis.
- It inflames small blood vessels in skin and sometimes joints, intestines and kidneys.
- Its hallmark rash is raised, red-purple and non-blanching.
- The buttocks and lower limbs are commonly affected.
- Symptoms can appear in different orders.
- Most childhood cases improve with supportive care.
- Every new non-blanching rash needs prompt assessment.
- Severe abdominal pain can indicate intussusception or bowel injury.
- Kidney involvement may initially be silent.
- Every suspected case needs urine and blood-pressure assessment.
- Glucocorticoids may relieve selected severe symptoms but do not prevent nephritis.
- Persistent proteinuria or reduced filtration needs nephrology assessment.
- Follow-up continues after the rash resolves.
What Questions Do People Ask About Henoch-Schönlein Purpura?
Is Henoch-Schönlein purpura the same as IgA vasculitis?
Yes. Henoch-Schönlein purpura is now preferably called IgA vasculitis because immunoglobulin A is associated with inflammation in small blood vessels.
What does the HSP rash look like?
It usually appears as raised red, purple, grey-purple or bruise-like non-blanching spots, often on the buttocks, legs, ankles or feet.
Does an HSP rash disappear when pressed?
No. Classic purpura does not blanch because blood has leaked beneath the skin. A glass test cannot diagnose IgA vasculitis or exclude an emergency.
Is IgA vasculitis contagious?
No. It is an immune-mediated vasculitis and cannot spread through touching the spots, shared clothing or ordinary contact.
Can HSP begin before the purple rash appears?
Yes. Abdominal pain, joint pain, swelling or other symptoms may begin before the rash becomes clearly purpuric.
Why does HSP usually affect the legs and buttocks?
The rash commonly appears in pressure- and gravity-dependent areas, especially the buttocks and lower limbs of walking children.
Can IgA vasculitis cause severe stomach pain?
Yes. Bowel-vessel inflammation can cause cramping, vomiting or bleeding. Severe or worsening pain, green vomit, blood in stool, swelling or dehydration needs urgent care.
How does HSP affect the kidneys?
It can cause blood or protein in urine, high blood pressure and reduced filtration. Kidney involvement may be silent initially.
Can kidney disease develop after the rash clears?
Yes. Kidney abnormalities may appear after skin, joint or abdominal symptoms improve, so urine and blood-pressure follow-up must continue.
How often should urine and blood pressure be checked?
Follow the treating clinician’s plan. Current paediatric nephrology recommendations support at least monthly assessment during the first six months even when initial urinalysis is normal, with much longer follow-up after nephritis.
Can children take ibuprofen during HSP?
Ibuprofen and other NSAIDs should not be used without medical advice because kidney involvement, dehydration or gastrointestinal bleeding can make them unsafe.
Do steroids prevent HSP kidney complications?
No. Glucocorticoids may relieve selected severe abdominal, joint or soft-tissue symptoms but do not reliably prevent nephritis.
When does IgA vasculitis require a skin biopsy?
A typical childhood presentation usually does not require one. Biopsy may help with atypical distribution, extensive, ulcerative or unusual lesions, adult disease, uncertain diagnosis or concern for another vasculitis.
When is a kidney biopsy needed?
Biopsy may be needed for nephrotic-range proteinuria, reduced filtration, persistent proteinuria, rapidly progressive dysfunction, nephritic or nephrotic syndrome, or findings that would change immunosuppressive treatment.
Can Henoch-Schönlein purpura return?
Yes. Symptoms can recur, often during the first year. Each flare needs reassessment and repeat urine and blood-pressure testing.
Is IgA vasculitis more serious in adults?
Adult IgA vasculitis is less common but carries greater concern for persistent kidney disease, so careful renal assessment and follow-up are needed.
When does a purplish non-blanching rash require emergency care?
Emergency care is needed with severe illness, fever, confusion, neck stiffness, breathing difficulty, severe abdominal pain, persistent or green vomiting, significant stool or urine blood, reduced urine, seizure, focal weakness, severe hypertension symptoms, dehydration, or rapidly spreading blistering or necrotic lesions.
Which Sources Support This IgA Vasculitis Guidance?
NIDDK — IgA Vasculitis — Terminology, mechanism, organ symptoms, adult renal risk, recurrence and pregnancy monitoring.
NHS — Henoch-Schönlein Purpura — Urgent non-blanching-rash assessment, emergency illness signs and treatment safety.
Royal Children’s Hospital — HSP Guideline — Urinalysis and blood-pressure requirements, complications, tests, NSAID caution, steroids and follow-up.
IPNA — IgA Vasculitis Nephritis Recommendations — First-morning protein measurement, monitoring, biopsy thresholds and renal treatment.
This SkinKeeps article is educational and does not diagnose or replace paediatric, primary, dermatology, nephrology, gastrointestinal, infectious-disease, haematology, surgical, emergency or maternity care. A new non-blanching rash needs prompt assessment. Seek urgent care for severe illness, breathing difficulty, neurologic symptoms, severe abdominal pain, green vomiting, blood in stool or urine, reduced urine, dehydration, testicular pain, widespread swelling, infection signs or rapidly spreading blistering or necrotic skin. Do not self-diagnose, stop kidney follow-up, use unsafe NSAIDs or start steroids solely to prevent nephritis.
