Synopsis
Recognise IgA vasculitis clinically, detect delayed renal involvement through systematic urine and blood-pressure surveillance, manage gastrointestinal and renal red flags, and refer proteinuria, hypertension or impaired function promptly.
- IgA vasculitis is an IgA-mediated small-vessel vasculitis, formerly called Henoch–Schönlein purpura, most common in children under 10 years.
- The diagnostic pattern is palpable non-thrombocytopenic purpura, usually on buttocks and lower limbs, plus one or more of abdominal pain, arthritis or arthralgia, renal involvement or IgA-predominant histology.
- Renal involvement may be silent and delayed. It ranges from microscopic haematuria to proteinuria, hypertension, nephritic or nephrotic syndrome and rapidly progressive kidney injury.
- First-line assessment includes blood pressure plotted for age, sex and height, urinalysis for blood and protein, and urine protein:creatinine or albumin:creatinine ratio when either is positive.
- Check FBC when diagnosis is uncertain to demonstrate a normal platelet count, and renal profile and albumin when urine, blood pressure or systemic severity is abnormal.
- A normal first urinalysis does not end surveillance. The NHSGGC pathway checks blood pressure and urine at 1 week, 1 month, 3 months, 6 months and 12 months when results remain normal.
- An alternative widely used NHS schedule is weekly urine and blood pressure for 6 weeks then monthly to 6 months; follow the local pathway consistently and extend review whenever abnormalities occur.
- Isolated microscopic haematuria usually needs continued surveillance rather than immunosuppression. Proteinuria magnitude, hypertension and eGFR determine renal urgency.
- First-line management for uncomplicated skin and joint disease is hydration, rest as needed and paracetamol. Avoid NSAIDs when renal involvement, bleeding, dehydration or abdominal complications are possible.
- Corticosteroids may reduce severe abdominal or joint symptoms but do not reliably prevent later nephritis; do not prescribe them solely to protect normal kidneys.
- Persistent or increasing proteinuria, nephrotic syndrome, hypertension or reduced function requires paediatric nephrology, possible biopsy and disease-specific renin–angiotensin blockade or immunosuppression.
- Most children recover fully, but renal prognosis is determined by kidney involvement rather than rash severity; maintain surveillance even after purpura and pain resolve.
Key red flags
Severe colicky abdominal pain, bilious vomiting, bloody stool, abdominal mass or lethargy suggests intussusception or bowel ischaemia.
Hypertension, reduced urine output, oedema, macroscopic haematuria or rising creatinine indicates significant IgA vasculitis nephritis.
Nephrotic-range proteinuria, serum albumin below 30 g/L or rapidly increasing proteinuria requires urgent nephrology assessment.
eGFR below 60 mL/min/1.73 m², rapidly deteriorating function or hypertensive neurological symptoms requires admission and immediate specialist management.
Purpura with thrombocytopenia, coagulopathy, shock or meningism is not a typical uncomplicated IgA vasculitis phenotype and requires an alternative emergency pathway.
Pulmonary haemorrhage, seizure, confusion or focal neurological change is rare but requires intensive multidisciplinary care.
Investigation priorities
Detect clinically silent renal involvement at diagnosis and throughout follow-up.
Management branches
Palpable dependent purpura suggests possible IgA vasculitis.
- Assess sepsis, abdominal emergency and neurological red flags before accepting a benign vasculitis course.
- Measure blood pressure, urinalysis and height; quantify protein and check renal function when abnormal.
- Provide symptom care and a written renal-surveillance schedule even when initial urine and pressure are normal.