What is the treatment for Henoch-Schönlein Purpura (HSP) vasculitis?

Treatment of Henoch-Schönlein Purpura (HSP) Vasculitis

Most HSP cases are self-limited and require only supportive care with NSAIDs or acetaminophen for joint pain, while severe renal involvement (persistent proteinuria >1 g/day/1.73 m² or crescentic nephritis) requires ACE inhibitors/ARBs as first-line therapy, escalating to corticosteroids ± immunosuppression for nephrotic syndrome or deteriorating kidney function. 1

Initial Assessment and Risk Stratification

Immediately perform urinalysis with microscopy at diagnosis and at every follow-up visit to detect hematuria, proteinuria, red blood cell casts, and dysmorphic red blood cells indicating glomerular involvement. 1 Measure blood pressure, as hypertension signals more severe renal disease. 1 Obtain basic metabolic panel (BUN, creatinine) and complete blood count to assess renal function and rule out thrombocytopenia. 1

The diagnosis is clinical when palpable purpura is present plus at least one of: renal involvement (hematuria/proteinuria), arthralgia/arthritis, or abdominal pain. 1

Treatment Algorithm by Disease Severity

Mild Disease (Skin and Joint Involvement Only)

• Use acetaminophen (paracetamol) as first-line analgesic for joint pain and cutaneous symptoms, as it is safer than NSAIDs in patients with potential renal involvement. 1
• Avoid ketorolac (Toradol) and other NSAIDs due to risk of acute kidney injury, especially with pre-existing renal impairment. 1
• Consider oral prednisone 1-2 mg/kg daily for two weeks for acute, widespread flares with severe pain, particularly when pain control is inadequate with acetaminophen. 1
• For persistent purpura and pain, consider colchicine 1 mg/day for at least six months. 1
• A low-antigen-content (LAC) diet may improve symptoms when strictly followed for 4-8 weeks and can be used as supportive treatment. 1

Moderate Renal Disease (Persistent Proteinuria)

• Start ACE inhibitor or ARB therapy for persistent proteinuria in HSP nephritis, even though evidence is extrapolated from IgA nephropathy rather than HSP-specific trials. 1
• Target proteinuria to <1 g/day/1.73 m² rather than attempting complete normalization, which increases medication side effects without proven benefit. 1
• For children with persistent proteinuria >1 g/day per 1.73 m² after ACE inhibitor/ARB trial and GFR >50 ml/min per 1.73 m², initiate a 6-month course of corticosteroid therapy. 1

Severe Renal Disease (Crescentic HSP with Nephrotic Syndrome or Deteriorating Kidney Function)

• Treat with high-dose intravenous methylprednisolone plus cyclophosphamide, following the same protocol as crescentic IgA nephropathy. 1
• When cyclophosphamide is contraindicated or causes side effects, alternative immunosuppressive options include azathioprine, cyclosporine, tacrolimus, or mycophenolate mofetil/mycophenolic acid. 1
• Cyclophosphamide is used less frequently due to side effects but remains standard for severe disease. 1

Severe Gastrointestinal Involvement

• For severe gastrointestinal HSP with poor response to steroids, mycophenolate mofetil has demonstrated effectiveness in inducing and maintaining remission. 2
• This approach is particularly useful for persistent, recurrent, or complicated HSP when steroid treatment fails. 2

Cardiac Involvement (Rare but Life-Threatening)

• For HSP with cardiac involvement (LV dysfunction, bradycardia, AV block), initiate rituximab 375 mg/m² weekly for 4 weeks plus corticosteroids, especially when cyclophosphamide is contraindicated due to acute renal failure. 3
• Cardiac involvement carries high morbidity and mortality, requiring early aggressive immunosuppressive therapy. 3

Critical Management Principles

What NOT to Do

• Do NOT use corticosteroids prophylactically at HSP onset to prevent nephritis—moderate quality evidence (Level 1B) shows no benefit in preventing nephritis or reducing risk of severe persistent nephritis. 1
• Do NOT start corticosteroids too early for mild proteinuria without adequate trial of ACE inhibitor/ARB therapy, as this increases side effects without proven benefit. 1
• Do NOT delay urinalysis—perform at every visit to screen for infection, renal relapse, or bladder complications. 4

Adult HSP Considerations

• Treat adults with HSP nephritis using the same approach as children, though adults have worse prognosis and higher risk of progression to end-stage renal disease. 1
• HSP is rare in adults but often more serious with more frequent and severe nephritis. 5

Long-Term Monitoring and Prognosis

• Monitor for persistent hematuria and proteinuria at every visit, as these indicate ongoing disease activity. 1
• Short-term outcome depends on severity of gastrointestinal manifestations, while long-term prognosis depends on presence and severity of nephritis. 5
• Studies with prolonged follow-up show that up to one-third of patients may reach end-stage renal failure, making vigilant renal monitoring essential. 5

Common Pitfalls to Avoid

• Delaying treatment in rapidly deteriorating patients while waiting for biopsy results. 6
• Using NSAIDs in patients with any degree of renal involvement. 1
• Attempting to normalize proteinuria to <0.5 g/day/1.73 m², which increases side effects without proven benefit. 1
• Failing to perform urinalysis at every clinical visit. 4, 1