Henoch-Schönlein Purpura (HSP): Clinical Management
For patients presenting with HSP, immediate urinalysis with microscopy is essential to detect renal involvement, which occurs in 20-50% of cases and determines the treatment pathway—ranging from supportive care for mild disease to aggressive immunosuppression with high-dose methylprednisolone plus cyclophosphamide for crescentic nephritis with deteriorating kidney function. 1
Initial Diagnostic Approach
Clinical Diagnosis
The diagnosis of HSP is clinical and based on the presence of:
- Palpable purpura (non-thrombocytopenic, typically on lower extremities and buttocks) 1
- Renal involvement (hematuria and/or proteinuria) 1
- Arthralgia/arthritis (bilateral ankle swelling most common) 1
- Abdominal pain 1
The classic triad of hematuria, purpuric lesions, and ankle pain is specifically diagnostic. 1
Mandatory Initial Laboratory Evaluation
Every patient with suspected HSP requires:
- Urinalysis with microscopy to look for red blood cell casts and dysmorphic RBCs (indicating glomerular involvement) 1
- Quantification of proteinuria (spot urine protein-to-creatinine ratio or 24-hour collection) 1
- Basic metabolic panel including BUN and creatinine 1
- Complete blood count 1
- Blood pressure measurement (hypertension indicates more severe renal involvement) 1
Treatment Algorithm Based on Renal Involvement Severity
Mild Disease (Proteinuria <0.5 g/day per 1.73 m²)
- Supportive care only with close monitoring 1
- Acetaminophen for pain control (NOT NSAIDs, which can cause acute kidney injury in patients with renal involvement) 1
- Serial urinalysis to monitor for progression 1
Moderate Disease (Persistent Proteinuria 0.5-1 g/day per 1.73 m²)
- Start ACE inhibitor or ARB therapy 1
- Target proteinuria reduction to <1 g/day/1.73 m² 1
- Continue monitoring renal function 1
Significant Proteinuria (>1 g/day per 1.73 m² after ACE-I/ARB trial and GFR >50 ml/min per 1.73 m²)
- Consider 6-month course of corticosteroid therapy 1
- This is reserved for patients who fail to respond adequately to ACE-I/ARB 1
Severe Disease (Crescentic HSP with Nephrotic Syndrome and/or Deteriorating Kidney Function)
- High-dose intravenous methylprednisolone PLUS cyclophosphamide 1
- This represents the most aggressive intervention for life-threatening renal involvement 1
Indications for Renal Biopsy
Perform renal biopsy when:
- Decreased renal function at presentation 1
- Severe nephrotic syndrome (proteinuria >3.5 g/day) 1
- Nephritic syndrome 1
- Deteriorating kidney function despite initial management 1
Critical Management Pitfalls
What NOT to Do
DO NOT use corticosteroids prophylactically at HSP onset to prevent nephritis—moderate quality evidence (Level 1B) demonstrates no benefit from this approach. 1 Corticosteroids should only be used for established severe renal disease as outlined above.
DO NOT use NSAIDs (ketorolac/Toradol) for pain control in HSP patients with any renal involvement, as they can precipitate acute kidney injury. 1 Use acetaminophen as the first-line analgesic instead. 1
DO NOT delay imaging if an abdominal mass is palpable—this could represent separate pathology such as Wilms tumor, not just HSP-related findings. 1
DO NOT assume isolated hematuria requires no evaluation if other concerning features are present. 1
Monitoring and Follow-up
- Serial urinalysis to track proteinuria and hematuria 1
- Blood pressure monitoring as hypertension indicates progression 1
- Renal function tests (BUN, creatinine) to detect deterioration 1
- Patients with initial renal involvement require long-term follow-up as late progression can occur 1
Understanding HSP as Expected Disease Progression
Renal involvement in HSP represents expected disease progression rather than a separate diagnosis or complication—it occurs in 20-50% of children with HSP. 1 This understanding is important for counseling families and establishing appropriate monitoring protocols from the time of initial diagnosis.