What is the recommended workup and management for pediatric Henoch-Schönlein Purpura (HSP)?

Workup of Pediatric Henoch-Schönlein Purpura

All children presenting with suspected HSP require urinalysis, blood pressure measurement, serum creatinine, and BUN at initial presentation, with mandatory 6-month monitoring regardless of initial findings. 1

Initial Diagnostic Workup

Essential Laboratory Tests at Presentation

• Urinalysis with microscopy to detect hematuria and proteinuria (present in 54% at onset) 1, 2
• Blood pressure measurement to identify hypertension, particularly in adolescents who have higher risk of severe renal involvement 1
• Serum creatinine and BUN to assess baseline renal function, especially critical in adolescents 1
• Complete blood count to evaluate for thrombocytopenia and anemia from GI bleeding 3
• Erythrocyte sedimentation rate (ESR), as elevated levels (present in 57% of cases) correlate with increased recurrence risk 2
• Serum IgA levels, elevated in 37% of cases, though not required for diagnosis 2

Clinical Diagnostic Criteria

The diagnosis requires palpable purpura PLUS at least one of the following: diffuse abdominal pain, arthritis/arthralgia, renal involvement (hematuria/proteinuria), or biopsy showing predominant IgA deposition 4. The purpura is the presenting symptom in 74% of cases, with arthritis in 15% and abdominal pain in 12% 2.

Risk Stratification Based on Day 7 Urinalysis

A normal urinalysis on day 7 has a 97% negative predictive value for normal renal outcome, making this the critical decision point for monitoring intensity 5.

High-Risk Features Requiring Intensive Monitoring

• Abnormal urinalysis on day 7 (proteinuria or hematuria) 5
• Adolescent age (mean age 12.3 years in those requiring renal referral vs. 6.0 years with normal outcome) 1, 5
• Decreased renal function at presentation (requires immediate renal biopsy) 6
• Nephrotic syndrome or nephritic syndrome at presentation (requires immediate renal biopsy) 6

When to Perform Renal Biopsy

Renal biopsy is indicated immediately for: decreased renal function at presentation, severe nephrotic syndrome, or nephritic syndrome 6. Biopsy should also be considered for persistent heavy proteinuria during follow-up 6.

Monitoring Protocol

All Patients (Minimum 6-Month Duration)

• Urinalysis at days 7,14,30,60,90, and 180 1, 3
• Blood pressure measurement at each visit 1, 3
• Serum creatinine if any urinary abnormalities develop 1

Intensified Monitoring for High-Risk Patients

Children with abnormal day 7 urinalysis require weekly urinalysis and blood pressure checks until normalization, then continue standard monitoring schedule 5.

Additional Workup Considerations

When Diagnosis is Uncertain

• Skin biopsy showing leukocytoclastic vasculitis with IgA deposition increases diagnostic specificity 7
• Stool guaiac testing if abdominal pain present (GI involvement occurs in 51%) 2
• Scrotal ultrasound if scrotal pain/swelling in males (occurs in 13%) 2
• Abdominal ultrasound if severe abdominal pain to exclude intussusception (occurs in 0.6%) 2

Laboratory Tests NOT Routinely Recommended

• Complement levels (C3, C4) are typically normal and not diagnostically useful 3
• ANCA testing is not indicated unless atypical features suggest alternative vasculitis 7
• Coagulation studies unless bleeding complications occur 3

Critical Pitfalls to Avoid

Do NOT skip the day 7 urinalysis, as this is the single most important prognostic indicator and determines monitoring intensity 5.

Do NOT assume normal initial urinalysis means no risk, as renal involvement can develop later—46% show initial renal inflammation, and mandatory 6-month monitoring is required for all patients 5.

Do NOT use prophylactic corticosteroids at HSP onset to prevent nephritis, as moderate-quality evidence (Grade 1B) shows this is ineffective 6, 1.

Do NOT delay renal biopsy in patients with decreased renal function at presentation, as crescentic disease requires immediate aggressive immunosuppressive therapy 1.

Special Considerations for Adolescents

Adolescents require more aggressive initial workup including mandatory serum creatinine and BUN, as they have significantly worse outcomes with higher rates of severe renal involvement, persistent nephritis, and 1-5% risk of progression to end-stage renal disease 1.

Long-Term Follow-Up

Women with childhood HSP history require close monitoring during pregnancy for proteinuria and hypertension complications 3. All patients should have final assessment at 6 months minimum, with continued follow-up if any urinary abnormalities persist 3, 5.