What is the initial approach to managing Henoch-Schönlein Purpura (HSP) in a 16-year-old girl?

Initial Management of Henoch-Schönlein Purpura in a 16-Year-Old Girl

For a 16-year-old girl with HSP, begin with supportive care and immediately assess for renal involvement through urinalysis, blood pressure, and renal function tests, as renal disease determines long-term morbidity and mortality. 1, 2

Immediate Clinical Assessment

• Confirm the diagnosis by documenting the characteristic palpable purpuric rash on lower extremities (present in 100% of cases), and assess for the classic triad: arthritis (75%), abdominal pain (60-65%), and renal involvement (40-50%). 1
• Obtain baseline urinalysis on presentation to detect proteinuria and hematuria, as 46% of children develop initial renal inflammation. 3
• Measure blood pressure and obtain serum creatinine and BUN, as adolescents are at higher risk for severe renal involvement compared to younger children. 4, 5
• Check for red blood cell casts in urine microscopy, which indicates glomerulonephritis requiring more aggressive monitoring. 5

Risk Stratification Based on Age

• Recognize that adolescents have worse outcomes than younger children, with higher rates of severe renal involvement, persistent nephritis, and progression to end-stage renal disease (1-5% overall). 4, 1
• Older patients require more intensive monitoring, as those requiring renal referral average 12.3 years old versus 6.0 years for those with normal outcomes (p<0.01). 3

Initial Treatment Approach

Supportive Care (First-Line for All Patients)

• Provide NSAIDs for joint pain and symptomatic relief, as HSP spontaneously resolves in 89-94% of cases without specific intervention. 1
• Monitor closely but avoid corticosteroids for preventing nephritis, as moderate-quality evidence shows they do not prevent renal involvement or decrease risk of severe persistent nephritis (Grade 1B recommendation). 4

When to Escalate to Corticosteroids

• Do NOT use corticosteroids prophylactically at HSP onset, even in adolescents. 4
• Consider oral prednisone 1-2 mg/kg daily for 2 weeks only for severe abdominal pain or arthritis causing significant morbidity, as this reduces mean time to symptom resolution. 1
• Reserve corticosteroid therapy for renal involvement only after documenting nephrotic-range proteinuria (>3.5 g/day or >40 mg/m²/hour) that has not improved after a trial of ACE inhibitor or ARB therapy. 4

Renal Monitoring Protocol

Day 7 Assessment (Critical Decision Point)

• Repeat urinalysis on day 7, as a normal result has 97% negative predictive value for normal renal outcome. 3
• If urinalysis is normal on day 7, continue standard 6-month monitoring with monthly urine checks and blood pressure measurements. 3
• If urinalysis shows proteinuria or hematuria on day 7, intensify monitoring to weekly urine checks for the first month, then biweekly for 6 months. 3

Indications for Renal Biopsy

• Perform renal biopsy if the patient presents with decreased renal function (elevated creatinine), severe nephrotic syndrome, or nephritic syndrome at initial presentation. 4
• Obtain biopsy for persistent heavy proteinuria (>1 g/day/1.73 m²) during follow-up despite ACE inhibitor/ARB therapy. 4

Treatment of HSP Nephritis

Mild Proteinuria (Non-Nephrotic Range)

• Initiate ACE inhibitor or ARB for persistent significant proteinuria, targeting reduction to <1 g/day/1.73 m² (not <0.5 g/day/1.73 m², as this increases side effects without proven benefit). 4
• Trial angiotensin blockade for 8-12 weeks before considering corticosteroids. 4

Nephrotic-Range Proteinuria

• Start corticosteroid therapy only if nephrotic-range proteinuria persists after adequate trial of ACE inhibitor/ARB (8-12 weeks). 4
• Use oral prednisone at immunosuppressive doses (specific dosing extrapolated from IgA nephropathy protocols). 4

Crescentic HSP Nephritis (Most Severe)

• Administer high-dose intravenous methylprednisolone immediately for crescentic HSP with nephrotic syndrome and/or deteriorating kidney function. 4, 5
• Add cyclophosphamide as the only immunosuppressive agent with RCT evidence for crescentic HSP nephritis in children. 4, 5
• Consider cyclosporine for heavy proteinuria with crescentic disease, though long-term outcomes are not superior to IV corticosteroids and nephrotoxicity limits use in relapse. 4

Monitoring for Severe Complications in Adolescents

Gastrointestinal Complications

• Monitor for severe abdominal pain, bloody stools, or acute anemia, as adolescents can develop GI bleeding from terminal ileum involvement or Meckel's diverticulum. 5
• Check fecal occult blood if patient develops syncope or hemoglobin drops significantly. 5
• Consider capsule endoscopy if EGD is negative but GI bleeding suspected. 5

Cardiac Complications (Rare but Serious)

• Obtain EKG if patient reports palpitations or dizziness, as HSP cardiac vasculitis can cause atrial fibrillation or non-sustained ventricular tachycardia. 5
• Treat arrhythmias with anti-arrhythmic drugs (metoprolol, amiodarone) and intensify immunosuppression. 5

Neurological Complications (Rare)

• Assess for proximal muscle weakness, tremors, or clonus, which may indicate neurological vasculitis requiring aggressive immunosuppression. 5

Follow-Up Protocol

• Monitor ALL patients for minimum 6 months with regular urinalysis, blood pressure checks, and renal function tests, regardless of initial severity. 2, 3
• Counsel female patients that they are at increased risk for proteinuria and hypertension during future pregnancies and require close obstetric monitoring. 2
• Reassess at 6 months to determine if extended monitoring is needed based on persistent urinary abnormalities. 2, 3

Critical Pitfalls to Avoid

• Do not give prophylactic corticosteroids at HSP onset to "prevent" nephritis—this is ineffective and exposes patients to unnecessary steroid side effects. 4
• Do not delay renal biopsy in patients with decreased renal function at presentation, as crescentic disease requires immediate aggressive therapy. 4, 5
• Do not assume HSP is benign in adolescents—they have higher rates of severe complications including cardiac, neurological, and renal involvement compared to younger children. 5, 1
• Do not stop monitoring at 3 months—renal involvement can develop or worsen throughout the 6-month follow-up period. 2, 3