Henoch-Schönlein Purpura (IgA Vasculitis): A Comprehensive Clinical Review

Henoch-Schönlein Purpura (HSP), now termed IgA Vasculitis, is the most common systemic vasculitis in children. It is characterized by IgA-mediated small vessel vasculitis affecting the skin, gastrointestinal tract, joints, and kidneys. This comprehensive review provides medical professionals with current evidence-based information on the pathogenesis, clinical manifestations, and management of HSP.

Epidemiology

• Age Distribution:
  • Peak incidence: 4-6 years
  • 90% of cases occur in children under 10 years
  • Can occur in adults (more severe manifestations)
• Demographics:
  • Slight male predominance
  • More common in Caucasians
  • Seasonal variation (peak in winter)
• Incidence:
  • 13-20 cases per 100,000 children annually
  • Lower incidence in adults

Pathophysiology

1. Immunological Mechanisms:
   • IgA immune complex deposition
   • Activation of alternate complement pathway
   • Neutrophil infiltration
   • Small vessel vasculitis
2. Triggering Factors:
   • Upper respiratory infections
   • Group A streptococcus
   • Viral infections
   • Medications
   • Vaccines
   • Insect bites

Clinical Manifestations

Cutaneous Manifestations

• Characteristic Features:
  • Palpable purpura
  • Symmetrical distribution
  • Predominantly on lower extremities and buttocks
  • Gravity-dependent areas

Articular Involvement

• Characteristics:
  • Arthralgia or arthritis
  • Non-migratory
  • Non-deforming
  • Large joints predominantly affected

Gastrointestinal Manifestations

• Symptoms:
  • Abdominal pain (colicky)
  • Gastrointestinal bleeding
  • Intussusception risk
  • Bowel perforation (rare)

Renal Involvement

• Manifestations:
  • Hematuria
  • Proteinuria
  • Nephritis
  • Nephrotic syndrome
• Long-term Implications:
  • Risk of chronic kidney disease
  • Need for monitoring

Diagnostic Approach

Clinical Criteria (EULAR/PRINTO/PRES)

1. Mandatory Criterion:
   • Palpable purpura
2. Additional Criteria (minimum 1):
   • Abdominal pain
   • Histopathology showing IgA deposition
   • Arthritis or arthralgia
   • Renal involvement

Laboratory Investigations

• Basic Studies:
  • Complete blood count
  • Coagulation profile
  • Renal function tests
  • Urinalysis
• Additional Testing:
  • Serum IgA levels
  • Complement levels
  • Stool guaiac test
  • Skin biopsy (if diagnosis unclear)

Management Strategies

Supportive Care

• Rest during acute phase
• Adequate hydration
• Pain management
• Joint protection

Pharmacological Interventions

1. Pain and Inflammation:
   • NSAIDs for joint symptoms
   • Acetaminophen for pain
2. Severe Cases:
   • Corticosteroids
     • Severe abdominal pain
     • Significant joint involvement
     • Severe kidney disease

Renal Disease Management

• Monitoring Protocol
• ACE inhibitors/ARBs for proteinuria
• Immunosuppressive therapy for severe cases
  • Cyclophosphamide
  • Azathioprine
  • Mycophenolate mofetil

Complications

• Acute Complications:
  • Intussusception
  • Gastrointestinal bleeding
  • Bowel perforation
  • Acute kidney injury
• Long-term Complications:
  • Chronic kidney disease
  • Hypertension
  • End-stage renal disease (rare)

Monitoring and Follow-up

1. Acute Phase:
   • Daily urinalysis
   • Blood pressure monitoring
   • Abdominal examination
2. Long-term Follow-up:
   • Monthly urinalysis for 6 months
   • Blood pressure checks
   • Renal function monitoring

Prognosis

• General Outcomes:
  • Self-limiting in most cases
  • Resolution within 4-8 weeks
  • Recurrence in 33% of cases
• Prognostic Factors:
  • Age at onset
  • Severity of renal involvement
  • Presence of nephrotic syndrome

Special Considerations

• Adult-onset Disease:
  • More severe presentation
  • Higher risk of renal complications
  • Worse prognosis
• Pregnancy:
  • Risk of exacerbation
  • Need for close monitoring

Conclusion

Henoch-Schönlein Purpura is generally a self-limiting condition in children, but careful monitoring is essential to identify and manage potential complications, particularly renal involvement. Understanding the varied presentations and potential complications is crucial for optimal patient care.

Date of last update: December 2024