Henoch–schönlein Purpura

Description

IgA vasculitis

Etiology

• Mechanism: Increased serum IgA complexes with vascular deposition, activation of alternative complement pathway:
  • Glomerular mesangial deposition can cause mesangial proliferation to glomerulonephritis with crescent formation
• Although cause is undefined, there are many associated conditions:
  • Infectious (Group A strep, Mycoplasma, Varicella, Epstein–Barr)
  • Drugs: Penicillin, tetracycline, aspirin, sulfonamides, erythromycin
  • Allergens: Insect bites, chocolate, milk, wheat
• Incidence: Primarily school-aged children and young adults, peak in 4–6 yr olds
• More common in whites
• Males > females
• Occurs more often in winter through early spring
• Multisystem involvement can lead to life-threatening or long-term complications:
  • Intussusception
  • Proliferative glomerulonephritis
  • Chronic renal failure: More common in older children and adults (13–14%), higher risk in patients with hematuria and nephrotic range proteinuria
  • Intracranial hemorrhage (rare)