Leukocytoclastic vasculitis

Background

• Histopathologic description of a small-vessel vasculitis, typically of the skin
• Includes cutaneous leukocytoclastic angiitis and cutaneous arteritis

Etiology

• Idiopathic in 50%
• Infections
  • Post-infectious sequela of streptococcal pharyngitis
  • Mycobacterium, Staphylococcus aureus, Chlamydia, Neisseria, and HIV
  • Chronic hepatitis B, hepatitis C, and syphilis
• Drugs, typically with onset 1 to 3 weeks after starting
  • Antibiotics: beta lactams, erythromycin, clindamycin, vancomycin, sulfonamides
  • Others: furosemide, allopurinol, NSAIDs, amiodarone, gold, thiazides, phenytoin, beta blockers, TNF-alpha inhibitors, SSRIs, metformin, warfarin, valproic acid
• Neoplastic: lymphoma, leukemia, colorectal adenocarcinoma, lung cancer
• Autoimmune diseases
  • Systemic lupus erythematosus
  • Sjogren syndrome
  • IBD
  • Behcet disease
  • Rheumatoid arthritis
  • Cryoglobulinemic vasculitis
  • IgA vasculitis
  • Hypocomplementemic urticarial vasculitis
  • Erythema elevatum diutinum

Investigations

• Biopsy
• If systemic involvement, get ANA, ENA, ANCA, C3/C4, RF, cryoglobulins, SPEP, aPTT, hepatitis B, hepatitis C, and HIV
• Second-line investigations include cryofibrinogen, lupus anticoagulant, anti-B2-glycoprotein, anti-cardiolipin, and-dsDNA, anti-CCP, serum IgA levels, celiac testing, cold agglutinins, echocardiography, blood and urine cultures