Pyoderma gangrenosum

Background

Associated Disorders

• Inflammatory bowel disease (40%)
• Inflammatory arthritis (20%)
• Solid organ malignancy (5-10%)
• Hematologic malignancy (5-10%)
• Other hematologic disorder (5%), including MGUS, myelodysplastic syndrome, or polycythemia vera

Diagnosis

Diagnostic Criteria

• Major criterion:
  • Biopsy of ulcer edge demonstrating a neutrophilic infiltrate
• Minor criteria:
  • Exclusion of infection
  • Pathergy
  • Personal history of inflammatory bowel disease or inflammatory arthritis
  • History of papule, pustule, or vesicle that rapidly ulcerated
  • Peripheral erythema, undermining border, and tenderness at site of ulceration
  • Multiple ulcerations (at least one occurring on an anterior lower leg)
  • Cribriform or "wrinkled paper" scar(s) at sites of healed ulcers
  • Decrease in ulcer size within one month of initiating immunosuppressive medications
• Interpretation:
  • Positive if at the major criterion and at least four minor criteria are present