Maverakis et al reported diagnostic criteria for ulcerative pyoderma gangrenosum (PG). This is based on a Delphi consensus of international experts. The experts are from multiple institutions in North America and Europe.
Patient selection: ulcerative lesion suspicious for pyoderma gangrenosum
Major criterion:
(1) biopsy of the ulcer edge shows a neutrophilic infiltrate
Minor criteria:
(1) exclusion of infection
(2) pathergy (lesion develops at the site of an intradermal prick from a sterile needle)
(3) history of inflammatory bowel disease or inflammatory arthritis
(4) history of papule, pustule or vesicle ulcerating within 4 days of appearance
(5) peripheral erythema, undermining border and tenderness at the ulcer
(6) multiple ulcers with at least 1 on the anterior lower leg (pretibial)
(7) ulcer heals with a cribriform or "wrinkled paper" scar
(8) decrease in ulcer size within 1 month of starting immunosuppressive therapy
A diagnosis of ulcerative PG can be made if the major criterion and >= 4 of the minor criteria are present.
Performance:
• The sensitivity is 86% and specificity 90%.
• The reported area under the ROC curve is 0.94.r
