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.



• The sensitivity is 86% and specificity 90%.

• The reported area under the ROC curve is 0.94.r

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