Table 2.

Proposed diagnostic criteria for classic ulcerative pyoderma gangrenosum, according to Su et al,⁴ diagnosis would require two major and at least two minor criteria

Major criteria

– Rapid progression of a painful, necrolytic, cutaneous ulcer with an irregular, violaceous, and undermined border.

– Exclusion of other causes of cutaneous ulceration.

Minor criteria

– History suggestive of pathergy.

– Clinical finding of cribriform scarring.

– Systemic diseases associated with pyoderma gangrenosum.

– Histopathologic findings (sterile dermal neutrophilic infiltration, ± mixed inflammation, ± lymphocytic vasculitis).

– Treatment response (rapid response to systemic steroid treatment).

Note: Copyright © 2004. John Wiley and Sons. Adapted from Su WP, Davis MD, Weenig RH, Powell FC, Perry HO. Pyoderma gangrenosum: clinicopathologic correlation and proposed diagnostic criteria. Int J Dermatol. 2004;43(11):790–800.⁴