Pyoderma Gangrenosum vs Malignant Pyoderma

Abstract

In 1930, Brunsting et al¹ first described the clinical entity of pyoderma gangrenosum (PG) with a report of five cases. Four of these patients had associated ulcerative colitis and the fifth had empyema. In PG the primary skin lesions are often sterile pustules, but vesicles, bullae, nodules, or plaques may precede the typical ulcerations; conversely, primary lesions may be absent altogether or ulcers may follow trauma (pathergy), as noted in four of the original five patients.¹ Single or usually multiple ulcerations of variable size rapidly supersede the early lesions and may enlarge slowly or rapidly. Their borders are sharply defined, serpiginous, and often edematous, violaceous, and extensively undermined. The ulcer margins may be studded with pustules or vesicles and are surrounded by an erythematous zone. The ulcer base is purulent, exudative, and covered with debris and granulation tissue. Cribriform scarring is a frequent