Ulcer bed infection

Abstract

We report a case of ulcer bed infection in an enlarging venous leg ulcer without clinical signs of cellulitis in the surrounding tissues. Signs of infection in the leg ulcer were: 1) cocci‐like structures and bacteria‐like rods around vessel walls in the viable ulcer bed, 2) vasculitis‐like inflammation of deeply situated vessels of the viable tissue, 3) Pseudomonas aeruginosa ‐specific antibodies in the serum (other than against exotoxin A), 4) extensive epidermolysis of normal human skin by the wound exudate in vitro , and 5) P. aeruginosa exotoxin A in the wound exudate (23 ng/ml). In an in vitro cell assay, the wound exudate was cytotoxic and rabbit antibodies to exotoxin A, but not a serine proteinase inhibitor, inhibited this cytotoxicity. P. aeruginosa exotoxin A might contribute to the pathogenesis of the ulcer enlargement. The ulcer improved after the third skin graft, probably mainly due to effective treatment with a long‐stretch compression bandage.