Pyoderma gangrenosum--a postoperative "pseudo-infection".

Pyoderma gangrenosum is a skin ulcerative necrosis, due to dermal neutrophilic infiltration, through a non-infectious exacerbation of cell -mediated immunity. Being characterized by pathergy, the disease may be triggered by surgery; in this case, it is easily mistaken for a postoperative infection. We report a case of pyoderma gangrenosum after coronary artery bypass surgery. The patient developed, from the 7th postoperative day, around the incisions, dermo-epidermic lesions specific for the disease, high fever with chills and a severe biological inflammatory syndrome. Treatment for wound sepsis was ineffective. After pyoderma gangrenosum was recognized, corticosteroids (Prednisone 80 mg/d) led, in two days time, to a spectacular improvement, and in 7 weeks, to complete epithelization of the lesions. If after debridement of a supposedly infected wound (with pustules, bullae or ulcerations), there is no improvement, but a centrifugal extension of the lesions, with a "sepsis-like" syndrome and persistent negative cultures, one should think at pyoderma gangrenosum; in that case, not the antibiotics, but corticosteroids (or other immunosuppressants) are the treatment.