Necrotizing fasciitis caused by Serratia marcescens in two patients receiving corticosteroid therapy

Necrotizing fasciitis (NF), a devastating soft tissue infection, is rarely attributed to Serratia marcescens. We here report two patients with S. marc escens NF, both of whom had underlying renal disease and had been receiving corticosteroid therapy. The first patient, a 40-year-old man with systemic lupus erythematosus and uremia on prednisolone therapy, developed fulminan t cellulitis and septic shock 1 month after a skill biopsy for cutaneous va sculitis of the left foot. The cellulitis evolved to NF, and blood and necr otic tissue cultures both grew S. marcescens. The patient completely recove red after debridement and ceftazidime therapy. The second patient, a 73-yea r-old man receiving prednisolone therapy for nephrotic syndrome, developed light leg cellulitis that evolved to NF. Blood and necrotic tissue cultures both grew S. marcescens. After aggressive debridement and ciprofloaxcin th erapy, the NF improved. However, the patient died of aspiration pneumonia a nd massive gastrointestinal bleeding 1 month later. These findings illustra te that S. marcescens should be considered as a potential pathogen causing NF in susceptible hosts.