Successful treatment of necrotizing fasciitis associated with diabetic nephropathy

A 50-year-old woman with a 15-year history of type 2 diabetes mellitus was admitted to our hospital due to high fever and a skin lesion with severe pain, swelling and a sensation of heat in the right thigh. Laboratory examination showed elevated C-reactive protein (CRP), thrombocytopenia, nephrotic syndrome and renal dysfunction. Her blood glucose level had been well controlled. Streptococcus agalactiae was detected in both the skin lesion and blood culture, and pathological examination revealed neutrophil infiltration in the fascia and muscle layer. The patient was diagnosed with necrotizing fasciitis, septic shock and disseminated intravascular coagulation. A combination therapy of antibiotics and surgical debridement resulted in the improvement of symptoms as supported by laboratory findings, and the skin lesion also showed improvement. Although group A streptococcus is well known to be implicated in the pathogenesis of necrotizing fasciitis, only S. agalactiae, belonging to group B streptococcus, was isolated from the tissue and blood cultures in this case. Although this organism is not virulent and rarely causes a necrotizing fasciitis, both the superficial fascial layer and underlying muscle were affected in this case. There have been only a few reports of necrotizing fasciitis due to S. agalactiae in patients with diabetes mellitus. Although the blood glucose level was well controlled in our patient, this disease might be caused by other factors, including diminished sense of touch and pain, abnormality of microcirculation and hypogammaglobulinemia due to nephrotic syndrome.