The value of bacteriology and serology in the diagnosis of necrotizing fasciitis.

Fourteen patients with necrotizing fasciitis are described. In thirteen the cause was Streptococcus pyogenes [Group A beta haemolytic streptococcus (BHS)]; in the fourteenth, Staphylococcus aureus was responsible. In the acute fulminating form of the disease, BHS can be cultured from the affected tissues. In the less acute form, particularly when the patient has been previously treated with antibiotics, other bacteria colonize the tissues and the BHS cannot be isolated. Serological evidence of infection with Streptococcus pyogenes can be ascertained in all such patients by finding high levels of anti-desoxyribonuclease B and anti-hyaluronidase. Measurement of the anti-streptolysin O titre is not helpful. Once the diagnosis is made, surgical removal of all necrotic tissue is still the treatment of choice.