Necrotizing fasciitis due to group A streptococci: a clinicopathological study of six patients.

The recent worldwide appearance of invasive group A streptococcal infections has again called attention to streptococcal necrotizing fasciitis. However, in contrast to polymicrobial necrotizing fasciitis, the streptococcal form has not been thoroughly studied clinically. The objective of the study was to elucidate the characteristic features of recent cases of necrotizing fasciitis due exclusively to pure group A streptococci. We encountered six patients with these criteria at a single hospital in Japan during the last 12 years. A clinicopathological analysis was performed in these six patients. In three patients, the clinical signs and the laboratory findings were characteristic of systemic toxicity. In this group, the clinical presentation was a pale or blue-gray lesion associated with severe intravascular coagulation histologically involving the vessels in the lesion. In the three patients without signs of systemic toxicity, a swollen, erythematous skin lesion persisted for as long as one week; histologically, the intravascular coagulation within these lesions was mild. In clinicopathological terms, the entity in these six patients could be clearly classified as either fulminant or subacute. In the fulminant type, immediate surgical debridement of necrotic fascia is required; in the subacute type, incision and drainage alone are sufficient.