Early diagnosis of necrotizing fasciitis by utilization of ultrasonography.

Necrotizing fasciitis is a rare and rapid progression soft tissue infection. The only identifiable feature is tissue necrosis along a single fascia plane. Because the skin is initially spared, it is difficult for early recognition prior to extensive tissue destruction. Ultrasonography was used for early diagnosis of this infection in five cases. All 5 patients presented with severe cellulitis. Under the suspicion of necrotizing fasciitis, ultrasonography was performed before surgical debridement. Tissue biopsy was done for histological confirmation of the diagnosis. Three patients were proven to have necrotizing fasciitis and two cellulitis only. The ultrasonographic findings of necrotizing fasciitis included: 1) irregularity of the fascia; 2) abnormal fluid collections along the fascia plane; and 3) diffuse thickening of the fascia when compared with the control site in the normal limb. However, in severe infectious cellulitis, the above mentioned findings were not observed. Our results indicate the usefulness of the ultrasonography for early diagnosis of necrotizing fasciitis.