Abstract
BACKGROUND: Necrotizing soft tissue infection caused by Group A β-hemolytic Streptococcus (GAS) requires early recognition and intervention due to its rapid progression and high mortality. While rapid antigen detection testing (RADT) is primarily designed for GAS pharyngitis diagnosis, its utility in necrotizing soft tissue infections remains limited. CASE PRESENTATION: This series presents three cases of GAS necrotizing soft tissue infection in which RADT provided adjunctive diagnostic information that contributed to surgical management decisions. RADT positivity, combined with clinical findings, facilitated immediate extensive debridement in one case, prompted additional surgical exploration despite the absence of obvious fascial necrosis in another, and provided supportive data for early intervention when local findings worsened in the third case. All patients survived with limb preservation. CONCLUSIONS: While the utility of GAS RADT in necrotizing soft tissue infections is not yet established, this case series suggests its potential value as adjunctive diagnostic information that may contribute to decisions regarding extensive debridement, additional incisions, or the need for careful wound monitoring in anticipation of developing necrosis.