Periorbital Necrotizing Fasciitis Mimicking Allergic Oedema: A Diagnostic Pitfall

Periorbital necrotizing fasciitis is a rare, rapidly progressive, and potentially life-threatening infection that may initially resemble benign conditions, resulting in delayed recognition. We report the case of a 74-year-old woman who presented with progressive palpebral oedema, which she initially attributed to an allergic reaction. Prior to hospital admission, she had received oral prednisolone 32 mg/day for two days. On hospital admission, marked right upper eyelid oedema, induration, purulent discharge, necrotic cutaneous changes, and systemic signs of infection were present. Laboratory evaluation demonstrated leukocytosis and markedly elevated C-reactive protein, while imaging revealed extensive periorbital soft-tissue involvement. Broad-spectrum intravenous antimicrobial therapy was initiated, and blood and tissue cultures subsequently grew Streptococcus pyogenes. Repeated surgical debridement resulted in progressive clinical improvement, with near-complete restoration of eyelid function during follow-up. This case illustrates the diagnostic challenge of early periorbital necrotizing fasciitis and emphasizes the importance of considering this diagnosis when periorbital inflammation progresses rapidly or develops necrotic or systemic features, even when the initial presentation suggests a benign condition.