Periorbital anthrax after soil-contaminated trauma mimicking necrotizing infection: a case report with diagnostic and reconstructive challenges

Periorbital cutaneous anthrax is an exceptionally rare clinical entity that closely mimics periocular necrotizing fasciitis, creating a significant diagnostic challenge. While most reported cases are zoonotic, this report details a 46-year-old male construction worker who developed fulminant periorbital anthrax 48 h after sustaining a soil-contaminated iron rod abrasion, without any known animal contact. He presented with high-grade fever, rapidly progressive periorbital necrosis, and massive non-pitting edema. The initial presentation mimicked necrotizing fasciitis, prompting staged surgical debridement and broad-spectrum antibiotics. Because prior empirical antibiotic therapy rapidly rendered bacterial cultures sterile, early Gram staining provided an important microbiological clue for initiating anthrax-directed therapy. Definitive diagnosis was established via real-time polymerase chain reaction (RT-PCR) confirming Bacillus anthracis through pagA and cap gene amplification. Definitive oculoplastic reconstruction with a full-thickness skin graft, performed 6 months later, successfully corrected the resulting cicatricial ectropion. This case highlights the critical importance of utilizing early Gram stains and molecular diagnostics in culture-negative scenarios to rapidly differentiate toxin-mediated anthrax from polymicrobial necrotizing fasciitis and to establish the appropriate therapeutic and surgical approach.