Azemiops feae (Fea's Viper) Envenoming: A Case Report and Review of the Literature

Azemiops feae (Fea's viper) is a phylogenetically distinctive Asian viper with poorly defined medical significance, and human envenomations remain rarely reported in the English-language literature. We describe a new case of A. feae envenoming from Chongqing, China, and present a scoping review of published clinical case reports and case series to better characterize its epidemiology, clinical manifestations, and management. A 53-year-old male developed marked local pain and swelling following a bite to the hand, accompanied by transient neurotoxic symptoms, as well as mild hypofibrinogenemia. Treatment with a single vial of Gloydius brevicaudus monovalent antivenom was followed by clinical improvement and full recovery. Review of the literature identified nine previously published studies from China and one captive case from Europe. Envenoming typically occurred during agricultural activities, most commonly affected the lower extremities, and was characterized by prominent local effects with occasional mild neurotoxic features and inconsistent, generally mild coagulation abnormalities. Antivenom use was highly variable, involving multiple heterologous monovalent antivenoms, and outcomes were uniformly favourable regardless of antivenom administration. Collectively, available evidence indicates that A. feae envenoming is usually self-limited, with predominantly local effects and infrequent, mild systemic involvement. However, the absence of species-specific antivenom and the heterogeneity of current treatment practices highlight the need for systematic venom characterization and functional antivenom efficacy studies to inform evidence-based clinical management.