A Case of Suspected Pit Viper Bite in Rural Nepal: Lessons for Snakebite Care

Pit viper envenoming is common across South Asia. Indian polyvalent antivenom (ASV) does not neutralise pit viper venom. Given the inherent uncertainty in snake species identification, the World Health Organisation (WHO) recommends a syndromic approach to guide ASV use. A 59-year-old woman was bitten on her right ring finger while cutting grass in the Terai farmland of eastern Nepal. Within one hour, she developed hand and forearm oedema with no bleeding or signs of neurotoxicity. Initial coagulation was normal: the 20-minute whole blood clotting test (20WBCT) clotted, prothrombin time (PT) was 12.4 seconds and international normalised ratio (INR) was 1.0. Urinalysis showed no haematuria. Ten vials of ASV were administered at a peripheral treatment centre with no immediate reaction. She was transferred to a tertiary hospital where she received intravenous (IV) fluids and analgesia and was monitored for three days. No coagulopathy developed on serial testing. The presentation suggested pit viper envenoming, for which ASV is ineffective, so administration of ASV added an avoidable anaphylaxis risk. Snake colour reports can inform, but are insufficient to guide treatment. Management should be syndrome-led, informed by local ecology and based on serial coagulation testing. Clear transfer thresholds and avoidance of bleeding risk practices (intramuscular injections and non-steroidal anti-inflammatory drugs) are vital. System measures, including procurement of antivenom stocks aligned to local snakes, audit, community education and organised transport support early assessment and reduce non-beneficial ASV use. In snakebite where species identification is uncertain, syndromic management guides treatment and reduces iatrogenic harm.