Severe venom-induced consumption coagulopathy, snakebite-associated thrombotic microangiopathy, and local necrosis following Western Bush Viper (Atheris chlorechis) envenoming in France

Severe venom-induced consumption coagulopathy, snakebite-associated thrombotic microangiopathy, and local necrosis following Western Bush Viper (Atheris chlorechis) envenoming in France

Abstract

Background

Atheris spp. are small African vipers whose bites are rarely reported but can result in significant envenoming. There is no specific antivenom available. We describe a case of systemic A. chlorechis envenoming presenting with venom-induced consumption coagulopathy (VICC), snakebite-associated thrombotic microangiopathy (TMA), and local necrosis.

Case presentation

A 33-year-old man was bitten on the index finger by a captive A. chlorechis. Within 6 hours, early laboratory abnormalities progressed to VICC with markedly prolonged PT/aPTT, undetectable fibrinogen, elevated fibrin monomers, and factor V deficiency. Despite the administration of four vials of Inoserp™ Pan-Africa and repeated transfusions of fibrinogen and fresh frozen plasma, the patient continued to exhibit signs of coagulopathy for 48 hours. Thrombocytopenia, anaemia, schistocytes, and hyperbilirubinemia indicated snakebite-associated TMA, which resolved spontaneously without renal involvement. Progressive local necrosis developed on the finger and dorsal hand, ultimately requiring amputation of the proximal phalanx and surgical debridement.

Conclusion

This case demonstrates that A. chlorechis envenoming can produce both local and systemic toxicity. The absence of clinical improvement after Inoserp™ Pan-Africa is consistent with preclinical data showing limited cross-neutralization against Atheris venoms. Administration of clotting factors in the presence of unneutralised procoagulant toxins may have contributed to the development of TMA. Therefore, fresh frozen plasma and fibrinogen should be reserved for cases of coagulopathy with active bleeding or when an invasive procedure is being considered, particulary in the absence of a concomitant effective antivenom. The local necrosis highlights the potential for significant local sequelae, necessitating cautious but timely surgical intervention.

Larréché, S., Le Roux, G., Chippaux, J., Hardy, J., Fédou, A., & Labadie, M. (2026). Severe venom-induced consumption coagulopathy, snakebite-associated thrombotic microangiopathy, and local necrosis following Western Bush Viper (Atheris chlorechis) envenoming in France. Toxicon, 109021. https://doi.org/10.1016/j.toxicon.2026.109021