176. Viper envenomation with ocular neurotocic effects managed without antidote admiistration:a case report 39th International Congress of the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT) 21-24 May 2019, Naples, Italy

Along with the more common clinical features, European viper envenomations may rarely present with neurotoxic manifestations. Those include muscle weakness, drowsiness, paresthesia, dyspnea and ocular complaints among others. Ocular neurotoxicity as an indication for antidote administration is still debated In this case the management with supportive/symptomatic treatment was sufficient. CASE REPORT. In May 2018, a 19-­‐year old man was admitted to an external emergency unit 20 minutes after a viper bite on the proximal phalanges of the right hand. The Poison Control Centre (PCC) of Policlinico Umberto I Hospital – Sapienza University of Rome was contacted immediately. Local signs of envenomation with fang marks, and swelling of the hand were present. Initial lab work showed no abnormalities. In the following 2 hours edema extended to the middle forearm (Figure 1), and one episode of vomiting was registered. The patient was hydrated and analgesics administered. Four hours post-­‐bite, edema did not progress proximally, but weakness, vertigo and mild abdominal pain were reported. LeuKocytosis (17.0 × 109/L, 90% neutrophils) and increased creatinkinase (245 U/L) were present. The PCC provided two vials of Viper Venom Antitoxin (Biomed) with no indication to administer at this time, but to closely monitor patient for any systemic and neurological manifestations. Seven hours post-­ bite,the swelling was stable, abdominal pain and previous neurological symptomsm regressed, and left ptosis appeared. Laboratory exams showed persistence of leukocytosis (16.6 × 109/l), glucose 123 mg/dL and creatinkinase 216 U/L. The PCC recommended further monitoring. Eighteen hours post-­‐bite ptosis ameliorated, no systemic signs had developed. The patient was discharged 40 hours post-­‐bite with no ptosis, edema in regression and leucocytes towards normalization. This case report suggests the following observations: i) as previously reported, neurological manifestations due to neurotoxins in some viper species venom may be characterized by delayed onset (up to 24 hours, 4-­‐7 hours in this case), association with mild local effects and reversibility; ii) weakness and vertigo preceded the ocular signs, and resolved in about 3 hours; iii) symptomatic management and close monitoring might be the best approach in such cases, with antitoxin recommended as soon as rapid edema extension and/or severe systemic/neurological symptoms appear.