Background Antivenom immunoglobulin is a medication made up of antibodies used to treat snake bites.

Purpose To describe the effectiveness and safety of snake antivenom in viper bites.

Material and methods A 44-year-old male patient affected by a viper bite in the third phalanx of the right upper limb visits the hospital Emergency Room. In the Outpatients Clinic, physicians have administered him steroids, antihistamines and analgesics. They contact with toxicology and indicate observation for 24 hours. On arrival at the hospital the patient is conscious, oriented and in good general condition but presents great oedema in the distal forearm and painful hand on palpation. It does not present bleeding vesicles, nor focal points of bleeding in other locations. There are neither signs of local infection nor areas of necrosis. As observation begins, the patient presents with nausea and sweating. Tetanus vaccine, intravenous analgesia and antibiotic therapy are administered. Blood analysis showed mild leukocytosis (10,250 cells/mm³) and thrombocytopenia (60,000 cells/mm³) with normal blood count. Toxicology is again consulted and recommends the administration of venom antiserum.

Results We verified that the patient complies with indication of degree II poisoning: local oedema that extends through the bitten limb with/without systemic symptoms (vomiting, diarrhoea and low blood pressure). Antiserum is administered after premedication with antihistamine and corticoid after 5 hours of bite. At 2 hours of administration, it presents great improvement with decrease of oedema and absence of pain. The next morning, the oedema has improved with respect to his arrival in the Emergency Department. The analysis continues to show leukocytosis (11,830 cells/mm³). In this situation the toxicology department is again contacted, which recommends repeating the dose of the antidote. After 24 hours of the bite a second dose is administered without incident and with decreased oedema. After 6 days of admission with good evolution the patient is discharged with analgesia and indication of elevation of the affected limb.

Conclusion Although snake antivenom is expressly indicated in European viper species (Vipera aspis, V. verus V. ammodytes), the most common species in our environment is the snouty viper (V latestei). The use of antivenom in this patient has effective and safe results.

References and/or Acknowledgements Technical datasheet: Viperfav.

No conflict of interest