Evaluation of Allergic Reactions Following Intravenous Infusion of Polyvalent Antivenom in Snakebite Patients

Antivenom is a gold-standard treatment for snakebite envenoming. However, adverse reactions to snake antivenom are common in many parts.

The aim of this study was to evaluate the allergic reactions following intravenous administration of antivenom sera.

This was retrospective study conducted on snakebites patients referred to the Rahimi Hospital in Khorramabad. The files of these patients were accessed for demographic data, snakebite-related data, treatment provided, clinical presentation and allergic reaction status as a result of antivenom treatment.

141 cases were investigated, including 73.8% male and 26.2% female patients. The mean age of the patients was 38.1±17.1 years. Age group 30-39 years accounted for the highest number of snakebite cases (24.1%). A majority of victims (89.4%) were from rural areas. Most of the patients (51.8%) were bitten in the spring and highest number of snakebite were reported in May (39.1%). The most common site of snakebite was lower extremities (50.4%) and upper extremities (44.7%). Among clinical feature of snakebite, pain was the most prevalent in 135 cases (95.7%) followed by swelling (83.7%). The mean antivenom vials used were 6.5±3.7 vials. Allergic reactions occurred in 6 patients (4.26%); reactions were mild in 5 patients and severe in 1 patient. The commonest presentation was maculopapular rash (1.4%) and the least common were headache (0.71%), nausea (0.71%), fever (0.71) and hypotension (0.71%).

Snakebite is one of the significant life-threatening environmental events. Immediate antivenom treatment can reduce mortality however, patients should be carefully monitored for adverse allergic reactions.