Symptoms and Management of Painful Progressive Swelling in Eswatini Snakebite Patients: A Prospective Observational Study

In Eswatini, bites from snakes with cytotoxic venoms inflict substantial morbidity on humans through blistering, swelling, and tissue necrosis. Despite its widespread use, there is little evidence regarding the efficacy of antivenom in preventing snakebite-induced tissue damage. We conducted a prospective observational study in nine hospitals in Eswatini to describe and quantify symptoms of local tissue toxicity. Our secondary aim was to examine the use of antivenom. Data from 125 snakebite patients with extensive or rapidly progressive swelling were analyzed. The median increase in circumference of envenomed limbs was 12%. Necrosis developed in 31 (25%) patients, primarily in distal extremities. Seventy patients (56%) received South African Institute for Medical Research (SAIMR) Polyvalent antivenom (South African Vaccine producers, Johannesburg South Africa), which was administered for indications related to local tissue damage. Upon hospital presentation, patients treated with antivenom exhibited slightly more severe swelling. Ten out of 11 patients with necrosis upon admission received antivenom. At least seven patients developed necrosis after admission despite previous antivenom therapy. In this nonrandomized observational study, no relationship was observed between the rate at which swelling receded and antivenom treatment. Adverse reactions to antivenom occurred in 49% of patients. Although our analysis has its limitations, it emphasizes the compelling need for research into the indications for and outcomes of antivenom treatment for local tissue damage.