Clinical Features and Antivenom Usage in Northern Cottonmouth (Agkistrodon piscivorus) Envenomations in Texas.

IntroductionCottonmouths, also known as water moccasins, are responsible for <10% of the ∼5000 snakebites reported to America's Poison Centers annually. Envenomations are characterized primarily by local findings. Gastrointestinal signs and hematologic abnormalities have been reported. There are currently 2 antivenoms that are approved by the Food and Drug Administration for the treatment of cottonmouth envenomations. The purpose of this study was to describe the clinical features and antivenom use in the treatment of Northern Cottonmouth envenomations in Texas that were reported to the North American Snakebite Registry.MethodsWe reviewed cottonmouth bites reported between January 1, 2013, and December 31, 2024. Data regarding the circumstances, patient demographics, clinical features, treatment, and outcomes were reviewed.ResultsSixty patients, with a mean patient age of 26 y, were included. Females accounted for 20 cases (33.3%). Lower extremity bites accounted for 35 cases (58.3%). Swelling was observed in 56 cases (93.3%). Emesis was reported in 10 cases (16.7%). Two patients (3.3%) experienced diarrhea. Hematologic laboratory abnormalities were present in 10 patients (16.7%). Antivenom was administered in 47 cases (78.3%), including 22 pediatric patients (84.6%). Three patients (6.4%) who received antivenom experienced minor acute hypersensitivity reactions.ConclusionsCottonmouth envenomations are characterized primarily by local tissue injury. Gastrointestinal signs and hematologic toxicity are observed less commonly. Antivenom is often administered for cottonmouth bites and is associated with a low incidence of acute hypersensitivity reactions. There is a trend toward treating pediatric patients more aggressively.