Snake eyes: Characterization of topical ocular exposures from rattlesnakes in Arizona.

Patients occasionally present with reports of ocular exposure to fluids from rattlesnakes, claiming or suspecting the substance to be venom. This study set out to evaluate and characterize reported cases of suspected venom-induced ophthalmia in humans. A retrospective review of rattlesnake exposures reported to the Arizona Poison and Drug Information Center over a 24-year period was conducted for ocular exposures.

Fashionably late: A characterization of late coagulopathies in rattlesnake envenomations between Fab and F(ab')2 antivenoms.

Background: Rattlesnake envenomation may lead to a multitude of clinical effects, including a late onset hemorrhage. Laboratory values such as platelets and fibrinogen are commonly used to assess the risk of developing a life-threatening bleed. To date, no specific threshold has been identified that links a lab value to the risk of bleeding.

Mohave Rattlesnake (Crotalus scutulatus) Identification Revisited.

Crotalus scutulatus (Mohave rattlesnake) is a clinically significant pit viper broadly distributed across much of the arid southwestern United States and mainland Mexico. Identification of C scutulatus is a concern among emergency medical service and emergency department personnel owing to its reputation for severe envenomations and difficulty in visually differentiating between C scutulatus and other species, primarily Crotalus atrox (western diamond-backed rattlesnake). We contrast distinctive characteristics of C scutulatus, C atrox, and 3 other sympatric species: Crotalus molossus, Crotalus ornatus, and Crotalus viridis (western and eastern black-tailed rattlesnakes and prairie rattlesnake, respectively).

When one phenotype is not enough: divergent evolutionary trajectories govern venom variation in a widespread rattlesnake species.

Understanding the origin and maintenance of phenotypic variation, particularly across a continuous spatial distribution, represents a key challenge in evolutionary biology. For this, animal venoms represent ideal study systems: they are complex, variable, yet easily quantifiable molecular phenotypes with a clear function. Rattlesnakes display tremendous variation in their venom composition, mostly through strongly dichotomous venom strategies, which may even coexist within a single species.

Interfang Distances of Rattlesnakes: Sexual, Interspecific, and Body Size-related Variation, and Implications for Snakebite Research and Management.

Objectives: Snakebite severity corresponds to size of snake because the amount of venom a snake injects is positively associated with snake size. Because fang marks are often present on snakebite patients, we tested whether the relationship between snake length and distance between fang puncture wounds can be generalized for rattlesnakes of genus Crotalus.

Methods: We measured 2 interfang distances from 79 rattlesnakes of both sexes, 5 species, and varying body length: 1) distance between fang bases in anesthetized snakes, and 2) distance between fang punctures in a membrane-covered beaker bitten defensively.

Recognizing dangerous snakes in the United States and Canada: a novel 3-step identification method.

The rapid and accurate recognition of dangerously venomous snakes following bites is crucial to making appropriate decisions regarding first aid, evacuation, and treatment. Past recommendations for identification of dangerous North American pit vipers have often required subjective determinations of head shape or relied on traits shared with some nondangerous species (elliptical pupils and undivided subcaudal scales). Heat-sensitive facial pits are diagnostic but require close examination of the dangerous head, and cephalic traits are useless when working with a decapitated carcass.

Pressure immobilization delays mortality and increases intracompartmental pressure after artificial intramuscular rattlesnake envenomation in a porcine model.

Study Objectives: We determine the effect of pressure immobilization on mortality and intracompartmental pressure after artificial intramuscular Crotalus atrox envenomation in a porcine model.

Methods: We prospectively studied 20 pigs using a randomized, controlled design. After anesthesia, C atrox venom (20 mg/kg) was injected with a 22-gauge needle 10 mm deep into the tibialis anterior muscle of the hind leg.

Mojave toxin in venom of Crotalus helleri (Southern Pacific Rattlesnake): molecular and geographic characterization.

Mojave toxin (MT) was detected in five of 25 Crotalus helleri (Southern Pacific rattlesnake) sampled using anti-MT antibodies and nucleotide sequence analysis. All of the venoms that were positive for MT were collected from Mt San Jacinto in Riverside Co., California.

Crotalidae polyvalent immune Fab (ovine) antivenom is efficacious for envenomations by Southern Pacific rattlesnakes (Crotalus helleri).

Study Objective: Southern Pacific rattlesnake (Crotalus helleri ) venom is not 1 of the 4 venoms used to produce Crotalidae polyvalent immune Fab (ovine) (CroFab; FabAV). There is currently no published clinical experience regarding the efficacy of this new antivenom for confirmed C helleri envenomation, and animal data suggest greatly diminished efficacy. We assessed the efficacy of FabAV for patients with confirmed C helleri envenomation.