Snakebites

This article provides an overview of the different families of venomous snakes and their characteristics, as well as the incidence and importance of snakebite globally. It also delves into the prevention of snakebite and the composition and pharmacology of snake venom. The article highlights the complexity and diversity of snake venoms and the variation in venom composition within a single species throughout its geographic range, at different seasons of the year, and ontogenically as the snake matures. It also notes that prevention is key in reducing the risk of snakebite, and that attempts to exterminate venomous snakes are futile and ecologically undesirable.Snakebite can cause a range of symptoms and clinical effects, depending on the type of snake and the dose and site of injection. Misguided traditional pre-hospital treatments can also result in swelling and ischemia of limbs, vomiting, and other side effects. The earliest symptom is usually pain, while local swelling may start within minutes. Envenoming by elapids can produce neurotoxic symptoms such as vomiting, headache, and difficulty speaking, while vipers can cause bleeding and clotting disturbances. Shock is most commonly the result of hypovolemia, vasodilatation, or direct action of venom on the myocardium. Snakebite can also cause generalized rhabdomyolysis and acute kidney injury, which can be the major cause of death in victims of sea snakes, some Australasian elapids, Russell's vipers, some Bothrops spp., and Cr. durissus terrificus. The ringhals and African and Asian spitting cobras can eject venom in a fine stream from the tips of their fangs for a distance of a few meters, causing venom ophthalmia with intense local pain, leukorrhea, blepharospasm, and palpebral edema.