Envenoming: Consequences and Management

Abstract

Abstract Some snakes, arthropods and aquatic invertebrates can inject venom into prey or enemies by biting or stinging. Envenoming is a neglected occupational/environmental disease of the rural tropics, preventable by wearing proper footwear, using a light after dark and not sleeping unprotected on the ground. Treatment involves specific antivenom, supporting vital functions and surgical debridement of necrotic wounds. Snake bites: Local effects include swelling, blistering and necrosis. Life‐threatening systemic effects are shock, hemostatic disturbances, descending flaccid paralysis, rhabdomyolysis, intravascular haemolysis and acute renal failure. Arthropods: Hypersensitization to bee, wasp and ant venoms is a common cause of anaphylaxis. Mass attacks can also kill. Scorpion stings are intensely painful and may cause autonomic storm, particularly lethal in children. Spiders' bites are necrotic or neurotoxic. Marine stingers: Fish, jellyfish, coral, cone shell and sea urchin stings can be painful and dangerous. Immersion of the stung part in hot (not scalding) water relieves pain. Key concepts Animal venoms and venom apparatus have evolved to immobilize and digest the animal's prey, to facilitate haematophagy and for defence. Knowledge of the venomous fauna of a particular locality, use of protective clothing and avoidance of sleeping on open ground reduce the risk of envenoming. Antivenom, purified immunoglobulin from animals and hyperimmunized with specific venoms, is the only antidote to envenoming. Animal venoms may have tissue damaging local effects leading to permanent dysfunction and, by targeting physiological receptors, can cause haemostatic disturbances, shock, paralysis and autonomic nervous system overactivity. Snakebite is a neglected occupational and environmental disease of agricultural workers and children. The greatest risk after neurotoxic snakebite is the development of respiratory muscle paralysis before the victim can be delivered to medical care; the only known method for delaying this catastrophe is pressure immobilization. Bee, wasp and ant stings more often kill by anaphylaxis in hypersensitized people than by direct effects of their venoms.