Envenomations: an overview of clinical toxinology for the primary care physician.

About 4,000 to 6,000 venomous snakebites occur each year in the United States. Although these envenomations (also known as envenomings) are rarely fatal, about 70 percent require antivenom therapy. Few evidence-based guidelines are available for the management of envenomation. Antivenom therapy is the cornerstone of management for hemorrhagic or coagulopathic envenomation from pit vipers (with or without paralytic features), and for paralytic envenomation from coral snakes. Early intubation and ventilation may be required after bites from pit vipers whose venoms contain presynaptic neurotoxins. Although relatively controversial, antivenom therapy seems to be effective for the management of severe envenomation from widow spiders. Conversely, little evidence supports any specific management strategy for necrotic envenomation from recluse spiders. Cytotoxic fish stings, cnidarian stings, and traumatic penetrative envenomation by stingrays are typically managed symptomatically. Private collection of nonnative venomous animals in the United States is another source of medical risk.