• Distinguishing whether the patient has been bitten and envenomed, bitten but not envenomed, or bitten by a nonvenomous snake is critical prior to starting treatments
• Treatments may not only cause discomfort but may also produce serious side effects
• Bite by a venomous snake results in envenomation in only 50-70% of cases
• Degree of envenomation depends on the size of the snake and the duration of contact
• Include rattlesnakes, copperhead, and cottonmouth
• Can be distinguished from nonvenomous snakes by a round mouth and a pit between the eyes and the nares on each side
• Have retractable canaliculated fangs that can rapidly spring into biting position and deliver venom
• The large venom glands also give the head a triangular or diamond shape
• Have vertically oriented elliptiform irises
• Most deliver a primarily hemotoxic venom
• Hemotoxic effects are mediated by proteolytic enzymes, peptides, and metalloproteins that cause local tissue destruction directly and by intimal injury to blood vessels, followed by thrombosis and necrosis
• Activation of the coagulation cascade can occur at multiple points, resulting in net anticoagulation
• Have small mouths, short teeth, and deliver secreted venom into prey through created lacerations
• Bite lacks the characteristic fang marks of bites by pit vipers, sometimes making it hard to detect
• Body coloration pattern is red bands immediately adjacent to yellow bands
• Coral snake venom is primarily neurotoxic
• Neurotoxic venom can cause dysphagia, dysphonia, diplopia, headache, weakness, and respiratory distress
• Most snakebites in the United States are from nonvenomous snakes
• Nonpoisonous snakes such as the red milk snake and the scarlet king snake mimic the bright red, yellow, and black coloration of the coral snake
-True coral snakes have red bands immediately adjacent to yellow bands
-The mimics have black bands immediately adjacent to the red bands, thus the mnemonic: "Red on black, venom lack; red on yellow, kill a fellow"
• Puncture marks, local ecchymosis and discoloration, vesicles and bullae, and rapid appearance of swelling and edema at the injured area
• Pain of the bite can be quite severe
• Additional signs of hypotension, diaphoresis, nausea, weakness, and faintness are common
• Perioral or peripheral paresthesias, taste changes, and fasciculations
• Signs suggestive of neurotoxic envenomation include dysphagia, dysphonia, diplopia, headache, weakness, and respiratory distress
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