Medical / Travel

Poisonous Snake and Other Bite Emergencies

In the wilderness the identification of reptiles, the diagnosis, and the treatment of their bites is an emergency.

On average, there are approximately 110,000 annual deaths worldwide from snake bites. About 90% of all bites are due to the intentional handling of snakes and 50% of these victims are drunk according to the Merck Manual. Other reptile bites, resulting in a fatality, are extremely rare. In prospective, mosquito related deaths worldwide is approximately 725,000 according to the WHO and NIH.

There are very few venomous lizard species in the world and even fewer fatalities. An interesting fact is that when they bite they keep on chewing and must have their jaws cut off to release the grip. It’s not a pretty picture is it? Crocodiles and alligators do not produce venom but puncture deeply introducing pockets of bacteria at high risk for infection.

Plan ahead:

  • Don’t feed iguanas!
  • Know what medical services are available i.e. nearby hospitals, doctors, and even zoos (many have antivenom or quick access to emergency services).
  • Particularly, if headed into the wilderness, take time to learn about native animals, reptiles, and flora. It can be fun and interesting e.g. Colombia has more native species of flora than any other country with over 130,000. At the very least, know what poisonous snakes and flora in the area look like.
  • Have a region specific first aid kit and maps of the area.


Snake Bite:

Immediate action:

  • When bitten, get out of danger. Many snakes do not expel all of their venom on the first strike. Fortunately even poisonous snakes often bite dry without injecting venom.
  • Try to remember the reptile’s color, shape, and size. Pit vipers have broad triangular heads, slit-like eyes, and fat bodies. All are poisonous.
  • BEWARE: The North American coral snake has a cigar shaped head and yellow and red bands touching each other. The similar scarlet king snake has red and black bands touching. The latter is non-poisonous. Remember: Red Against Yellow Killed A Fellow. All well and good unless you go to South America. The South American version of the coral snake has bands opposite the North American coral snake i.e. bands like the benign scarlet king snake.
  • Remain calm. Never try to capture the snake for identification. It has happened. Any unnecessary exertion increases the heart rate and the spread of venom.
  • Try to keep the bite area immobilized and below the heart if possible. A sling may help as most bites are on the upper extremities.
  • Do not try to stop blood flow and venom spread with a tourniquet, ACE wrap, or similar.
  • Remove jewelry and tight, binding items anticipating swelling.
  • Do not cut the wound or try to suck out venom as it doesn’t help and adds to the risk of infection.
  • Do not leave someone who has been bitten as symptoms can progress rapidly and there is the possibility of shock (covered elsewhere.)
  • Ice and heat on the wound will not help.

Symptoms: Symptoms are many depending on the type of snake e.g. a coral snake has venom that primarily targets the nervous system. Pit viper’s venom attacks blood cells and organs. Other variables depend on the amount of venom injected, the overall health of the individual bitten, and many other things. In general, they include:

  • Swelling around the site that progresses. Usually within an hour.
  • Lowering of blood pressure (hypotension), and passing out (syncope) or dizziness upon standing.
  • Excessive bleeding from the site. This is a sign of worsening and that the venom is causing coagulation problems.
  • Anaphylaxis and shock.
  • In the worst case, there is the potential for every organ in the body to be damaged leading to death.
  • Coral snake venom, as noted above, causes neurologic symptoms such as difficulty swallowing, difficulty breathing, double vision, weakness, and in the worst case, death.


  • If you are not the victim, closely observe changes in breathing and heart rate, increased bleeding, and progression of swelling. Keep the victim warm. If available, mark edema progression with a pen or marker along with the time. All of these things help medical personnel establish the severity.
  • You may have to support the airway if the victim goes into shock or respiratory failure.
  • Antivenom is used in serious cases. It is relatively snake specific due to the chemical makeup of various venoms. Some antivenoms are derived similarly to our vaccines. Small amounts of venom are injected into animals whose immune system produces antibodies to counteract the venom. Blood is withdrawn, purified, and inspected for human use. The point, if you have allergies to anything, including vaccines, let it be known to the first responders and doctors.

Other reptiles:

  • Treatment is symptomatic with repeated wound cleansing, cutting away dead tissue, and anti-biotics. Consult medical personnel if there is an increase redness or swelling, red streaking up the extremity, pus, or elevated temperature. (see treatment of non-poisonous bites)
  • There is no antivenom for lizard bites.
  • To leave you with an interesting fact, when poisonous lizards bite they keep on hanging on and chewing. They must have their jaws cut off to release the grip. It’s not a pretty picture is it?

For more see: My World: A Nasty Bite



One thought on “Poisonous Snake and Other Bite Emergencies

  1. Pingback: My World: A Nasty Bite | International Travel Advisor

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