Q: My son was bitten by a rattlesnake on his calf and it looks terrible. Will there be any long-term side effects?
A: Thank you for your question! Snake bites are something we see at least once a month in the hospital, and often the ones that come in are suspected rattlesnake bites. It is good that people are quick to try to identify whether it could possibly be a rattlesnake or not. The antivenin, called CroFab, is available in most emergency rooms now, and quick administration of it is essential to minimize effects of the poison. The child is typically admitted to the hospital for this treatment. If the child receives medical attention quickly, outcomes are very good and there are typically no long-term effects.
Rattlesnake venom has two neurotoxins, both of which can lead to the severe effect of muscle paralysis. However, the amount of venom in most bites is fairly small and symptoms are mostly local to the bite site. Acute symptoms include severe pain and swelling around the bite site, bleeding from the bite site and local tissue bruising and destruction. There can also be involuntary quivering of muscles or muscle fibers around the bite site. This can all occur in minutes and progress rapidly within hours. The effects of the venom can progress from local to systemic as the venom which was originally only in the subcutaneous tissue makes its way into the victim’s bloodstream. Systemic symptoms include mouth and tongue swelling which can make it difficult to breath and bleeding from the mouth, or vomiting up blood. Some may also experience diarrhea, profuse sweating, fever, confusion, anxiety, numbness and tingling especially around the mouth, weakness and trouble swallowing.
While it is true that rattlesnake bites can be deadly, the occurrence of this is very low, since antivenin is fortunately widely available. The use of antivenin is determined by a doctor’s grading of the envenomation (poisoning). Minimal envenomation manifests as swelling, pain and bruising near the bite, but no systemic signs such as fever, sweating, nausea, vomiting or bleeding. This situation does not require any antivenin, but the child should be monitored for at least 8 hours. In the meantime, pain medication should be given. Moderate Envenomation is the second level, and has local symptoms as well as some systemic symptoms such as vomiting, a slight increase in heartrate and a slight decrease in blood pressure. There should not be any significant bleeding. Severe envenomation will have more severe local and systemic symptoms. For example, the swelling may extend to include the entire limb. Pain will be severe. The child may show altered mental status,low blood pressure, bleeding from the nose and mouth. The affected limb should be immobilized, the child should be transported to the nearest health care facility (preferably by an ambulance) and immediate administration of antivenin is necessary. If these things are done, outcomes are very good.
If your child is bitten by a snake in your presence, there are things you can do to help, and things not to do as well. Try to note the time your child was bitten and any details about the snake. If possible, draw a circle around the affected area on your child’s skin. Do not give your child anything to eat or drink. Do not use a tourniquet. Do not suck out the poison. Do call your local Poison Help Hotline or an ambulance immediately.
Only 25 types of snakes in the United States are poisonous, or venomous. The most common ones are rattlesnakes, copperheads, water moccasins and coral snakes. Of these, New Mexico has rattlesnakes and coral snakes. The bites we see the most in the hospital usually occur when a child sticks their hand into a pile of something, or they accidentally step on a snake that they didn’t see.
Tips on how to avoid being bitten by a snake include:
• If it slithers on the ground, it is best to leave it alone
• Do not try to capture or handle a poisonous snake
• Walk in cleared areas where it is easy to see where you step or reach with your hands
• Wear gloves when using hands to move rocks or brush
• Use a walking stick to rustle shrubs to alert a snake to your presence
• Patch holes in your home that are more than one quarter of an inch wide
• Be careful when working in crawl spaces
• Program the Poison Help Hotline number into your cellphone 1-800-222-1222.
Anjali Subbaswamy is a Pediatric Intensive Care Physician at UNM. Please send your questions to her at ASubbaswamy@salud.unm.edu