While relatively rare even in regions where they’re endemic, a bite from a venomous snake constitutes a serious medical emergency. Depending on the species of snake, severity of envenomation, and size and health of the individual bitten, a bite from a venomous snake can result in disfigurement, permanent loss of function, amputation, or in some rare cases, death. It’s imperative anyone living in or visiting a region where venomous snakes live be capable of recognizing the symptoms of a venomous snake bite. While identification of the snake is one way to know, it’s sometimes unfeasible and usually dangerous to actively pursue identification of a snake that has bitten you. A reliable, safer way is to be on the lookout for the following warning signs.
Severe pain is one of the surest signs of envenomation. A bite from a venomous snake will be considerably more painful than the bite from a non-venomous snake of comparable size. Cyto, cardio, and hemotoxic venoms (produced by most species of rattlesnake, Cottonmouths, and Copperheads) differ markedly in chemistry and mechanism of action, but will all rapidly begin breaking down and digesting the tissue surrounding the bite. This results in excruciating pain and stiffness in the affected limb, while neurotoxic venom, produced by coral snakes and some species of rattlesnake, may not be immediately noticeable, but will eventually become agonizing as the venom hijacks the nervous system and overwhelms many of the channels that the body uses to signal pain.
While most venomous snakes endemic to the United States will cause rapid or immediate pain, certain species that produce neurotoxic venom may be asymptomatic for over twelve hours. As a rule, severe pain at any point within twenty-four hours of a snake bite should be treated as a potential envenomation requiring medical assistance.
Redness and Swelling
Within seconds of envenomation, the body will begin to respond. In a similar fashion to how it will respond to a mosquito bite or bee sting, the body will flood the site with histamines, causing redness and swelling. As the effect of the venom progresses, the swelling and redness will spread outwards from the site and may result in tight skin that’s warm to the touch, and stiff or immobile joints. The swelling of tissue is especially prominent and dangerous with cyto and hemotoxic venoms and may be severe and widespread enough to cause tissue death on its own by constricting an extremity’s blood vessels to the point the muscle is unable to receive oxygen and dies. Such an event is a medical emergency in and of itself, and may result in permanent loss of function in the limb or even amputation. Excessive redness and swelling can also be a sign of allergic reaction and impending anaphylactic shock, also a medical emergency in its own right.
Nausea And Vomiting
The body may react to a venomous snake bite, as it would in most exposures to toxic substances, by inducing nausea and vomiting. While snake venom is delivered via injection, the body’s defense mechanisms may respond in much the same way it does an ingested poison, futilely trying to encourage the rapid expulsion of the toxin by inducing vomiting, diarrhea, or other digestive distress. Neurotoxic venom may also directly cause dizziness and nausea as it disrupts the body’s system of balance. The individual may feel seasick or have the sensation of vertigo following an envenomation. While the symptoms may have a rapid onset following a bite, they may take many hours, or even a full day, to occur, especially when the snake in question is a species utilizing neurotoxic venom. Any instance of serious nausea or vomiting within twenty-four hours of a known or suspected snake bite should be treated as a potential envenomation, and a serious medical emergency requiring immediate professional care.
Following envenomation, the individual may experience tightness of the chest, labored breathing, or, in especially severe or advanced cases, respiratory arrest. Respiratory distress may, depending on the species of snake and the type of venom it produces, be a result of the damage or death of the muscles responsible for breathing, a lack of blood flow to the lungs, or specific or general muscular paralysis resulting from the disruption of the body’s motor pathways. Chest tightness and difficulty breathing can also be a sign of anaphylactic shock, a not uncommon (especially in the case of repeated envenomations) but potentially deadly response to snake venom. As in the other warning signs, symptoms may take seconds, minutes, or hours to arise, so any sign of breathing difficulty within twenty-four hours of a suspected snake bite should be treated as a serious emergency requiring medical care. The onset and escalation of respiratory distress may be rapid and catastrophic once symptoms appear, so prompt care at the first sign of breathing difficulty is especially important.
Disruptions In Vision
Blurred, tunnel, double, or outright loss of vision may occur following an envenomation. Disruptions in vision may result from rapid shifts in blood pressure, damage to the ocular blood vessels, increase in pressure inside the eye, and neurological disruption. In rare and serious cases, the damage to the eyes may be severe enough to cause permanent loss or impairment of vision. Depending on the underlying cause, onset may be rapid or take hours, with visual disruption resulting from neurotoxicity taking up to eight hours to appear. The onset of visual symptoms may be gradual, or may occur suddenly, and may or may not be accompanied by physical pain or discomfort in the eyes. Disruptions in vision occurring within a day of a suspected snake bite should be taken as a symptom of possible envenomation, and immediate medical help should be sought to minimize damage to the eyes and other systems of the body.