Bites by venomous snakes result in a wide range of effects, from simple puncture wounds to life-threatening illness and death. The findings following a venomous snakebite can be misleading. A victim can have no initial significant symptoms, and then suddenly develop breathing difficulty and go into shock.
Signs and symptoms of snake poisoning can be broken into a few major categories:
- Local effects: Bites by vipers and some cobras (Naja and other genera) are painful and tender. They can be severely swollen and can bleed and blister. Some cobra venoms can also kill the tissue around the site of the bite.
- Bleeding: Bites by vipers and some Australian elapids can cause bleeding of internal organs such as the brain or bowels. A victim may bleed from the bite site or bleed spontaneously from the mouth or old wounds. Unchecked bleeding can cause shock or even death.
- Nervous system effects: Venom from elapids and sea snakes can affect the nervous system directly. Cobra (Naja and other genera) and mamba (Dendroaspis) venom can act particularly quickly by stopping the breathing muscles, resulting in death without treatment. Initially, victims may have vision problems, speaking and breathing trouble, and numbness.
- Muscle death: Venom from Russell's vipers (Daboia russellii), sea snakes, and some Australian elapids can directly cause muscle death in multiple areas of the body. The debris from dead muscle cells can clog the kidneys, which try to filter out the proteins. This can lead to kidney failure.
- Eyes: Spitting cobras and ringhals (cobralike snakes from Africa) can actually eject their venom quite accurately into the eyes of their victims, resulting in direct eye pain and damage.
When to Seek Medical Care
Any snakebite victim should go to a hospital emergency department unless the snake is positively identified as nonvenomous. Remember, misidentification of the snake species could be a fatal error.
Bites by nonvenomous species require good wound care. Victims should receive a tetanus booster if they have not had one within the last 5 years.
Exams and Tests
Diagnosis of snakebite is made based on the history of the event. Identification or description of the snake would be helpful because not all snakes are venomous, and because different kinds of antivenom exist for different species of snakes. In Australia, the doctor may use a kit to determine the specific type of snake. The doctor also looks for evidence of fang marks or local trauma in the area of the bite. Pain and swelling accompany many snakebites.
- The doctor treats breathing problems, shock, and/or immediately life-threatening injuries even before a full workup is complete.
- The wound needs to be examined and cleaned.
- The doctor will likely send blood and urine samples to the laboratory to look for evidence of bleeding, problems in the blood clotting system, kidney problems, or muscle death. These problems may not be initially apparent, but can have dire consequences if missed.
- The victim is monitored to look for worsening symptoms at the wound site, or worsening systemic symptoms in the breathing or cardiovascular systems.
- A rare complication in very swollen limbs is compartment syndrome. Limbs are divided into compartments of muscles, blood vessels, and nerves. Severe swelling can cut off the blood circulation to a compartment. When the circulation is cut off, the victim usually has severe pain and numbness. Later, the limb may get white and cold. If not treated in time, the limb may need to be amputated.