Medical References

Diseases & Conditions

Women's Health

Mental Health

Men's Health

Medical Web Links

Vitamin Shop

MOL Site Map

Sites

Attention, chocolate lovers: You may not be able to help yourselves. Swiss and British scientists have linked the widespread love of chocolate to a chemical "signature" that may be programmed into our metabolic systems.
Read more health news

Snakebite

Overview, Causes, & Risk Factors

A snakebite occurs when a snake uses its fangs to bite a person. Some snakes inject venom into the person through the fangs.

What are the causes and risks of the injury?

Many species of venomous snakes can bite and poison humans. These include pit vipers, such as rattlesnakes, copperheads, cottonmouths, or water moccasins. They also include tropical snakes, such as cobras, mambas, and coral snakes.

Symptoms & Signs

What are the signs and symptoms of the injury?

Signs and symptoms of a snakebite can vary, depending on the type of snake, the amount of venom injected, and the part of the body that is bitten. Symptoms at the site of the bite may include:

blood from the wound

pain

puncture wounds from fangs

swelling

tissue death, or necrosis

If the venom spreads to other body organs, additional symptoms may include:

blurred vision

diarrhea

dizziness

excessive sweating

fainting

loss of muscle coordination

nausea and vomiting

rapid heartbeat

seizures

weakness

Diagnosis & Tests

How is the injury recognized?

Snakebites are generally self-diagnosed. Usually, there will be two fang marks. However, one fang mark is possible.

Toxins from snakebite can cause significant problems with heart rate, blood pressure, and pain. Even when a snake is not poisonous, bacteria in its mouth can cause a serious infection when a person is bitten. Emergency medical care for all snakebites is crucial.

Pit vipers can deliver hemotoxins. These poisons work with other toxins to break down blood vessels and tissue. That causes tissue in the area surrounding the bite to die.

Many snakes from tropical areas and coral snakes have a poison called a neurotoxin. It interferes with the nerve impulses to the muscles. Bites from these snakes can be more dangerous and deadly than those from pit vipers. Emergency medical treatment is needed immediately.

Prevention & Expectations

What can be done to prevent the injury?

Being alert and prepared in areas where snakes are common is the best way to prevent snakebite. Protective measures to prevent a snakebite include:

Avoid situations in which a pet snake might be able to escape.

Be aware that it is hard to identify a poisonous snake just by looking at it.

Don't pick up or handle a snake without proper training.

Keep hands and feet out of any areas that cannot be seen.

Knock down high grass with a stick before walking through it.

Step onto logs and then across them, rather than over them.

Walk with a stick in front of the body, tapping on the ground to encourage snakes to move away.

Wear boots and pants to protect legs and feet.

Wear the proper gear when handling a pet snake.

Treatment & Monitoring

What are the treatments for the injury?

Antivenins are neutral antibodies used to counter poison from snakebites. These medicines are very expensive. It is always wise, if possible, to call ahead to the emergency department to ensure that antivenin is available.

Antibiotics, such as ceftriaxone, are often given for a few weeks when a person is bitten by a nonpoisonous snake. A DT booster shot may be given to protect the individual from Clostridium tetani\ bacteria. ',CAPTION,'Tetanus');" onmouseout="return nd();">tetanus organisms introduced into the wound.

When a snakebite occurs, these first-aid steps should be followed.

The victim should be kept calm. The site of the bite should be kept below the level of the heart. Movement should be limited. This helps keep poisons from circulating quickly in the blood.

Do not wash or rub the area around the bite.

Any constricting items, such as rings, should be removed.

Cover the area with a clean, dry pad.

If elastic bandages are available, wrap them firmly around the area. Start wrapping at the point furthest from the heart and wrap toward the heart.

The victim should be watched closely to make sure he or she is breathing.

If the snake is dead, it should be taken to the emergency department so that it can be identified.

The victim may show signs of shock, such as rapid breathing or loss of consciousness. In this case, the helper should lay the victim flat and raise the feet about 12 inches above the level of the head. The victim should be covered with a blanket. The emergency medical system should be contacted immediately.

There are several things to avoid when treating someone for snakebite.

Cuts should not be made in the skin near the bite.

No attempt should be make to suck venom out of the bite.

A tourniquet, or tight cord, should not be applied near the wound.

The victim should not be given anything to eat or drink.

What are the side effects of the treatments?

Antivenin and antibiotics may cause allergic reactions. Antivenin may also cause serum sickness, an immune system problem that causes joint pain and interferes with kidney function.

What happens after treatment for the injury?

People given antivenin usually recover fairly quickly. However, any tissue destroyed before antivenin was administered must heal. This can take weeks or months. If a large area was affected, skin grafts and other types of surgery may be needed.

People given antibiotics after a bite from a nonpoisonous snake usually recover well. Any new or worsening symptoms should be reported to the healthcare provider.

Attribution

Author:Adam Brochert, MD
Date Written:
Editor:Crist, Gayle P., MS, BA
Edit Date:06/12/01
Reviewer:Gail Hendrickson, RN, BS
Date Reviewed:06/07/01