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Snakes in San Diego:
Potent, Powerful Venom Cause for Concern

UC San Diego Toxicologist Offers Summer Bite & Sting Advice

June 9, 2008

By Kim Edwards

For the second year in a row, UC San Diego Medical Center toxicologists are reporting unusually powerful snake bites and unusually extreme patient reactions to those bites.  Since January, several patients have suffered bites with severe symptoms, such as difficulty breathing, often after a bite from the Southern Pacific Rattlesnake.

“Our victims are showing symptoms of severe weakness, trouble breathing and low blood pressure this year,” said Richard F. Clark, M.D., director of the division of medical toxicology at the University of California, San Diego and medical director for the California Poison Control System (CPCS), San Diego Division, UC San Diego Medical Center.

Symptoms can include: extreme pain at the location of the bite, nausea, and sometimes diarrhea, followed by swelling in the mouth and throat, making it difficult to breathe.  Within minutes, the victim can get lightheaded, collapse and go into shock.  With some rattlesnake bites, no venom is injected into the wound, but because it is impossible to know if venom has or has not been injected, getting medical treatment quickly is important.

Clark emphasized that while San Diego County is seeing a rise in snake bite cases each year, the more alarming factor recently is the toxicity of the bite.  Toxin levels in rattler venom vary from year to year and season to season but – typically- venom is weaker in winter and stronger in summer because snakes are more active, fighting for food and for survival.

“We really don’t know why the venom is becoming increasingly potent.  Some speculate that with the modern world encroaching on nature it could be survival of the fittest.  Perhaps only the strongest survive,” said Clark.  “UC San Diego will be conducting clinical trials later this summer with a new antivenom for rattlesnake bites.”

The majority of the injuries are on hands, fingers and feet, and the most typical result is swelling and tissue damage that looks like blisters or frost bite.

“What exacerbates the problem is that most bite victims are bitten on their dominant hand,” Clark pointed out.  “They’re reaching down a hole, perhaps trying to move the snake or handle the snake in some way, and they do that with their dominant hand.  When a person’s hand or leg is bitten, any movement is extremely painful: swelling occurs and the patient can’t bend the fingers, sometimes for months after the incident.  It can really affect daily life.  The patient can’t sign a check, write a paper for school, or hold a coffee cup.”

What to Do?
Get to the emergency department or a nearby health care facility immediately if you are bitten by a snake.  Administration of antivenom is the most important treatment.  Traditional first aid treatments such as applying ice, using a tourniquet, or applying suction to the wound have little value and may cause more injury.

If the victim is in a remote area when bitten by a rattler, first immobilize the wounded area, especially for a hand or arm bite, then proceed slowly to a vehicle.  Moving slowly will keep the heart rate low and help prevent the venom from spreading.  If bitten on the leg or foot, it might be necessary to use that limb to get to the vehicle, unless someone can carry the victim.  If walking is necessary, it is very important to move slowly.  Drive to the nearest phone, call 911 and wait for assistance.  If there is no phone nearby, proceed to the nearest hospital.

Other Concerns:  Bee Stings
Yearly reminders about bee stings are always part of UCSD Medical Center and California Poison Control System’s public outreach.  Recently, Africanized bees have proven to be a larger player than in previous years.

“Africanized bees are more aggressive than other bees so we advise people to stay away from wild bee colonies,” added Clark.

Africanized bees like to move around.  They are often seen traveling together, coming out of a water main or a bird house or from under the eave of a home.  The main difference between these bees and others is that they respond to a threat with more bees.

What to Do?
If attacked, the person being threatened should run and seek shelter away from the swarm, in a car with the windows rolled up, a house, a building, or any place that is not exposed to the outside.

If someone is stung, and is allergic, get the victim to a healthcare provider immediately.  Even if the victim is not allergic or unsure, but receives multiple stings from the swarm, seek healthcare immediately to be on the safe side.

Black Widow Spiders
There are thousands of different kinds of spiders in the world and all of them have some amount of venom with varying degrees of potency.  Fortunately, most spiders are not dangerous to humans because their fangs are either too short or too fragile to penetrate human skin.

Severe muscle pain and cramps may develop in the first two hours, usually first felt in the back, shoulders, abdomen and thighs. Other symptoms include weakness, sweating, headache, anxiety, itching, nausea, vomiting, difficult breathing and increased blood pressure. Young children, the elderly and those with high blood pressure are at highest risk of developing severe symptoms from a black widow spider bite.

What to Do?
Getting medical help is very important, but keep in mind, black widow bites are rarely if ever fatal.  Analgesics are the most important therapies for the pain associated with most black widow bites, but black widow antivenom is available at many emergency departments and can be effective in treating the most severe bites.

Within the next few months, UCSD Medical Center toxicologists will be starting a study with a new antivenom specifically developed to treat black widow spider bites.

Mosquitoes and Ticks
They are seemingly insignificant pests, but, oh, the damage they can bring.
Clark advises anyone who is going to be in wilderness areas to consider using a repellant containing “DEET.”  It is the best protection from biting insects.

“We want to remind campers, walkers, hikers, and the public in general, that San Diego does have occasional cases of West Nile virus and Lyme disease,” said Clark.  West Nile is spread through the mosquito’s bite and Lyme disease is carried by ticks.

What to Do?
If someone develops unusual symptoms such as fever and other flu-like symptoms after participating in wilderness activities, seek a healthcare provider immediately.

Sting Rays
The San Diego division of the California Poison Control System receives many calls from beachgoers who report being stung by venomous marine animals such as jellyfish, scorpion fish or stingrays.  If this occurs, the stinger should be removed and the wound washed with soap and water.  Clark said hot water has proven to be very effective in decreasing or eliminating the pain caused by string ray venom.

What to Do?
Clark recommends placing the affected area in water that is as hot as the sting victim can tolerate without burning the skin.  Using this therapy, the victim should feel better within 30 minutes.  If not, see a healthcare provider immediately.

If redness, drainage or swellings appear, there is likely an infection.  It is important to see a healthcare provider for treatment if an infection develops.The California Poison Control System (CPCS) is available at 1-800-222-1222, 24 hours a day, seven days a week for immediate expert help and information in case of poison exposure.


Media Contact: Kim Edwards, 619-543-6163

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