Spiders take blame for wound too often

They are called the villains of venom -- and blamed for countless emergency room visits each year.

 

Do Georgia's most-feared spiders -- the brown recluse and black widow -- deserve such a sinister title?

Perhaps not, according to veterinary entomologist Nancy Hinkle, of the University of Georgia Extension Service in Athens.

When Dr. Hinkle moved to Georgia from California in 2001, she was fascinated by the volume of apparent brown recluse spider bites reported across the state.

"Almost everybody I talked to knew someone who had been bitten," Dr. Hinkle said.

After studying to determine where the brown recluse lives, she said, she learned that most injuries attributed to spider bites aren't spider bites at all.

"In six years, we found 16 valid brown recluse spiders in the whole state of Georgia, and that's with everybody looking for them," she said. "We've had hundreds of people sending us spiders, and all the county extension offices were heavily involved."

All confirmed specimens were confined to about two dozen counties in northwest Georgia, she said. The majority of Georgia's 159 counties -- including the Augusta region -- have no brown recluse spiders.

"A few generations ago, admittedly, every medical school in the country held that if it was a dermonecrotic (flesh-eating) wound, it was a brown recluse spider bite," Dr. Hinkle said. "It's just now we're getting to the point where we realize other conditions produce these wounds, and there are about a dozen different causes."

Doctors who diagnose a spider bite often do so without evidence, such as the spider itself.

"Every ER doctor has probably diagnosed a brown recluse bite, but essentially it is impossible because the brown recluse has never occurred in a vast majority of the counties," she said.

Hartmut Gross, an emergency medicine physician at Medical College of Georgia Hospital, has seen his share of injuries that people believe are spider bites. In most cases, they aren't.

"I have a lot of people who come in and say they have a spider bite, but they never saw anything bite them," Dr. Gross said. "People think if they have a boil or abscess -- something itching, red or swollen -- then it must have been a spider that came up and attacked them."

The reality, however, is that it is almost certainly a staph infection.

Although another venomous spider -- the black widow -- is plentiful in Augusta, the brown recluse doesn't live in this region, he said.

"I have been looking for one for my collection for nearly two decades," Dr. Gross said. "Despite promises and people collecting all kinds of other critters patients have encountered and bring in with them, a brown recluse has yet to be among them."

Reach Rob Pavey at (706) 868-1222, ext. 119, or rob.pavey@augustachronicle.com.

THE STUDY

Clemson University, the Medical University of South Carolina and the University of California, in a joint study, evaluated data collected on spider-bite diagnoses in 1990 and again in 2004 in South Carolina.

The researchers found that doctors across South Carolina diagnosed 479 brown recluse bites in 1990 and 738 in 2004. Since 1953, though, only 44 brown recluse spiders have been found, all of them in six Upstate counties.

The conclusion, reported in an October 2007 bulletin from the American Board of Family Medicine, was that there were far more diagnosed bites than there are brown recluse spiders in the state, and most of the reports occurred in areas where there are no brown recluses.


THE REAL CULPRIT

Although countless Georgians head to emergency rooms each year with boils, abscesses and other wounds attributed to the brown recluse spider's flesh-rotting venom, the primary culprit is something much simpler, and much more common, according to veterinary entomologist Nancy Hinkle, of the University of Georgia Extension Service in Athens.

Methicillin-resistant staphylococcus aureus, an infection that can produce wounds similar to spider bites, is a fairly common occurrence in crowded environments, such as athletic programs, jails and even day-care centers.

"Typically, what people say are spider bites are skin infections," said Dr. Hartmut Gross, an emergency medicine physician at Medical College of Georgia Hospital. "Sometimes tissue damage from infections can cause similar wounds and that misconception is still there with the public."

A wound with MRSA tends to spread quickly and often has a fiery redness. It is exquisitely tender --just to look at it almost hurts. Boils can require incision, drainage and additional antibiotics to heal.


DETERMINING THE DIFFERENCE

A MRSA wound often cannot be diagnosed until a culture is taken, and many physicians do not routinely culture wounds. Nowadays, most skin infections are treated presumptively for MRSA using antibiotics. Cultures are expensive, and results take several days as the lab has to wait for something to grow enough to identify it (usually about 48 hours).

To tell the difference, the patient's history is important. That includes knowing the timing, whether the patient saw a spider in a brown recluse endemic area, and knowing the early and later presentations of the wounds.


DON'T TRY THIS AT HOME, KIDS

There are some old texts that suggest cutting out the dead area. Doing so doesn't work and can seriously damage underlying blood vessels and nerves. Some people have tried running an electric current through the wound. That doesn't work, either, and might cause an electrical burn to the skin and make things much worse.


WHAT TO DO

For true brown recluse spider bites, there's little that doctors can do except local wound care. Some physicians try prescribing various medicines, including cholchicine, dapsone, nitroglycerine and hyperbaric oxygen. The medications and therapies are aimed at trying to improve blood flow to the area, deliver more oxygen and slow down white blood cell migration into the wound. Keeping the wound as clean as possible without causing further harm and trying to prevent infection are your best bets.


FOR SKIN INFECTIONS

If you think you have a skin infection, applying mild heat (heating pad on "low," warm compresses or warm water bottle, 20 minutes on/20 minutes off) will bring more blood to the area.

An abscess might come to a head and easily break open, but vigorous "mashing" is discouraged, because the pressure can injure and weaken surrounding tissue.

You can try this for a day or two, but if it isn't getting better, you develop a fever or you see red streaks extending from the wound toward the heart, the infection has gotten out of hand. You have done all you can do, and it is time to go see a physician -- immediately.

If your primary doctor can see you promptly, fine. If not, go to an emergency room, because you will need antibiotics, possibly even intravenous antibiotics, and a short stay in the hospital.

-- Rob Pavey, staff writer