By Sharon Omahen
University of Georgia
A University of Georgia researcher says brown recluse spiders in Georgia are being wrongly blamed for wounds they don't cause.
"Most of the state of Georgia doesn't even have brown recluse spiders," said Nancy Hinkle, an entomologist with the UGA College of Agricultural and Environmental Sciences. "If the spiders in the state caused all the wounds that are reported as brown recluse bites, they would be some very busy spiders."
Since 2001, Hinkle has tracked verified findings of brown recluse spiders in Georgia. The study was prompted by Hinkle's arrival from California.
Not a Southerner
"When I first came to Georgia, I heard several people say they knew someone who'd seen or been seriously wounded by a recluse," she said. "I found that odd since the recluse is a Midwesterner, not a Southerner."
The brown recluse is mostly brown but has a darker, violin-shaped design where its legs attach. With its legs extended, it's only about the size of a quarter.
Hinkle has received hundreds of spider samples from Georgians all across the state. Rick Vetter from the University of California at Riverside identifies the samples. He is the world's expert on brown recluse spiders.
Two out of 25
Lisa Ames with the UGA CAES Homeowner Insect and Weed Diagnostic Laboratory in Griffin also collects spider samples submitted by homeowners and pest control companies. In 2003, 2004 and 2005 she received an average of 25 samples each year. Only two samples annually have been recluses.
In all, the UGA scientists have collected only 14 verified brown recluse spiders. And they have confirmed the spider in just 26 of Georgia’s 159 counties, mostly in the northwest.
"Another reason for doing this study is to help the medical community rule out brown recluse bites from portions of the state that don't have the spiders," Hinkle said. "A diagnosis of a brown recluse bite in Savannah is highly questionable.”
Most likely not spider bites
Hinkle hopes the study will educate Georgia's medical community and reduce the number of erroneous recluse bite cases. A mark on the skin that looks like a spider bite could be something much more serious.
She believes many assumed brown recluse bites could be methicillin-resistant Staphylococcus aureus.
MRSA is a type of staph infection that's resistant to antibiotics like penicillin, amoxicillin and oxacillin. MRSA causes mild skin infections which result in pimples or boils. But it can also cause more serious skin lesions or infect surgical wounds.
"Over the past five to 10 years, the number of MRSA cases has burgeoned," Hinkle said.
Wounds look similar
A MRSA infection can look like a brown recluse wound.
A brown recluse spider's bite often isn't the painful part of the experience. The spider's venom destroys the tissue at the bite site. Several hours later, a blister-like sore appears and grows. It can become as small as a pin to 8 inches across.
Almost all brown recluse bites heal nicely without medical intervention, Vetter said. And in spite of all the horror stories, only 3 percent require skin grafts.
Incorrectly diagnosing MRSA as a spider bite, and vice versa, can result in a patient getting the wrong therapy, Hinkle said.
"The required treatment for a brown recluse bite is totally different from the treatment needed for MRSA," she said. "Common antibiotics don't touch MRSA. And you obviously wouldn't need to spray insecticides when you aren't dealing with a spider problem."
Brown recluse spiders aren’t vicious and are not looking to bite people, Vetter said. A Kansas family collected more than 2,000 brown recluses from their home in six months.
"They've been living there for eight years and still have shown no evidence of a single bite," he said. "People tend to overreact and believe the worse."
The UGA brown recluse study will conclude this year. To participate by submitting a spider sample, go to www.ent.uga.edu and click on Spider ID Project at the bottom of the page.
(Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)