Rotting-Ear Case the Work of Deadly Brown Recluse Spider

March 13, 2012— -- The brown recluse spider got some bad press again this week.

Nikki Perez, a fashion merchandising student at Texas Christian University in Fort Worth, described how she lost part of an ear and nearly her eye sight to the venomous arachnid.

"It was terrifying," she told the British Daily Mail newspaper. "It was spreading all over my head."

Perez, 21, was stung at the Amarillo airport and was later hospitalized for five days in September. Her head swelled to twice its normal size and she needed a skin graft to rebuild the ear that had rotted from necrosis.

The Daily Mail sounded an alarm about a University of Kansas study by graduate student Erin Saupe, saying the "deadly" spider was "spreading ... to a town near you."

The study was published last year in the online journal PlosOne

The spider's habitat is limited to the Southeast and Midwest, stretching from Kansas east to the Appalachian states.

But Saupe of the university's Geology and Biodiversity Institute used computer modeling to predict how it's habitat might move north to states such as Wisconsin, Michigan, Pennsylvania and even New York, dependent on climatic suitability for the species.

Spiders are, after all, one of the top 10 phobias.

But Rick Vetter, the nation's foremost expert on the brown recluse spider -- loxosceles reclusa -- said such media reports use "scare tactics," and 90 percent of the time a bite causes nothing more than a red mark on the skin.

"These are distorted reports ... hyperbolic media crap," said Vetter, a research associate in the department of entomology at the University of California-Riverside.

A Kansas home, for instance, was infested with 2,055 brown recluse spiders for a period of 17 years and "not one" in the family of four was bitten, according to one of his studies, published in the Journal of Medical Entomology.

He said gnarly photos of Perez's injuries looked authentic and he had known a 9-year-old who had lost an ear from necrosis. But such cases are rare.

The spider's venom -- sphingomyelinase D -- induces red blood cell destruction. Symptoms can include pain at the site of the bite, itching, muscle and joint pain, as well as vomiting and fever.

"My crusade is to stop stupidity in the medical community," Vetter said.

When doctors blame a skin lesion on the brown recluse, they might overlook other more serious conditions such as methicillin-resistant staphylococcus aureus (MRSA), diabetes or even lymphoma.

In a 2005 article he co-wrote in the New England Journal of Medicine, Vetter cited 40 other conditions that can cause necrosis often misdiagnosed as a spider bite.

Vetter was so tired of doctors blaming the much-maligned spider, he started the Brown Recluse Challenge. Of 1,800 specimens sent to him, only 350 turned out to be the real deal. And all were from the Midwest.

A brown recluse bite can be life-threatening in 10 percent of the cases, but Vetter estimates there are only one or two deaths a year, typically in small children.