Many diagnoses of brown recluse spider bites come from areas apparently
outside of the brown recluse’s habitat. Brown recluse spiders are found
mostly in the central and southern U.S., an area that includes Texas,
Arkansas, Missouri, Kentucky, Tennessee, parts of Illinois, Indiana,
and Georgia. Brown recluse spiders also inhabit the states bordering
the Gulf of Mexico.

Yet Vetter has fielded reports of brown recluse bites from
Wisconsin, New York, even Alaska and Canada. In virtually every case,
systematic searches in those places have turned up no brown recluse
spiders.

In one analysis, Vetter counted 188 reports of brown recluse
bites in three years in California, Oregon, Washington, and Colorado.
But only 15 brown recluse spiders have ever been found in those four
states. "These bite diagnoses are everywhere, and yet no one can find
the spider," Vetter said. "Show me the spider."

Even where brown recluses do live, people overestimate their
risk, Vetter said. In one recent case in Kansas, a family of four
collected more than 2,000 brown recluse spiders in their house during a
six-month period. The family found spiders on the paper towel rack,
crawling up the stairs, and lurking in piles of laundry. "There were
four people living in that house for six years," said Vetter, who wrote
about the case in the November issue of the Journal of Medical Entomology. "Guess how many bites? None."

Vetter and colleagues have recently embarked on a project to census
brown recluse spiders in northern Illinois and southern Iowa. Similar
studies elsewhere should provide doctors and the public a better
understanding of brown recluse spiders.

"These spiders are dangerous and they can cause nasty wounds," Vetter
said, "but the perception of the brown recluse as a serious health
threat is overstated."