Indigo Swale, I was glad to see you inject (ouch) a little scientific knowledge into this discussion.
My house is full of brown recluses--they are the most common house spider around here (Missouri Ozarks). I don't know anyone personally who has had a necrotizing wound from a brown recluse, and my family has lived in this area forever.
Most doctors don't know squat about entomology, and they
misdiagnose necrotizing wounds as spider bites.
California, for example, has a very high number of reported brown recluse bites, and very very tiny number of actual verified brown recluse spiders, because THEY DON'T LIVE THERE.
From the University of California at Davis
Brown Recluse and Other Recluse Spider Management Guidelines--UC IPM (and a similar article from Florida
2004 - Bronson Urges Closer Consideration:
"There are fewer than
10 documented cases of the spider being collected in California, spanning more than 4 decades, typically in facilities that receive goods from out of state. Searching the immediate area yielded no additional brown recluses and therefore they were considered to be individual stowaways.
Undoubtedly, more brown recluses have been inadvertently brought into the state via commerce and the relocation of household belongings; however, amazingly few specimens have ever been collected. Never have any of these translocated spiders been able to establish a foothold and start a population in California.
Considering that there are millions of brown recluses cohabiting with people in the southcentral Midwest and brown recluse bites are only an occasional occurrence there, California does not have anywhere near sufficient populations of these spiders to be responsible for the number of cases or illnesses that are attributed to them.
MEDICAL MISDIAGNOSES
One reason for the great "awareness" of the recluse spiders throughout the United States is that necrotic wounds are misdiagnosed as "brown recluse bites." Although recluses can cause these wounds, the biological data involving the distribution of the spider indicate that most of these diagnoses are incorrect.
A world-renowned toxicology physician who worked at University of Southern California Medical Center estimates that most spider bites in California referred to him were actually the work of other arthropods and that 60% of "brown recluse spider bite" diagnoses came from areas where no
Loxosceles spiders were known to exist.
Nationwide, some "brown recluse bites" were subsequently correctly diagnosed as
Staphylococcus infection,
Streptococcus ("flesh-eating bacteria") infection, Lyme disease, herpes simplex, diabetic ulcer, or bites from bedbugs, mites, ticks, small wasps, biting flies, or other spiders.
In addition, in one case where the offending spider was killed in the act of biting, a Californian doctor misidentified the spider as a brown recluse even though the spider had eight eyes, stripes on the cephalothorax, a patterned abdomen, and spines on the legs.
In any event, 90% of all brown recluse bites in the Midwest heal without severe problems and millions of people have lived there for years without experiencing bites."