The Brown Recluse spider is not particularly aggressive. Most people who get bitten have contacted the spider in clothing or shoes that have not been used for a period of time. They typically can be found on the floor or behind furniture in areas which are left undisturbed. Fatalities are rare, but bites are most dangerous to children, elderly, and those in poor physical condition.
This well known and misunderstood pest is famous for its mating rituals where the female kills and consumes the male after copulating. The male Black Widow spider is smaller and totally harmless to man. The female is easily identified by the red hourglass shape on the abdomen. Black Widow poison is 15 times more lehal than rattlesnake venom; however, less poison is actually injected in a bite, so far fewer people die from spider bites. Black Widows prefer dark, humid places like wood piles, basements, and crawlspaces. Modern pest control methods are very effective in controlling and preventing spider infestations.
Although our customers (and their doctors) may tell themselves a Brown Recluse, Black Widow, or other unknown spider, has bitten them, this is not always the case. Sometimes, explaining the lack of harmful spider populations to our customers is often met with skepticism because they often believe that the doctor knows more about local spiders than the licensed pest control operator.
In the experience of most pest control operators, the general public and the medical community are quick to determine that all kinds of dermatological eruptions are the result of spider bites when there is no proof whatsoever that a spider was involved in the incident.
Many medical conditions, especially bacterial infections, are under the so-called diagnosis of a "spider bite" yet having nothing to do with spiders. Several of these more serious cases are misdiagnosed as Brown Recluse spider bites. What is seen, under further inspection, is a multitude of conditions that can cause necrotic (or rotting flesh) wounds that can be mistaken for a Brown Recluse spider bite. Brown Recluse's aren't the only things that cause necrotic wounds. Other conditions should also be given creence when determining the causes of skin lesions.
Bacteria infections. This is probably one of the biggest causes of skin inflammations on the body. Any time there is a puncture of the skin, there is a chance of bacterial infection. One of the most common things to do after any type of bite or sting is to eventually scratch the area of irritation. If the skin is broken, a secondary bacterial infection may occur. The would may have been initiated by a bite or sting but the infection that follows is not from the venom or salivary glands of the insect but from our own "grubby" fingernails that can cause the infections. This is one of the biggest problems with real Brown Recluse spider bites, which are notoriously free of bacteria for the first few days but then get infected when the itching causes the patient to scratch. The ensuing would is then blamed completely on the spider's venom, which is incorrect.
Viral and fungal infections. Various forms of herpes have been misidentified as Brown Recluse spider bites, which are simply caused by viruses. There are fungal infections associated with plant material on rose thorns, pine seedlings, hay, sphagnum moss, etc., that via a break in the skin can leave a skin lesion. If someone tells you that they received a Brown Recluse bite while gardening (Brown Recluse spiders are not found in vegetation), sporotrichosis is a likely candidate.
Ticks and Lyme disease. A misdiagnosis with sever consequences is that Lyme disease sometimes can exhibit a bull's eye rash or a necrotic lesion, which are characteristic symptoms of a Brown Recluse bite. Bites of other ticks can leave wounds that can be mistaken for spider or recluse bites including a soft tick.
Other arthropods. Fleas, mites, ticks, bedbugs, and kissing bugs can also leave puncture wounds of the skin which are susceptible to infection or reaction to salivary fluids. Even our own common fire ant bites can cause a bacterial infection by scratching the infected area. One of the problems with blaming spiders is that the homeowner starts to overlook the actual cause of the wounds, which may continue unabated.
There are several possible problems we may encounter such as topical contaminants, Lymphoma and other cancer-like diseases, blood disorders, and underlying physiological diseases that can cause rotting flesh wounds. Some of these conditions have no known cause or can be something as simple as a bed sore.
It is important to remember that the pest management professional is not a doctor and only a doctor can make medical diagnosis.
With the aforementioned information at hand, we hope you can use this to help in determining if in fact a spider was to blame for the wound or something else altogether.
Portions of this information were taken from the PCT article written by Rick Vetter, a staff research associate, entomology dept. at the University of California, Riverside.
