By Buck Tilton
Reprinted from The Leader, Spring 2001, Vol. 16, No. 2
"I don't like spiders and snakes," goes the old Jim Stafford song, a sentiment echoed by multitudes of humans from Alabama to Zimbabwe. And there's plenty to not like. Of approximately 60,000 species within the class Arachnida, the eight-legged of the world, 30,000 are spiders. In some spider rich areas, experts estimate the count of individuals may run as high as 265,000 per acre, making spiders among the most numerous of all earth creatures. Scorpions, more arachnids, make up another 650 species of the class. And snakes slither into one of about 2,700 species of that scaly group known as reptiles.
At least some of the dislike for these animals arises from the fact that they bite, or sting (if they're scorpions), and it hurts. Dislike reaches fear-and-loathing proportions when you remember the pain may be followed by death. But what, truly, are the risks?
Bad news. Almost all spiders, worldwide, carry venom which can be injected through fangs that pierce their prey or enemies. On the plus side, only a few dozen species have a bite harmful to humans, either because they inject too little venom or their fangs cannot penetrate human skin. One of the most venomous, the black widow, common in the United States, bears the tag "cosmopolitan," a spider found around the globe. Only the shiny female of the species poses a threat, and she packs more danger in every drop of venom than any other creature in North America. The hourglass on her abdomen helps identify her. She has been found in every state but Alaska, privately secluding her web under logs and pieces of bark, in stone crevices, in trash heaps and outbuildings, deep in clumps of heavy vegetation. Rarely aggressive, she may be touchy during mating and egg-tending season.
Fortunately her drop of poison is tiny. You almost never feel the bite, although some victims have reported immediate sharp pain. There may be little or no redness and swelling at the site initially, but a small red bump may form later. Within 10-60 minutes symptoms begin to occur. Pain and anxiety become intense. Muscular cramping often spreads from the wound, settling in the abdomen and back. Burning or numbness characteristically disturb the victim's feet. Watch for headaches, nausea, vomiting, dizziness, heavy sweating-common reactions.
More "good fortune:" You might think you're going to die, but black widows kill very few humans each year, only two to four in the United States, and they are almost always the very young, the very old, or the very allergic. Keep the victim as calm as possible. That is your best first aid treatment. If you can find the bite site, wash it, and apply an antiseptic such as povidone-iodine. Cooling the injury, with ice if possible, with water or wet compresses if necessary, will reduce the pain. Cold also reduces circulation which slows down the spread of the venom.
Evacuation to a medical facility is a great idea, just in case complications arise. Most people will receive painkillers and eight to twelve hours of observation. Youngsters and oldsters may be admitted for 24 hours. Antivenin is available if needed.
Her name, black widow, is the stuff of nightmares and legends, but the most common serious spider bite in the United States is not from her venom. Instead, look for the secretive recluse (a.k.a., fiddleback, violin spider). Generally pale brown to reddish, and 9-14 mm in length, with long slender legs, they most often have the shape of a violin on the front portion of their body. The head of this "fiddle" points toward the tail of the spider. Unlike the black widow, both sexes of recluses are dangerous.
The recluse prefers the dark and dry places of the South and southern Midwest, but travels comfortably in the freight of trucks and trains, and probably can be found in all 50 states. They don't mind the company of humans, and set up housekeeping beneath furniture, within hanging curtains, and in the shadowed corners of closets. Their bite is more common indoors, but they live well-hidden beneath rocks, dead logs, and pieces of bark in forests all over America. They attack more readily in the warmer months, and curious children are their most frequent victims.
Like most spiders, their bite is often painless. Having relatively dull fangs, the serious wounds they inflict are usually on tender areas of the human anatomy. Within one to five hours, a painful red blister appears where the fangs did their damage. Watch for the development of a bluish circle around the blister, and a red, irritated circle beyond that. This is the characteristic "bull's-eye" lesion of the recluse. The victim may suffer chills, fever, a generalized weakness, and a diffuse rash.
Sometimes the lesion resolves harmlessly over the next week or two. Sometimes it spreads irregularly as an enzyme in the spider's venom destroys the cells of the victim's skin and subcutaneous fat. This ulcerous tissue heals slowly and leaves a lasting scar. In a few children, death has occurred from severe complications in their circulatory system. Without the spider as evidence, it is difficult to be sure what is causing the problem. Initially, there is little to be done other than calming the victim, and applying cold to the site of the bite for reduction of pain. Any "volcanic" skin ulcers should be seen by a physician as soon as possible. Antibiotic therapy usually cures the patient.
For information on wilderness medical training: certifications and courses, visit the WMI website.