Until recently the black widow was considered the only spider in the United States dangerous to man. In 1955, physicians in Missouri and Arkansas began treating persons suffering from the bite of the brown recluse spider, whose poison caused serious damage to the skin at the site of the puncture and often produced a severe systemic reaction sometimes fatal to young children.

The spider is approximately 5/16 inch in length, dark brown to fawn, with long legs. A violin-shaped spot on the upper side of the cephalothorax (head portion) is the only noticeable identification giving rise to another common name—fiddleback spider. It is also known as brown spider, or brown house spider.

Little has been published on its life history, but it has been reported from Kansas, Illinois, the Gulf Coast, and from Tennessee to Oklahoma. It is extending its territory westward and has recently been reported from southeastern New Mexico and southern California. People are contributing to the rapid geographical spread of this species by unknowingly carrying it across state lines in their luggage. The brown recluse spider, according to Paul N. Morgan, research microbiologist at the Little Rock, Arkansas, Veterans Administration Hospital, “constitutes a hazard to the health of man, perhaps greater than the Black Widow.”

Where found

It is found in open fields and rocky bluffs but thrives particularly well in outhouses, garages, dark closets, storerooms, and in piles of sacking or old clothing. Its web is large and irregular.

The brown recluse bite

Because of the spider’s nocturnal and retiring habits few people are bitten, in spite of a large spider population. According to an article in the August, 1963 Journal of the Arkansas Medical Society, “there may be mild transitory stinging at the time of the bite, but there is little associated early pain. The patient may be completely unaware he has been bitten, and the spider is seldom seen. Only after 2 to 8 hours does pain, varying from mild to severe, begin. After several days an ulcer may form at the site of the bite. The venom appears to contain a spreading factor resulting in a spread of the necrosis or tissue destruction. In some instances, the ulcer may be so large that skin grafting is required, but the graft may take poorly or not at all. “The bite may also produce serious systemic symptoms including fever, chills, weakness, vomiting, joint pain, and a spotty skin eruption, all occurring within 24-48 hours after the venom injection.”

Treatment for bite of the brown recluse spider

Physicians at the University of Arkansas Medical Center, Little Rock, prefer the prompt administration of corticosteroids, stating, “Large doses given early may completely prevent the gangrenous response as well as the systemic reaction. The dosage schedule which we have found most effective is: 80 mg. of methylprednisolone (Deep-Medrol) intramuscularly immediately followed by one or two additional doses of same amount at 24-48 hour intervals. Subsequently, step wise decrease to 40, 20, 10 mg., every 24-48 hours, depending on the patient’s response, is carried out.”

Dr. Herbert L Stahnke, Director of the Arizona Poisonous Animals Research Laboratory, reports that an antivenin has been prepared in South America to control both the local and general symptoms from the bite of a closely related species of Loxosceles. He states, “locally there seems to be a favorable response to hydroxyzine, 100 mg. four times a day. I would say that cryotherapy, as we recommend it, would prevent all symptoms. I would recommend that the site of the bite be packed in crushed ice for 6 to 8 hours, after which the patient should be kept warm to the point of perspiration with the ice pack continuing for a total of 24 hours. In other words, treated like a pit viper bite, but over a much shorter period of time.” Avoid narcotics (morphine, demerol, dilaudid, codeine, etc.) since they enhance the systemic effects.

Although the brown recluse has not yet been reported in Arizona, it may be expected at any time, according to Dr. Mont A. Cazier, professor of zoology at Arizona State University at Tempe. In the meantime, studies are being made of the several close relatives of Loxosceles reclusa known to be present in the state. Among these is L. unicolor, first collected near Littlefield and Virgin Narrows in 1932. Equally poisonous with reclusa is the similar L. laeta, also found in Arizona. Other members of the genus, L. deserta and L. arizonica, have been known to live in Arizona and elsewhere in the Southwest for more than three decades, but no studies have been made of their venom. Dr. Willis J. Gertsch, world famous authority on spiders, believes that there may be as many as 20 species of Loxosceles in the Southwest. Several reports by persons who have been bitten by spiders describe reactions similar to those caused by the bite of the brown recluse.

According to Dr. Findley E. Russell, toxicology researcher of the University of Southern California Medical School, the “venom” injected by the brown spider is not really a toxin but a complete chemical that inhibits the normal action of infection-fighting antibodies in the human anatomy.