Medical Aspects of Spider Bites

Abstract

Spiders have been incriminated as causes of human suffering for centuries, but few species worldwide cause medically significant envenomation. Widow spiders (Latrodectus spp.) occur worldwide and cause latrodectism, which is characterized by pain (local and generalized) associated with nonspecific systemic effects, diaphoresis, and less commonly other autonomic and neurological effects. Recluse spiders (Loxosceles spp.) are distributed mostly through the tropical and subtropical Western Hemisphere and can cause severe skin lesions and rarely systemic effects; most bites are unremarkable. Highly dangerous spiders in South America (armed spiders) and Australia (funnel-web spiders) cause rare but severe envenomation requiring medical intervention and sometimes antivenom. Most other spiders involved in verified bites cause minor, transient effects. Many spiders blamed for causing medical mischief have been elevated to medical significance via circumstantial evidence, poor reporting, and repetitive citation in the literature; several species have been shown to be harmless with more stringent scientific evidence involving verified bites in humans.

First study on lipid dynamics during the female reproductive cycle ofPolybetes pythagoricus(Araneae: Sparassidae)

“…In addition, certain species 48 of arachnids are a hazard to human health because of the harmful effect that their venom can 49 cause (Vetter and Isbister 2008), in some instances to the extent of causing fatality (Pezzi et …”

Chemical Control of Spiders and Scorpions in Urban Areas

“…A spider bite often inspires dread and is associated with a good deal of mythology resulting from the media attention that is given to the rare cases of fatalities [7,8]. There is usually an extremely low degree of tolerance among people of spiders in dwellings, even of those that do not pose any risk to human health or are not very aggressive.…”

“…), the venom may have evolved for defense against mammals www.intechopen.com (indicated by immediate painful bite due to venom components or to mechanical damage inflicted by large fangs). However, in recluse spiders, an initially painless bite at fang penetration with effects only manifesting hours later must be perceived as a mere evolutionary vagary of venom chemistry that such toxic components have effects on humans [8]. Most other spiders involved in bites that have been verified only have minor, transient effects.…”

“…Several species of tarantulas have urticating hairs that can cause some health problems [5,7,8,9]. Many spiders which have been blamed for causing medical ailments, have been elevated to medical significance as a result of circumstantial evidence, poor reporting, and repetitive citation in the literature; several species have been shown to be harmless when alleged bites in humans have been subjected to more stringent scientific evidence [7,8]. Spiders are not the only organisms that spin webs but the importance and various ways that spiders make use of webs has no parallel in any other group of animals [2].…”

“…Of the venomous spiders which are found in the urban environment, only Loxosceles species do not secrete a dragline. The spiders that spin orbicular webs are not included in the species that are confirmed to be of risk to human health [8]. Spiders can have two or three small claws, called tarsal claws, at the extreme ends of their legs ( Figure 1).…”