injuries poisoning
Spider Bites
Introduction
Almost all of the 40,000 species of spiders are venomous. However, the fangs of most species are too short or too fragile to penetrate the skin. Serious systemic reactions most frequently occur with bites from Brown spiders: Violin, fiddleback, brown recluse (Loxoscelesspecies) Widow spiders: Black widow (Latrodectusspecies), brown widow (L. geometricus) Brown spiders are present in the Midwest and south central US, not in the coastal and Canadian border states, except when imported through clothing or luggage. Black widow spiders are present throughout the US. Distribution of the brown widow recently spread from Florida to all of the Gulf Coast states. Several other venomous spider species (eg,Pamphobeteus,Cupiennius,Phoneutria) are not native to the US but may be imported on produce or other materials or through commercial trade in spiders as novelty pets. Spider bites cause<3 deaths/year in the US, usually in children. Only a few spider venoms have been studied in detail. Of greatest significance are those having Necrotizing venom components (in brown and some house spiders) Neurotoxic venom components (in widow spiders) Sphingomyelinase D is the protein component that seems to be responsible for most of the tissue destruction and hemolysis caused by brown spider envenomations. The most toxic component of widow spider venom seems to be a peptide, alpha-latrotoxin, that affects neuromuscular transmission. 