Brown recluse spider envenomation

Barrett SM, Romine-Jenkins M, and Campbell JP (1989) Passive hemagglutination inhibition test for diagnosis of Brown Recluse spider bite envenomation. Annals of Emergency Medicine 18 441. 

Phylum Arthropoda is the largest phylum in the animal kingdom. Most of the species are nontoxic. However, Class Arachnida contains spiders. Arach-nidism means envenomation from a spider. Most spiders are venomous however, the black widow, brown recluse, and hobo spiders are responsible for a significant number of toxicity events in humans, so these will be discussed in more detail. 

Envenomation occurs subcutaneously due to the small biting apparatus of the spider. The Brown Recluse Loxosceles reclusa) spider, as its name implies, is found in secluded areas. Bites occur most frequently to the hands and arms while reaching into woodpiles or other well-protected areas. 

The bite of the Brown Recluse is usually painless and often goes unnoticed initially. The spider is seldom seen. Therefore, most patients do not seek treatment until a necrotic lesion develops. Within several hours of envenomation, local symptoms of redness and pain occur. Within 24 h, a reddish to violet colored blister becomes surrounded by a... 

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