Brown recluse spider bites

Loxoscelism: Old obstacles, new directions

“…3,7,8,15,18,19,68,81,84,103 L O X O S C E L I S M Hogan, Barbaro & Winkel However, in the South American literature, necrosis at the envenomation site occurs in up to half of all patients. 58 This necrotic ulcer is the characteristic manifestation of Loxosceles envenomation and occurs in a smaller subset of those actually bitten, referred to as cutaneous loxoscelism.…”

“…The extent of dermal damage is correlated with diffusion of the venom itself. 6 Other factors that affect the lesion severity include the spider species, 59 spider sex and age, 60,61 the amount of tissue sphingomyelin 45 or adipose tissue at the envenomation site, 7 and genetic variance in individuals 62 and patient age. 4 The absence of a lesion 2 to 3 days after the bite usually indicates that necrosis will not develop.…”

“…This issue is further complicated by the fact that not all envenomations result in a dermonecrotic lesion. 7,22,37,[54][55][56] Wright et al 56 reported that only 12% of patients (n=111) brought the spider in for identification, with another 20% of patients seeing a spider around the time of the bite, leaving 68% with a presumptive diagnosis. In São Paulo, Brazil, more than 90% of the victims recall being bitten, although few patients bring the spider for identification.…”

“…Sporadic cases have been reported in a total of 17 additional states, including Massachusetts, Maine, and California, and may represent transported spiders from endemic areas. 1,3,5,7,8,[17][18][19][20][21][22][23] In Brazil, L gaucho, L laeta, and L intermedia are the prominent species. 24 L laeta is endemic to Chile 2 and Peru 25 but also has been found in Australia, 26 Finland, Russia, the Mediterranean, 18,23 and the United States.…”

“…The dark-colored violin-shaped marking on the dorsal aspect of the cephalothorax (hence the name ''fiddleback'') may not always be visible because of the variable color of the spider. 7 The first documented case of Loxosceles envenomation was in 1879, when a Tennessee man developed fever, jaundice, and hematuria after a spider bite. 8 More definitive and consistent data began to be published 50 years ago, when the first link between the Loxosceles spider bite and a necrotic skin lesion was first described in Chile, 9 followed by Brazil 10 and the United States.…”