Loxosceles and Loxoscelism: Biology, Venom, Envenomation, and Treatment

Abstract

Loxosceles spiders are not aggressive and have nocturnal habits. Accidents occur owing to the compression of the spiders against victims' body parts. The envenomation can progress to cutaneous necrosis at the bite site and, less frequently, to intravascular hemolysis. Loxosceles venom is has many components, among them phospholipase D, which is responsible for inducing dermonecrosis and complement-dependent hemolysis. The mechanism of action is very complex and multifactorial. Several treatments have been suggested for loxoscelism particularly antivenom, corticosteroids, and dapsone. As the cutaneous lesions of loxoscelism progress in a variety of forms and diagnosis is often relatively delayed, the assessment of treatment efficacy is compromised.