North American loxoscelism caused by the bite of the Loxosceles reclusus, the brown recluse spider, can produce a gangrenous slough at the site of envenomation and a severe systemic reaction. In 16 cases the local reaction included pain, bleb formation, erythema, ecchymosis, necrosis ending in an eschar, and ulceration. The systemic reactions may include fever, nausea, malaise, hemolysis, and thrombocytopenia. Two deaths have been reported in small children. This spider is indigenous throughout the South Central US.