Brown recluse spider envenomation of the eyelid: an animal model.

The authors developed a rabbit model of the brown recluse (BR) spider envenomation of the human eyelid. The spider bite causes cutaneous necrosis and systemic toxicity in human eyelids, possibly leading to disseminated intravascular coagulation, hemolysis, and death. The treatment has been controversial. The animal model evaluated the effects of single- and combined-agent therapy in four phases: venom dose response, time course, therapeutic effectiveness (steroid vs. dapsone vs. antivenom), and optimal therapy (steroid and dapsone; steroid and antivenom; and dapsone and antivenom combination groups). The combination dapsone and antivenom treatment group was the optimal animal regimen, although not completely effective in eliminating microscopic necrosis. The authors also report dramatic clinical improvement in human inflammatory response with dapsone therapy and recommend immediate dapsone therapy combined with specific BR venom, if available, in humans.