Experimental brown spider bite in the guinea pig: Results of treatment with dapsone or hyperbaric oxygen

The brown recluse spider (Loxosceles reclusa) is a common inhabitant of the central United States. Loxoceles envenomation is a cause of significant medical problems, causing a necrotic skin lesion that often becomes a problem wound. Treatment of the skin lesion is controversial, with no current widely accepted therapy. The effects of treatment with hyperbaric oxygen or dapsone on brown spider bites were studied using guinea pigs. Progression and healing of experimental brown spider bites were measured in animals treated or pretreated with dapsone or hyperbaric oxygen and in controls. There was a significant decrease in lesion size in animals pretreated with hyperbaric oxygen at days 3,5, and 6 as compared to dapsone-pretreated animals or untreated controls. However, there were no differences noted between groups when treatment was begun 36 h after envenomation. There was a nonsignificant increase (p = 0.12) noted in myeloperoxidase levels from lesions of animals pretreated with hyperbaric oxygen. No other differences in levels of catalase, glutathione, or superoxide dismutase activity were noted between treatment groups. These results suggest that hyperbaric oxygen may have potential in the treatment of brown spider bites; however, further study is necessary to prove its efficacy.