THERAPY OF BROWN SPIDER ENVENOMATION - A CONTROLLED TRIAL OF HYPERBARIC-OXYGEN, DAPSONE, AND CYPROHEPTADINE

Study objective: To determine whether hyperbaric oxygen (HBO), dapsone , or cyproheptadine decreases the severity of skin lesions resulting f rom experimental Loxosceles envenomation. Design: Randomized, blinded, controlled study. Setting: Animal care facility. Interventions: We us ed New Zealand white rabbits. All groups received 20 mug of pooled L d eserta venom intradermally. Our control group received 4 ml of a 5% et hanol solution by oral gavage every 12 hours for 4 days. The HBO group received hyperbaric oxygen at 2.5 ATA for 65 minutes every 12 hours f or 2 days, plus 5% ethanol solution for 4 days. The dapsone group rece ived dapsone 1.1 mg/kg in 5% ethanol by gavage every 12 hours for 4 da ys. The cyproheptadine group received cyproheptadine. 125 mg/kg in 5% ethanol by gavage every 12 hours for 4 days. Results: Total lesions si ze and ulcer size were followed for 10 days. The lesions were then exc ised, examined microscopically, and ranked by the severity of the hist opathology. The groups did not differ significantly with respect to le sion size, ulcer size, or histopathologic ranking. Conclusion: Given t he negative result in this study with adequate power to detect meaning ful treatment benefits, we cannot recommend hyperbaric oxygen, dapsone , or cyproheptadine in the treatment of Loxosceles envenomation.