Detection of Loxosceles venom in lesional hair shafts and skin: Application of a specific immunoassay to identify dermonecrotic arachnidism

Loxosceles spiders, of which the brown recluse is the best known, are indig enous to southcentral and southwestern regions of the United States. Loxosc eles spider envenomation frequently results in painful, centrally necrotic, erythematous skin lesions that evolve over 24 to 48 hours and may take sev eral weeks to completely heal. The diagnosis of loxoscelism is typically is based on the presence of the characteristic dermal lesion, because no defi nitive clinical diagnostic assay exists, and the spider is generally not av ailable for identification, We used a rapid Loxosceles-specific enzyme immu noassay to detect spider venom in a dermal biopsy and hairs plucked from a suspicious skin lesion on the lower extremity of a 9-year-old man. This rep ort indicates that in using a novel Loxosceles-specific immunoassay, venom can be detected in dermonecrotic skin and hair specimens for up to 4 days a fter envenomation. Copyright (C) 2000 by W.B, Saunders Company.