Two successive necrotic lesions secondary to presumed loxosceles envenomation

Abstract

Brown recluse spider (Loxosceles reclusa) envenomations with subsequent necrotic skin lesions occur infrequently, and systemic loxoscelism is rarer still. We report a case of 2 successive developing necrotic lesions, each on adjacent medial aspects of the legs, secondary to presumed Loxosceles envenomation. A 31-year-old man with no significant past medical history presented to the emergency department with 2, large, necrotic lesions, 1 on each medial thigh. They had progressed over the course of 1 month from small blisters to large necrotic lesions with eschar. He underwent surgical debridement without skin grafting with no further complications. Bites from recluse spiders that progress to necrosis usually present as single lesions. The differential diagnoses for a necrotic skin lesion is large. The presence of more than 1 lesion argues against Loxosceles envenomation; however, in the absence of underlying infection, systemic diseases, immunodeficiency, or malignancy, the diagnosis must be considered if the case presents in an endemic area. Brown recluse spiders rarely bite multiple times, thus confounding the diagnosis of an already nonspecific clinical finding.