Verified envenomations by crevice weaver spiders (genus Kukulcania): Bites are of minor expression but the spiders are commonly misidentified as medically important brown recluses (genus Loxosceles) in North America

Abstract

From southern North America, five verified bites by crevice weaver spiders, Kukulcania spp. (Filistatidae), are presented here, three of which are pediatric cases. Although the envenomation manifestations were of minimal expression, the salient aspect of this report is that Kukulcania spiders are frequently misidentified as brown recluse spiders (genus Loxosceles ) which are infamous for causing serious dermonecrosis and rarely, life-threatening systemic effects. Misidentification of this relatively harmless spider as a medically important recluse when presented to a physician in an envenomation episode could lead to unwarranted and overzealous treatment such as contraindicated debridement of the affected area.

A Brief Overview of the Toxic Sphingomyelinase Ds of Brown Recluse Spider Venom and Other Organisms and Simple Methods To Detect Production of Its Signature Cyclic Ceramide Phosphate

“…There have been occasional observations of apparent SMase D/PLDs in venoms of other spiders, such as Kukulcania hibernalis, based on cross-reactivity to an antigenic assay for L. reclusa venom (Aran-Sekul et al, 2018;Gomez et al, 2002). However, this is not thought to be a dangerous spider, and an analysis of case reports of five verified envenomations from Kukulcania spiders noted that all were with minor manifestations (Vetter, 2022). The reason SMase D/PLDs appear in other spiders is not clear, but might be for digestion of prey (Binford et al, 2009), as highlighted by a recent report of SMase D/PLD in Uloboridae spiders, which are the only spider family that has lost its venom glands secondarily during evolution (Valladao et al, 2023).…”