Skin-nontumor / Clinical dermatology
Brown recluse spider

Author: Mowafak Hamodat, M.D., MB.CH.B, MSc., FRCPC (see Authors page)

Revised: 1 June 2016, last major update July 2011

Copyright: (c) 2002-2016,, Inc.

PubMed Search: Brown recluse spider

Cite this page: Brown recluse spider. website. Accessed June 25th, 2017.
Definition / general
  • Bite causes extensive necrosis, hemorrhage, blistering and ulceration (Wikipedia)
  • A chronic pyodermal gangrenosum-like reaction has also been reported
  • Also called loxoscelism (genus of spider is Loxosceles), necrotizing arachnidism
Clinical features
  • Diagnosis can be made by swabbing the lesion and using a specific enzyme-linked immunosorbant assay (ELISA) to detect the venom
  • Controversial
Clinical images

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Brown recluse spider bites

Microscopic (histologic) description
  • Varies from neutrophilic vasculitis with hemorrhage to arterial wall necrosis to eschar covered ulceration and subcutaneous necrosis
  • Usually eosinophils in the inflammatory infiltrate