This lesion was produced by the bite of a brown recluse spider. The brown recluse is one of two common spiders in the United States considered venomous. (The other is the black widow.) However, the hobo spider, wolf spider, and jumping spider can also produce bites that require medical attention.
Update Date 11/4/2015
Updated by: Jesse Borke, MD, FACEP, FAAEM, Attending Physician at FDR Medical Services/Millard Fillmore Suburban Hospital, Buffalo, NY. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.