Brown Recluse Spider Bite--or Something Else?

A previously healthy 40-year-old man complains of worsening lower-extremity discomfort. He noticed the discomfort several days earlier on awakening and thought that he had been bitten by a spider. The lesion, initially a small pustule, has enlarged into an open wound.

Does this look like a spider bite to you?

(Case and photograph courtesy of David Effron, MD.)

Click on photo to enlarge. For further details about the case, please click here.