Do brown recluse spider bites induce pyoderma gangrenosum?

Brown recluse spider bites are usually self-limited skin lesions that infrequently progress to bullae, ulceration, and scarring. We treated a patient with a documented brown recluse bite who had recurring lesions resembling pyoderma gangrenosum (PG) that persisted for months. Three other patients referred to Vanderbilt University because of probable brown recluse bite also had pyoderma for the first time after a suspected arthropod bite. The persistent and recurrent pyodermas in these four patients indicate that (1) brown recluse spider bites may not be self-limited but induce PG or PG-like lesions; (2) arthropod bites in general may induce PG in susceptible people; and (3) treatment of the PG-like lesions in these patients may be difficult.