Derm Dx: Ulcer on the index finger with painless red bumps on the forearm

An otherwise healthy Oklahoma man presents to his primary care provider with ulcers on his index finger and elbow, and painless red bumps on his forearm.

The rash was preceded by an abrasion from a rose thorn that the patient sustained while landscaping three weeks earlier, which occurred at the same site as the lesion on the index finger. The ...