Derm Dx: Pus blisters on the leg evolve into ulcers

A 56-year-old woman presents complaining of painful and foul-smelling crusted ulcers on her leg and thigh. The patient reported developing several “pus blisters” on her leg and thigh 10 days prior that had enlarged over the course of several days and subsequently developed a black crust.

The patient endorses mild to moderate pain, but denies fevers. Symptom review is ...