This patient has Pyoderma gangrenosum. It is not a common finding in real life but it is commonly seen in exams.

If one sees this in a patient, one must think of Underlying Inflammatory bowel disease. Patients with ulcerative colitis have a high incidence of this. It is related to the activity of the underlying disease - meaning thereby that if the colitis is in remission, this too improves.

Local steroid injections or systemic immunosuppressants may be used to treat it.

The lesions in diabetics are necrobiosis lipoidica. They look similar but are found on the shin and are shiny with dilated capillaries visible on them.