Most ulcers have more than one etiology. Ulcers of any primary origin such as ischemic, venous, or neurotropic ultimately get infected as well. Though the dominant disease process must be treated first, the superimposed infections require treatment also.

This is a misnomer because these ulcers are noninfected and are an important cause of non-healing ulcers of the leg. Ulcers of pyoderma gangrenosum may be associated with inflammatory bowel disease, inflammatory arthropathy, or myeloproliferative disorders [3]. Half of these ulcers are associated with chronic disease and the remainder are idiopathic. Lesions of the lower limb start as painful pustules which progress to necrosis and ulceration. These ulcers may be single or multiple with raised purple serpiginous undermined borders. Besides antibiotics, immunosuppressive therapy forms the mainstay of treatment.

Chronic ulceration due to atypical mycobacteria is a rare but important cause of non-healing leg ulcers. The organisms implicated are Mycobacterium ulcerans, Mycobacterium marinum, and Mycobacterium chelonae. The ulcers may start as a subcutaneous nodule and later transform into an undermined ulcer with an areola. The diagnosis is established by polymerase chain reaction-based identification of the organism. Treatment is with oral clarithromycin and topical silver sulfadiazine with hyperthermia [4]. The therapy needs to be continued for several months, and additional antibiotics may be required for secondary bacterial infection.