Vascular surgeon. Thats the best place to start.
Wound care. If it is long standing non healing ulcer, see a wound care specialist or if short duration see your own physician..
See vein specialist. Leg ulcers are often caused by chronic venous insufficiency which is a problem that causes to much pressure to be in the veins near the skin. A venous specialist can diagnose and treat this condition. Our cure rate with venous ulcers is 97%. If it is arterial in nature you will be referred to an arterial specialist.
ID specialist- Several possible diagnoses can be given to a "small ulcer" on the leg, with the correct one most likely to be made quickly by an infectious diseases specialist. This specialist will be able to ask key questions that can determine if the ulcer is due to an infection (e.g. Leishmaniasis, syphilis), vascular insufficiency, trauma, diabetes, or other non-infectious cause.