Pyoderma gangrenosum are rare, large painful ulcers or sores of which the exact cause is unknown, however, they may be associated with the immune system.
A dermatologist is a doctor who specializes in diseases of the skin, hair, nails and mucous membranes.
Remember that for the proper selection of health professional that treats pyoderma gangrenosum you must consider the nature, severity and symptoms you are presenting.