Balanitis xerotica obliterans is a chronic inflammation of the skin of the glans and foreskin, in some cases affecting the urethra.
A dermatologist is a doctor who specializes in diseases of the skin, hair, nails and mucous membranes.
The urologist is the doctor who specializes in the male and female urinary system and the male reproductive system.
Remember that for the proper selection of health professional that treats balanitis xerotica obliterans you must consider the nature, severity and symptoms you are presenting.