Suggest Treatment For Dark Skin Patches On The Legs

hi i have a question im an african american woman and within 3 months i have developed these dark skin patches on the back of my calf on my right leg and a dark skin patch around my ankle, it doesnt itch or cause pain but its ust really dark like bruises but they arent it just randomly appeared and im trying to figure out what it is so i can treat it and clear my legs, i thought it could be eczema but it doesnt itch...what could this be?