Suggest Remedy For Round Thick Skin Appearing On My Left Shoulder Blade

I have roundish thick skin on my left shoulder blade they came suddenly and have never went away they did itched a little when they first appeared but they havent spread or grown since they first appeared and it been years I am black so they do appear darker then surrounding areas of skin when palpating it feels like thick ridges of skin they no longer itch nor have they ever had or haveany kind of fluid or puss normally asassociated with a pimple I do not have herpes nor have I ever been told I ever did in fact I dont even nor have I ever had a cold sore I do however have type 2 diabetes which I do keep in check I have no other ailments or infections to note I have been with the same partner for over 23 years with 4 kids none of them have or have had anything like these but they do get a cold sore from time to time