Suggest Remedy For Skin Problem In Finger Knuckles

i have a problem with my finger knuckles ,they look dark in color and they are not painful nor itchy .this problem have been there for some time now and i have been trying to get reed of it but to no avail.when i consulted ones ,a certain doctor told me its eczema which is just like inheritance from one of my family members .so he gave me some tablets and certain creams but i have not seen any changes,the things keeps spreading everyday and may be it will soon cover the entire fingers.what is the best advice you can give me?