Can warfarin cause itchy skin even after being on it for years?

It is possible.: Itching is a possible side effect of warfarin and many other medications which can occur at any time after initiation of therapy.

Could be possible: Almost any medicine can cause almost any side effect, but itchy skin from warfarin would not be very likely--especially if you have been taking it for a long time. I would look into other possible causes first, like a change in soap, detergent, lotion, fabric softener, or other medicine, etc.