I got stuff off the doctor a few years ago called Doublebase which I use for dry and itchy skin on my hands which I get in the colder months. I'm still using the same tub which was prescribed to me even though on the tub it says bb Sep. 2006. It still seems to work ok but is it a bad idea to use it or does it matter?
i would say get rid of it. It only takes another quick appointment and 7 quid later at the doctors to renew your cream. You dont want it to cause more distress to your itching and dry skin as you never know what ingredients are in the cream that go manky after a long time and 2 years is long enough.
doublebase is just a fancy easier absorbed vaseline. If you went to the pharmacist and asked for an emollient similar to it, its about 3 quid for a litre and does the same job. Superdrug have their own version, maybe you could chuck that out if you are concerned and get a cheaper version without the prescription.