It's tricky isn't it? You go to the docs following the general advice of the ABCD of moles and then they say it's okay....is it you or them?

You say it's on your back? How clear are you seeing the change? It's not easy to see this yourself or is a partner family member agreeing with you? Don't own these concerns alone as it's good to talk.

All I would say is a GP is not trained is skin to the level of a dermatologist. If you saw a specialist then I guess all you can do is get a couple of opinions, maybe from another dermatologist.

A dermo may opt to remove eventually but there may not be a need to, but then all the time they say no you won't feel comfortable. It's tricky and I am in a similar position. It's your health and your body but you do feel you have to trust them because they do this for a living.

My only advice is that if you are well and truly worried beyond the health anxiety as in, you are absolutely sure there is change and it is causing you to be unhappy, then try and contact your GP and request a referral. Also push that their judgement is being made without a reference point i.e. they are not taking images so how can they compare?

If you can afford it, maybe opt for a private assessment with a specialist - just make sure they are working with hospitals and not just a beauty type place. 

I have been using an app called SkinVision as well. They offer advice from real people (at a small cost) and are actually recommended by health professionals too. But you can use the app to record moles too to track changes.