Recently 1 of my 2 goldfish has started losing pigmentation around his nose, head and base of his dorsal fin. I have checked ammonia, nitrate (not nitrite unfortunately) and Ph levels and all are within acceptable limits. I do a 30-35% water change every sunday. I have had him in this tank (40Gal) for nearly 2 years now. I feed him a combination of tetrafin flake for goldfish, the odd pea and king british dried bloodworms

I first spotted this anomaly about a month ago and just kept an eye on it initially. there was only a single patch on his nose then. in the last week this has "spread" considerably as you can see in the image. I have gone through the usual, check list and have added a treatment of Aquarium Treatment 10 (Methylene Blue) as I first thought this could be fungal or parasitic but couldn't see anything by eye.

Other than the obvious he seems to be fine, eats his food, fins fully open and without blood streaks, and generally active. The other goldfish does not and has not shown any of these signs.

Update - He has also just removed a couple of scales on an ornament playing with the other fish (but could he have rubbed against this on purpose?)

Hopefully someone will be able to help me out here, I have uploaded an image of wht he looks like today and what he looked like about 6 months ago

Is it sticking out?(the patches)

I don't think there is a problem.Maybe he's just going through color changing.
But if it's sticking out it might be infections.

looks like a colour change

No, no sticking out whatsoever. If its just a colour change by all means move this thread to the non critical section! thanks guys for a rapid response

This is almost definitley a colour change. Young fish often change colours. I'm betting your fish is fine.

And...