Is it a really light ... almost pink ... color? It sounds like what our vet called "Snow Nose". It's a loss of pigmentation and usually is nothing but looks a little odd. Our Toto has it down the middle of her nose and it gets darker in the summer. Our vet told us that we shouldn't be concerned about it unless other places i.e., lips, eyelids or any other black skin began to show loss of pigmentation. Sometimes that's a sign of some health problem going on but so far the only place Toto has is on her nose! Hope this helps.
Opps!! Kimberly & I must have posted at the same time ... or ... I'm old & slow!!