Has anyone ever heard of or seen a cat with symmetrical fur loss around the eyes and color change on the nose, muzzle, and butt? Patricia's face did not always look like this:
She also did not always have gray fur around her butt holes or black fur in the spay scar area.
Know about it, so the best suggestion I can have for you is this:
Have your baby examined by your regular vet and have him or her do one or more skin scrapings to get a basic idea of what this could or could not be and to rule out some possibilities. Then, depending on your vet's findings, you might want to get a referral to a dermatologist and possibly even to an internal medicine specialist.