IMO, it's more common for white/light colored dogs across the board. Many Maltese, Westies, Bichons, yellow Labs, Golden Retrievers, etc. have skin issues. I do think genetics and breeding plays a big role though.
I have no idea, but I am owned by a cream standard who is almost five years old and he has no skin issues, allegries or sensetivities...knock on wood. I know nothing about his breeding and lineage, as I adopted him from a couple when he was 12 weeks old and had no papers. I assume he is back yard bred.
Its the same reason light skinned humans burn easily in the sun
I see a lot of white/light colored dogs who are more prone to skin irritations from the sun and bugs. My mothers white and grizzle Shih Tzu has fleas allergies and my high white Pit Bull has severe flea allergies.
In clipped breeds some white/light dogs are more prone to clipper burn but once the skin has been allowed to "tan" it gets better.
Now having said that the other colors can have just as many issues with skin. Like I have come across a few black Poodles who have dry itchy skin.