For years no matter what I have done any time I scratch my scalp I get white gunk under my nail. It's not dandruff I presume cause it's only when I scratch my scalp. I'm a curly so even tho I have tried harsh shampoos in the past....I now wash with very gentle shampoos and only a few times a week. But it really doesn't matter what I do. It's always there! It's gross. Anyone know what it could be? Thanks!