Cradle cap and scratching

Tessa

Little man (6 mo on the 18th) is constantly raking his fingernails across his head. I know it isn't always necessarily intentional but I get a little worried that he's really going to hurt himself. I do my best to keep his nails trimmed but it's been difficult. I wonder if his cradle cap is uncomfortable but I've read that it usually isn't.

Any tips other than mittens?