My 8 wo DS's head stinks. It's a horrible sour smell. I kept thinking he'd thrown up some milk and I'd missed it and it had gone stale. I know cradle cap can cause this but he doesn't have any visible signs of flakiness or scaly skin. Could it still be cradle cap? Any tips on how to get rid of it? I miss the lovely newborn smell from his head when I cuddle him! 