DD has had it since birth (now 16 weeks). We tried olive oil on it for weeks but it seemed to be making it worse - kind of seemed to build up and make it thicker even though we were brushing it regularly. So then we've been using Dentinox cradle cap shampoo for about two weeks and that has dried it up and made her head flaky, but it seems to make her itch, and even though her nails are really short she manages to scratch at it until it bleeds.
Poor thing, her head looks horrible, really sore and dry with red scratches all over it.
DS used to have it but he had loads of hair so it wasn't noticeable and Dentinox cleared his up quite quickly.