Sounds like a bad case of either scalp psoriasis or seborrheic dermatitis
leading to a skin condition called 'pityriasis amiantacea'. Here is how I treat this:
1. Tab Augmentin 625mg thrice a day for for 5-7 days, to control the pus if present.
2. Capsule Itraconazole 200 mg twice a day for 7 days. Thereafter on the first two days for three consecutive months.
3. Coal tar shampoo (Ionil-T) + 2% ketoconazole shampoo (Nizoral-AD) applied alternate day, left on the scalp for 5 minutes.
5. Soak the crusts in olive out overnight- put the oil liberally over the crust, sleep wearing a shower cap - gently tease out the crusts while showering. Repeat weekly if required. Otherwise on a daily basis avoid using any hair oil or greasy hair cream.
5. Fluocinolone lotion applied twice a day to the irritated skin for 14-21 days
Results are best when entire treatment regimen is followed. I would recommend seeing your doctor and discussing my recommendations with him/her, as most of the above are prescription drugs. Hope this helps.