Hi. I guess you need to be seen properly by a qualified dermatologist. Thick persisting scalp scaling may just not be simple dandruff. Also even simple dandruff can persist for years and resolve intermittently with treatment. I am not sure if home remedies work but people claim to apply yogurt, egg white, lemon juice on scalp for dandruff. I am not prescribing the same, nor do I claim and benefits or side effects with these home remedies. So be careful and take a call. Better you see a dermatologist and take regular treatment. Let me know if you need any further assistance. Good luck n take care