Scalp psoriasis take a a while to treat. I understand that you have been to multiple dermatologists... but have you followed up?  In how many days did you change your dermatologist ? Why did you change dermatologists so soon? Also, eating and sleeping and exercise habits matter a lot. How are your habits? We will have to approach your problem holistically... since medications aren't working a bird's eye view is needed to pin point the reason for no improvement. Stress and psoriasis flares go hand in hand. Don't get frustrated please albeit it is. Scalp psoriasis can't be cured unfortunately.. it can be controlled for sure. It is difficult to treat or even suggest any cream or shampoo on such a forum ... Because a holistic approach is needed... thus only after follow ups can the dermatologist decide what works best for you.