Hi. Thanks for posting your concern at HCM Scalp scaling and itching specially if it is present as well defined patches resistant to conventional treatments OR recurs rapidly could be because of Scalp psoriasis OR Severe Seborrheic dermatitis. The treatments that you mention are indicative of the same. Since it is a chronic problem you need to use medicated shampoos for control as well as to maintain the improvement. I usually ask my patients to use a tar+salicylic based shampoo daily OR alternate days. Together with this topical Steroid+salicylic acid lotions usually give marked improvement within 2-4 weeks, in my opinion. Once improvement is attained it is necessary to sustain that with the shampoo though you can decrease the frequency of shampoo to either alternate days OR twice weekly. In my opinion apart from topical steroids, Calcipotriol lotion (with or without steroid) also works effectively for scalp psoriasis and is safe for long term use. I would advice that you consult your dermatologist with all these points in mind. take care