Hello and welcome to healthcaremagic.
I have gone through your query and I have understood it.
Psoriasis is an inflammatory skin disease characterised by well defined erythematous scaly plaques with silvery white or candle wax type of scaling. Chronic
plaque psoriasis is the most common type.
It commonly affects the scalp. Other sites that can be affected are arms, and legs, (specifically elbows and knees), palms and soles etc
For scalp psoriaisis, you could use a coal tar+
salicylic acid based shampoo, thrice weekly for 2-4 weeks.
Topical steroid+saicylic acid based lotion can be used for the thick scaly patches of psoriasis fr 2-4 weeks
Since steroids are usually avoided over long term therefore once the patches are significantly improved, you may switch to topical Vit D analogues e.g
Calcipotriol,
calcipotriene solution.
These are all prescription medicines, therefore I would suggest that you see a
dermatologist before trying them
Regards