Psoriasis requires special shampoos which contain tar and salysalic acid in proportions and freqency which depends on your severity. All shampoos only help the 1st line lotions, alone none of the shampoos help. All shampoos that will help you will significantly dry your skin so i wpuld advise applying coconut oil half an hour before shampoo, a conditioner after shampoo
Next Steps
consult a qualified dermat to initiate some treatment, shampoos alone will not help and only aggreviate dryness
Health Tips
if your main concern is only scalp, an online consuly may suffice. for a more widespread issue please visit a doctor in person. DO NOT LET UNQUALIFIED PEOPLE FOOL YOU WITH MAGIC OILS AND SIMILAR PRODUCTS.