Since psoriasis is known to be a waxing and waning condition, it usually subsides with regular treatment. It is unusual for anyone to suffer extensive scalp psoriasis for a long time, especially if they seek medical help and use treatments as directed. Any medical regimen for psoriasis needs to be closely supervised by a dermatologist. Topical medications like corticosteriods are effective against scalp psoriasis. They are available in solutions, gels, creams, lotions and ointments. A two-week cycle of treatment is commonly recommended for strong steroids.
More on what is psoriasis and the genetic component of psoriasis