I'm sure you wanted to say psoriasis instead seryasis.
This is a chronic, life-long skin condition appearing in few differnt types.
Patients with psoriasis have an immune system that sends faulty signals, that results in very rapid growth of the skin cells.
This inherited defect in immune system, is often, triggered by external factors like stress and emotional trauma, skin injury, use of certain medications, and others.
Psoriasis can't be cured, but, its symptoms can be treated, or in other words that are periods free of symptoms and periods of flare-ups.
Different treatments can be used depending on severity of condition and their effectiveness (different drugs and combination of drugs are differently effective to people).
Usually, therapy is started with locally applied creams and ointments.