Hi, As you said you suffer from psoriasis from 13 years.... I would like to say few things about psoriasis. Psoriasis is a chronic relapsing and autoimmune disease. You may be having scaly plaques on various parts of the body,scaly lesions on the scalp. Exact cause is not known. Genetic tendency, autoimmunitity,stress,dry wheather...etc may be responsible for precipitation and exacerbation of psoriasis. You consult dermatologist for firm diagnosis and treatment. I usually recommend cap acitretin 10 mg twice a day along with methotraxate 15 mg weekly in three devided doses 12 hourly...for psoriasis.This may be taken for long time till good response. Blood tests may be done to monitor the treatment. For itching, you may take antihistaminics like levocetirizine. You may apply mild steroid cream or calcipotriol oint on the lesions on the psoriatic lesions. You may apply moisturiser to improve the skin texture. For scalp lesions, have tar based shampoo daily along with night application of steroid with salicylic acid lotion.You should avoid soap bath for few weeks..And you should be free of stress and worries as that might worsen psoriasis. You might get good result.I hope you got my answer. Thanks. Dr. Ilyas Patel MD