Hi.., As you said you suffer from psoriasis from last 15 years.I would like to say few things about psoriasis... . Psoriasis is a chronic relapsing and autoimmune disease. There 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 only local treatment for psoriasis in pregnant and lactating women.For itching, you may take antihistamnics like levocetirizin...Avoid steroid ,as there may be severe flare up after stopping it. Roxithromycine is safe, you may take it if needed. 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. 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