Skin problem. Siddha medicines instead?

Suffering from psoriasis in the scalp, behind ears and on both legs below joints. Took allopathic medicines for almost 5 years with no better results. Have been undergoing homeopathic treatment for almost 6 years. Scaling reduced little bit but did not help with cure or reducing patches or itching. I have been very patient for years but it is very disappointing to see I am not able to get cured even after taking regular and proper treatment for these many years. Can some one please suggest if Siddha medicines are effective and can I expect complete cure or not ?? My homeopathy doctor says for some people it remains for life time but I want a second opinion on that. Diet wise I am a pure vegetarian. Could you please help if I should stop homeopathy and look for Siddha medicines instead ??