Suggest Treatment For Psoriasis

I have psoriasis, leading to red scaly spots on my legs for the past 15 years. Strangely, this problem seems to be related with the problem of asthma. When I don't have asthma, these red marks become inflamed and prominent. Tried loads of creams but of no effect. Also, I have a lot of dandruff and no shampoo is helping. Can you please help me out/ let me know about a good dermatologist in South DElhi?