What Causes Folliculitis In Head And Face With Dandruff?

Hi doc, I am suffering from folliculitis in my head and face,and also I am having dandruff. I haven't seen folliculitis beyond the neck region till now. I have tried Nizoral 2%, but to not much effect. What should I do?? Pls suggest me a remedy. I think its now for 3 years that I am having this problem.