Iam 20 Years Old And I Have White Patches On

Iam 20 years old and i have white patches on my face for the last 10years. Some dermatologist told me that it is a common disorder of skin called PITYRIASIS ALBA. I have visited many dermatologist but no improvement on my skin. Last time when i visited a dermatologist he prescripted me OXIDON PLUS CAPSULES and PHYSIOGEL. Months over but no inprovement on my skin. I have stopped using the capsule but iam still continuing with the gel that he recommended I have dandruff too.
My skin is very sensitive.
I get red buns when exposed to sun for long duration.
Iam very much worried for my skin. Please help me :'(