Hello doc. i have a white patch area on my thumb and it's kind of iching.

Hard to tell..: It is hard to tell without seeing it, so, I recommend you see a physician so they can look at. That being said, itchy white patch makes me think of either fungal rash or psoriasis. A fungal rash would be treated with clotrimazole or other OTC antifungal. Psoriasis would be less likely, as you'd probably already have a history of it, but it would be treated by topical steroids. Show it to your doc.