I have a burning and itchy scalp. my hair are healthy and clean. however my skin itch in specific areas for a few days and it's a bit painful. help!

Selenium shampoo: Try selsun blue shampoo 2-3 times/week if you are not allergic to selenium or sulfa.

Seb Derm or acne nec: It's difficult to diagnosis you without seeing you but 2 possibilities are seborrheic dermatitis or acne necrotic miliarisis. Both conditions are exacerbated by scratching. You may want to try washing with a medicated shampoo like head and shoulders but if doesn't improve, go see a dermatogist.