Why does my philtrum feel tingly and flaky?

Early cold sore?: I am very impressed you used the word "philtrum"--i have not used or heard of that word from anyone in a very long time. Anyhow, cold sore can come out on/at or near this area and can start out as tingly sensation. Because the nerve also controls the health of your skin, this "pending area" is affected and skin can dry out/die quicker, hence flaking. If worsening, consult doc. Good luck.