I think it is just a habit. I'd do a mark on paper sort of thing every time you do it to learn to quit doing it. I had an itchy scaly thing above my eyebrow once and went to the dermatologist who did a lot of tests to make sure it wasn't something serious, I had been working as chairman of a book sale at the library so it was probably just an allergy to the plastic on some old hardback books, or paper dust or something. . . anyway, we got to the end and I asked for a cream or something to make it stop itching and he said, "no, you have to quit scratching". I lost that battle and it only cost me $100

Touching the face is a pretty common habit:

How to Keep Your Hands Away from Your Face: 9 Steps