As Ratel suggested, I definitely consider seeing your doctor about it. However, I'm going to go along the same lines as they said, sitting and typing for a long period of time without breaks can cause irritation, kinda gives your hands/fingers/butt a weird feeling if you haven't gotten up and moved around much.
If it's getting real bad, try using a anti-itch cream, if it doesn't help maybe head to Urgent Care and find out if it could be something deeper than just irritation.