What Causes A Hard Boil Below The Bridge Of The Nose?

I have had a boil on the upper part of my nose. My eye doctor did not recognize it as such and there was no aggressive treatment. I did not know what it was until I searched online and saw the pictured and description. It is now a hard, small core and is sore if touched but has had only casually treated in relation to a scratched cornea of the eye above it. It is now a small, hard core dry scab that is sore to the touch. I finally have an appointment to a dermatologist in four weeks only becaused my primary doctor did not treat it. What should I do in the meantime? and is a dermatologist the right treatment specialty?