Definitely, it is an allergic reaction. You might need to take an anti histamine. A better option is to see a physician who would likely ask you to take some skin ***** allergy tests, and would definitely be in a better position to prescribe a medication.
It could be a nerve on the top of your nose causing you to do this. If I were you, I would ask people not to touch my nose. If it concerns you, you should see a doctor.