How do you get rid of red, blotchy patch of skin under your nose?

Dermatitis. There is no way to tell what the causes of a patch of dermatitis is without seeing it. Therefore you must see a dermatologist to get this resolved. However, i can say that there are serious conditions in this area which need to be examined. These include such conditions as basal cell carcinoma, seborrheic dermatitis, rosacea, and many others.
Depends. It can be dermatitis which will respond a topical steroid such as hydrocortisone. If improvement is not significant a stronger strength may be necessary. See a dermatologist for proper evaluation if the 1 % does not work.