The irritated area is not my external skin, it is in my sinus cavity between my nose and the roof of my mouth. Please help. Thanks?

Need more info. Is this an area that feels irritated when you touch it? Do you know it is in the sinus because you've had this problem before? Does irritation cause pain? sneezing and itching? Initial thoughts would include an erosion such as ulcer or blister or maybe congestion from viral illness, allergic rhinitis, or chronic non-allergic rhinitis. Consider a virtual consult to discuss symptoms further.