What Could Cause Persistent Tightness In My Upper Lip For Two Weeks Without Other Symptoms Or Signs Of Allergy?

Hello, I ve been having some tightness in my upper lip for the past 2weeks.i haven t eaten anything different so I don t believe any allergic reaction.There s no itching,chapness,driness,redness or swelling.It just feels tight and not really numb.Please Advise.