Randomly inside of lip (where bottom touches top) will sting, swell like a welt, and a red ring will form. started a few mos ago, along with dryness?

Allergist or ENT: This symptom may be recurrent angioedema which may or may not be an allergic reaction to something internal like a medication, or external like toothpaste, lipstick,etc. Since the reaction is always at the same site, maybe an otolaryngologist should examine the site first; otherwise a consultation with an allergist may be worthwhile.