I Have Had A Rash Around My Mouth And Under

I have had a rash around my mouth and under my nose for a year. It comes and goes and I cant relate it to something specific, like the sun or foods, etc. I have noticed my eyelids swell and are tender from time to time especially when the rash is inflamed. I have been using a cream, triamcinolone acetonide, which only keeps the symptoms at bay. It never goes away.