It may just be due to moisture trapped under the band, especially if you are washing your hands more now that it’s cold and flu season. I’ve had this happen a couple of times, and I’ve been wearing my engagement ring for 10+ years and my wedding ring for >8. They’re platinum, so are hypoallergenic, and I’m fine with them the rest of the time, so I couldn’t figure out what was going on. If I am very careful to take them off after I wash my hands and really dry my hands totally, it will clear up pretty soon. The first time I had it happen, it was really bad (peeled to the point that it was raw and bled), and that time it took a while to clear up.
Also clean them with some jewelry cleaner or a little bit of ammonia or Windex in water to make sure there isn’t something else on them that might be irritating you. Make sure you rinse them really well and totally let them dry before putting back on.