We are sorry to hear about the issue you are reporting. The skin irritation may be a result of build-up on the watch band and/or casing. You should discontinue wearing your watch until your skin has healed. Please review the following FAQ that provides important information regarding the wear and care of your Garmin watch: https://www.garmin.com/watch-fit-and-care/
If you feel that this issue warrants further discussion please reach out to Garmin Product Support via Garmin Support Center
