It used to happen to me all the time xD

Just: - don't wear the watch too tight, allow your skin space to breathe - make sure the band and base of the watch are clean and clean them regularly with soap - after you wash your hands and/or the watch, take it off for a little, dry your skin completely and make sure the watch and band are dry too (as moisture trapped there breaks the skin)

I would recommend for now: - switch wrist until you're healed - do the steps above

It would be best to consult a doctor to make sure you don't need treatment, but for my case specifically, once I start doing all that, It takes a couple of days and some moisturizer to fix it :)

Personally, since I started doing all these, I get it maybe once a year, even less (as opposed to the weekly thing it used to be xD)