Vivoactive 3 skin rashes

See this thread and response from Garmin: Rash or Irritation happening on my wrist

Wrote to them and no reply ... terrible customer support ! 

Former Member, email replies do take some time. My experience is anywhere from 1 day to 1 week. You should have seen this message when yo submitted the email support form:

"We typically respond within 3-5 business days, but it may take a bit longer during busy times of the year or if your query involves additional research. We're here Monday-Friday 7 a.m.– 7 p.m. CT. Closed weekends and holidays."

If you cannot wait, then I suggest calling them on Monday or opening a chat session. I had to connect with support this morning (Sunday in the US) and was assisted using the chat option within 5 minutes.

I'm having the same issue with my Forerunner 45S.  I've only had it for a few weeks.  It started after about the 3rd day wearing it.  I take if off at night and to shower.  I tried wearing it looser and cleaning it with rubbing alcohol at the end of each day.  It seems to be getting worse.  I get little blisters all around my wrist.  

I have had a rash on my wrist, but not from the sensor.  Mine has been from the band. It doesn’t matter if I wear it looser or not.  I have washed the /and and dried it.  It gets bad enough I can’t wear it for a couple of days, and the. I can wear it again.  But it makes my wrist itch.

does Garmin make a different band that might not cause this?  

I have replied to this elsewhere. I had the same problem. After trying various creams and soaps, drying the area constantly and cleaning the strap itself with isopropyl alcohol I gave up...and reluctantly bought a nylon strap for £10 from Amazon. I had my doubts. Didn't think it would work for my skin type and reckoned any cheap purchase from Amazon would be poor quality. I was wrong on both counts. The skin rash began to clear immediately. The nylon strap doesn't promote sweating or dampness. The area where the watch sits is totally dry and rash free (that's 10 days now). The strap is lightweight but well made and finished. I wish I had swapped the bands over from day one. The branding was "Fintie" or something similar. Don't waste time, effort and money chasing Garmin. You can solve this problem in no time. And you can pick and choose colours and styles.