For the last week or so I have a big red itchy patch where I wear my Fenix 3.
According to my pharmacist I am allergic to Nickel which is what the underside of my Fenix 3 is made from.
Has this happened to anyone else? Is there an easy fix? I don’t really want to paint the underside with nail varnish if I can avoid it.

Stick a bit of heli-tape on the back?

I’m very surprised a watch as expensive as that uses nickel, which is a known allergen, instead of stainless steel, which even the cheapest Casio digital watches use. Are you sure it isn’t just where the watch is a bit tight, and you’re getting a sweat rash underneath? I have a cheap Bell & Ross knock-off, with the rubber/silicon type band, and my wrist got very red and itchy under the strap, to the extent I stopped wearing it, it was unbearable.
The watches I wear now have either leather or stainless mesh straps, and I don’t have a problem, however I do wear a G-Shock occasionally which has a mod allowing a nylon NATO strap, and I can get an itchy red patch underneath that, despite it being nylon against my skin; I tend to have it fairly tight, it’s not comfy if it’s loose fitting.

It’s definitely not too tight. I have no idea if it actually contains nickel but my pharmacist says it definitely looks like a nickel reaction. There’s a central circle in a different metal on the back and the inflammation exactly matches that.

Not happened to me but just put a piece of insulating tape over it.

I like mine but it doesn’t half bash my hand on rough decents, taken to wearing it over clothes.

Sorry about the hijack, but how are you guys liking the F3 (apart from the rash!), recently got a F2 which I really like.
Now thinking about an F3.

It’s great most of the time. It drops gps at times and sometimes the vibrate comes on constant. It needs hard resetting then it’s fine for a bit.

If I recall didn’t Garmin have a bit of an issue with this sort of thing on their fitness bands?

Edit: Nope. That was Fitbit. As you were.

Stick it on a Nato strap, then there’s two layers of nylon between your wrist and the back of the watch. I switched mine because I hate rubber straps with a passion, and the steel bracelet version seemed silly for sports purposes.

Strap came from SecTime, you need a 26mm one.

Unlikely that the watch is made from nickel. More likely it is made from stainless steel. Most common grade of stainless contains around 8% nickel. Pure nickel on its own would be too expensive and it’s not particularly workable. Might be nickel plated though.

it’s the nickel in the Stainless (and other items like buttons on jeans etc.) that does it.
for some reason I thought there was some strict EU limits on nickel content, and even Euro coins are low nickel, but can’t find where I thought I read that.

mine was from a cheap watch with cheap stainless back when I was about 15. Have a permanent scar from that.

One reason I wear one of those cheap G10 watches, with a fabric strap.