I had the same experience with my AW4 sports band. Knowing I have contact dermatitis I switched to a metal band. The problem disappeared.Had this happen to my on the underside of my wrist. It lasted for weeks when wearing the Apple sport band. I switched to another Apple sport band and no change. I switched to a cheap metal Milanese copy and irritation disappears.
I see other people have encountered this:
So I received my 42mm Space Grey Apple Watch Sport in the first week of May and wore it every day until mid-July, when, after a busy day of not really noticing anything wrong I noticed an itching/burning sensation in my wrist. I took off the watch and noticed it had caused a massive blister and...forums.macrumors.com
Four months ago, my parents gave me an Apple Watch for my 30th birthday. Though I was never a “watch guy” before this, I strapped...melmagazine.com
Wow, that's really interesting. I have had skin issues in the past so this is eye opening. Thanks for sharing it!I had the same experience with my AW4 sports band. Knowing I have contact dermatitis I switched to a metal band. The problem disappeared.
I was recently retested for contact dermatitis and found several more items I am allergic to. One of which is the following. You may be suffering from the same issue.
Thiuram mix [A] contains the following four substances: Tetramethylthiuram monosulfide, Disulfiram, Tetramethylthiuram disulfide, and Dipentamethylenethiuram disulfide. These substances are used as fungicides and pesticides, and in the manufacture of many rubber products. You are most likely to contact this substance when using, wearing, or handling natural or synthetic rubber products at work or at home.