Bruising on arm under Apple Watch

I was on the hospital for about six weeks. When I returned home I put on my Apple SE watch which is about 3-4 years old to use it and I had a strange skin reaction. It looked like a circular bruise directly under the watch. I do not wear the watch tightly and the band is a mesh metal band that looks as if there would be adequate air circulation. I love my watch so going without it is not what I’d like to do but I don’t know that I can continue wearing it. Can anyone help?