Apple Watch rash

Hello,

I have been wearing my Apple Watch Series 3 with a white sports strap for around two months. I clean the strap very frequently, I do not shower or sleep in the watch and I have no allergies to any materials (at least I never had before) and I have never had a reaction to any jewellery or watches before. A rash has started to develop exactly where the strap sits, I have started trying to take the watch off for a day or so at a time to allow my skin to breath but I am unhappy doing this as I have become so used to relying on the watch. Has any one else has a similar reaction? Is there anything I can do to stop this happening?!