After seven days we pulled his sensor on his arm and his skin looks beautiful!
We've been dealing with his adhesive allergy for a few months now and I think we've found a solution. We put a spray barrier down (Silesse, made by Trio Healthcare products) that was made of 100% silicone before putting the dexcom sensor on. It's a product that's made for ostomy appliances. I tried to not spray where the needle was going to be inserted, but I'm not sure if I avoided that part or not. I also used their Niltac (adhesive remover) to remove the sensor - it just fell off after a few minutes of spraying it. His skin looks so good, I sure hope that it continues.
Just a little plug for the company: I e-mailed them, told them our problem and asked for samples. I got a quick reply back and the samples were in the mail the next day!
I'll have to go through a few more sensors to know for sure the problem is truly resolved, but for now I'm very hopeful!