Non-rubber shoes ideas/recommendations?

My spouse has a confirmed allergy to rubber(including latex and silicon) he works outside, has to wear close toe shoes and he sweats a lot outside.

Summer is the worst his feet get irritated and extremely itchy and peel. He itches them raw and makes himself bleed. He doesnt want to get steriod shots all the time he is terrified of needles. He changes socks 1-2x a day.

I have bought him athletes foot cream/foot fungus treatment he said it helps dry his feet and they start to heal in his sleep but his feet begin cracking and bleeding when he walks and the cycle starts all over again.

He swears he just needs shoes not made with rubber soles, rubber inserts or bottoms. I cant find anything besides foam crocs or leather sandals.

Anyone have ideas that may help? I feel we have tried everything.