Skin issue

Skin issues- my son started skin issues on his elbows and hands when we moved to Fort Lauderdale in 2020. After a month in Boca Raton’s Florida Atlantic University College, it’s healing!! But then he came home for spring break and it flared up again, . It has to be the water right? I’ll take any help. and we’ve done all the things. No fragrances, diet, dermatologist, gut health, I’ve been trying to help his skin for five years🙏🏼