Somehow, your remark about the Pet Fountain reminded me of the problems one of our two cats (Ringo, the red tabby) had with 'kitty acne'. It turns out he got a bad case of that, according to the vet perhaps due to or exacerbated by the plastic cat food dishes we used.
Changing those to stainless steel combined with Animax (antibiotic/steroid) treatment cured that in the course of a few months. Interestingly, we still use a plastic water dispenser without problems. Of course, not all plastics are the same, particularly in regard to their content of the softeners presumed to be the causal agents of such dermal problems.
