Just a random thought, when was his last check-up and bloodwork done? I am wondering if maybe his liver isn't functioning correcting to help filter toxins from his system and maybe they're building up and (for lack of a better grasp of wording) oozing through his skin?
I wonder if maybe a dose of IV fluids to help dilute and flush any toxins, maybe?
What about something holistic like milkthistle for liver support?
Best wishes for you. I am quite sure this is frustrating to have to experience.