Hard to say what's really going on without a thorough check! But, what you've described does sound like a fungal infection to me, with the indication of spreading. Sometimes there are internal fungal problems that manifest externally -- you've mentioned Candida many times, but you could have a "mixed" fungal infection going on. Again, I'm taking a very wild guess without any evidence or proof.
The doctors say you have "allergies"? Allergies to what -- were those "allergies" identified as the cause for your symptoms? Did anyone do a skin scraping? Hair samples?