I Have Been Having Problems With Rashes. My Problem Started

I have been having problems with rashes. My problem started with rash in my temple region. My ears also became extremely dry and flakey and very red. My eyes were watering and the water was draining into the bags under my eyes. I went to my family doctor and the NP prescribed eye drops and Zertec. It helped with sneezing but the rash became worse behind my ears. I went to an ENT and he prescribed a six treatment with steroids. Everything cleared up. My main concern relates to my CPAP machine. I started using it again after 7 years. I sterilized all of my old supplies with vinegar water. That was prior to the original rash. I got a new sleep study doc and was able to order new supplies. I stopped using the CPAP while on the steroids and until I received the new supplies. I was clear of rash and I started using the CPAP machine again. The rash returned behind my ears. I stopped using the CPAP again. I again. Started taking the Zertec once a day. The rash went away and my ears are almost back to normal. I'm concerned about using the CPAP again. I now have a rash in the small of my back and itchy spots on my legs. Whew! After all of that what I want to know is what kind of Doc should I see to resolve this issue?