I've had the itchy ear thing for years. I wasn't sure if it was due to steroid injections for some alopecia I was dealing with, or from an aspergillosis that I had in both ears when our basement had black mold more than 15 years ago. FYI at the time I did several courses of antibiotic ear drops and all that did was keep the environment moist and encouraged mold growth. It was not pretty at the end. Lotrimin in both ears helped clean up what the ENT didn't take out with tools.
So again, whatever the precipitating cause, the itchy ear thing bugged me for years. It would get worse if I used in-ear headphones or earplugs, which I did a lot.
For a long time I used the Dr. recommended 1% cortisol cream, and it kind of kept it at bay. I might need to apply it to the ear canal a few times a week to keep the itchig dowqn.
Once I got sick I decided I'd prefer to have as few hormonal inputs as possible, so I tried various "natural" lotions like from Standard Process and other places to no avail. By chance I decided to just use 2% lugol's iodine and do that every morning (swabbed with a qtip in each ear) and that seems to keep things calmed down.
Is the source fungal? I have no idea. I'm just glad to have found something that works. Hope it's helpful.