After reading just the first post, my immediate thought was to ask how often you wash your hair and if you use a shower daily. Tubs have disadvantages but showers seem to have adverse effects on ears.

Then I continued reading the subsequent posts.

I do think seeing a dermatologist is your BEST bet for an answer and a solution.

There are many dermatological reasons for what you describe. Seborrhea is one of many. Some others already mentioned by other posters.

And it usually is not a one-time quick fix with many dermatology conditions. Some are of a chronic nature and need what seems to be perpetual care and or treatment.

Hope you find the culprit and a solution. I know how annoying this can be and it only gets worse by the uncontrollable scratching. The next thing you know, your ear is bleeding from the scratching. Then a scab forms and that becomes another cycle of which there seems no end. What you have described does not always cause an infection, but that can be another side event from the cycle.

Add to the mix, we can't SEE the inside of our own ears. I have often wished I could SEE what the doc sees when he looks in my ears and then just shakes his head. What does that head shake mean?

My guess would be,... see a dermatologist as it does sound more like their ballpark rather than an ENT specialist or just a GP.