How much do you use IEMs?
You seem to have a lot of cans in your sig, but I'm curious how new you are to IEMs or how frequent you use them.
I just want to make sure this isn't just a "getting used to" kind of thing and IEMs quite moderately annoy first time users or casual users for some time (months) until the ear gets accustomed to them. It does take a while for the ear to adapt. Things like tip choice, insertion amount, etc. all do affect ear fatigue and irritation. One option can very readily annoy in 15 minutes. Another option may be comfortable for 5 hours.
Your doctor should be able to say if the problem is allergic through testing. However, manual handling would also produce the allergic reaction.
Also, I would kind of advise not doing anything with the ear. You and others seem to do a lot of scratching, treating, touching the ear. This would moderately exacerbate the problem and help promote and spread infection. General hygiene is important of course but so is leaving it alone. The inner ear is relatively soft and sensitive tissue, so you really don't want to do more then you need to.
I hate to be a dick, but I sometimes lean towards blaming the user for their own problems. You just have to analyze what you're doing and question if you are doing the right things or if you are making the problem worse. IEMs are not natural. They are things to get used to and to build a tolerance for. This takes time. We have to learn to deal with the irritation during this time. We need to not make things worse by fiddling, scratching, irritating, and infecting. Make sure you use tips that fit well and are comfortable. They need to be the right size and shape to not cause irritation/pain with long use. Irritation and pain is not uncommon though.