While I experience itchy ears with seasonal allergies that responds to antihistamine, I also had a diagnosis of squamous cell carcinoma that started as an itch in my ear. That chronic itch with no pain persisted daily for over a year. I ignored it. The key here is that it was only one ear, where allergies usually cause bilateral symptoms. I finally initiated medical care when pain started. Was finally diagnosed 4 months and several doctors later, as there was nothing to see in my ear canal. This eventually resulted in a subtotal temporal bone resection at Mayo Clinic due to bony invasion by the tumor. So my advice is if it is only one ear, get it checked out sooner rather than later and be persistent in pursuing a diagnosis. Hope yours is just allergy.