Itchy Ears from Cotton Swab Use
Left uninterrupted, the external ear canal (EAC) is self-cleaning and generally does not need any help from us. Lining the entire length of the ear canal is a layer of insert tissue called keratin (stratum corneum). It's purpose is to protect the ear from bacterial, fungal, and viral assaults, to shield the EAC neuroreflexes from oversensitivity, and to maintain healthy pH, temperature, and moisture. In other words, an ear without keratin is not a healthy ear.
The keratin grows outward from the middle of the eardrum at the rate of about 1mm per day (or about 1/2" per month, the same rate your hair and nails grow). So, that if a piece of sand were placed on the eardrum today, by the end of three months it will have traveled the full-length of the canal, or about 1 1/2 inches. That is how earwax, debris, bacteria, and dead skin cells are removed on a continual basis.
But when one inserts a cotton swab or other mechanical object into the ear canal, they disturb this natural desquamation process and sometimes traumatize the ear. In every case, though, they remove some portion of the keratin layer, which leaves the EAC susceptible to infection. Itching is really a mild infection, and turns acute with a little more coaxing from a cotton swab or from bacteria floating in the environment.
Admittedly, we have found certain chronic conditions, such as diabetes mellitus, gout, and certain medications can inhibit growth of keratin in the EAC. In such cases, chronic ear conditions can persist, requiring professional attention from time to time.
But, the short answer to your question is that our ears are self-cleaning and rarely, during one's lifetime, will ever need "cleaning". While a cotton swab may be useful about 1/4" inch into the canal and around outer curves, I advise you not to attempt to remove wax from down inside the canal. Likewise, the practice of using hydrogen peroxide or boric acid in the ear canal is very caustic and destructive to ear health.
Letting nature take its course is generally the best ear care practice. For more detailed information please click to my article at http://www.audiologyonline.com/articles/but-what-s-wrong-with-1138.
Max S. Chartrand, Director of Research
DigiCare Hearing Research & Rehabilitation