It is commonplace for clinicians to counsel patients against use of cotton buds or Q-tips to clean the ear.
The reason for such advice lies in the unique situation of the epidermis lining the external ear canal.
Whilst epidermis lining the surface of skin elsewhere in the body is subjected to friction (surface contact) to remove keratinocytes that have desquamated from the surface stratum corneum, evolution of deeper ear canals in land animals for protection of tympanic membrane presents a challenge for achieving that 'shedding of skin'.
This implies an alternative mechanism of removal of the superficial layer of stratum corneum of the tympanic membrane and the protected deep portion of EAC.
The interesting fact is that while skin cells elsewhere migrate vertically from the dermis to the epidermis (epithelial maturation), the ear canal skin, in addition, works like a 'conveyor belt' migrating the skin cells from the center of ear drum (tympanic membrane) outwards along the ear canal. This rate of this 'conveyor belt' motion is timed to coordinate rate of normal epithelial maturation.
Hence the instruction on the box of Q-tip: only use around outside of ear canal.
Reference:
1. An Ode To Ear Wax. http://variationselectioninheritance.podbean.com/2012/03/10/episode-35-an-ode-to-earwax/
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