Earwax is a necessary secretion of the outer third of the ear canal. The presence of earwax should not be thought of as dirty or not clean. References to the “clean ear” in the context of the removal and management of earwax are more about selling a service than helping patients understand their ears.
What is cerumen (earwax)?
Cerumen is produced in the outer third of the the ear canal. It is a mixture of secretions from oil (sebaceous) glands and less-viscous ones from modified sweat (apocrine) glands. The primary components of earwax are 60% shed layers of skin (keratin) and 12–20% saturated and unsaturated long-chain fatty acids, alcohols and, 6–9% is cholesterol.
There are two distinct genetically determined types of earwax: the wet type and the dry type.
East Asians and Native Americans are more likely to have the dry type of cerumen (Gray and flaky). 30-50% of South Asians, Central Asians and Pacific Islanders have the dry type of cerumen.
African and European people are more likely to have the wet type (honey-brown, dark orange to dark-brown and moist).
Function of earwax
Cerumen (earwax) prevents the loss of water from the skin (desiccation) and so maintains the skin’s normal health balance and appearance. This is largely due to the oil content of cerumen and its fatty acids.
Cerumen also has a bactericidal effect on some strains of bacteria. It is “bacteriostatic” as it may prevent some bacteria reaching deeper into the bony portion of the ear canal. Cerumen has been found to reduce the viability of a wide range of bacteria, including influenza and staphylococcus aureus. The growth of fungi commonly present in otomycosis is also significantly inhibited by human cerumen, however, cerumen is not an effective bactericidal against all pathogens.
As well as providing moisture and acidity, the sticky texture of earwax also acts as barrier to foreign bodies entering the ear canal. Examples could be debris such as sand or even an insect.
Migration process; the ear’s self-cleaning mechanism
You may be surprised to learn that the skin from your eardrum (tympanic membrane) to the outer part of your ear canal, is created from the centre of your eardrum called the Umbo.
New skin cells form at the Umbo and move outwards to the edge of the eardrum before moving outward in the canal, towards the entrance. The skin is smooth in the inner most two thirds of the ear canal as it moves over bone. When the skin reaches the outer third of the meatus, it enters the fleshy (cartilaginous) portion. This contains the cells that produce cerumen (earwax) as well as hair follicles. The skin wrinkles and eventually breaks, forming dead skin cells that flake off or mix with the cerumen depending on the dry or wet type of earwax produced.
The process of skin cells migrating out of the ear canal is sometimes called the “conveyor”. If a black dot were placed just off centre of the eardrum, it would take months for it to reach the outermost part of the ear canal. The movement (migration) of skin out of the ear canal is not fully understood and the speed of migration is not affected by jaw movement, as previously thought.
If the patient produces more earwax than the migration process (conveyor) can move out of the ear canal, or if hearing aids or other objects routinely push earwax back into the ear canal, a build-up of excessive earwax results.
See Excessive Earwax in the Learn More section below.