earwax

Definition of cerumen

Earwax is a waxy, yellowish-brownish secretion produced by the ceruminous and sebaceous glands located in the outer portion of the ear canal. Under physiological conditions, the earwax secreted slowly flows towards the outside of the auricle: having arrived here, earwax can be removed by careful washing.

Earwax has very important protective functions of the auditory duct:

1. Prevents the entry of foreign material into the external auditory canal (eg bacteria, fungi, insects, water, dust, etc.)
2. Lubricates the external auditory canal, reducing the risk of drying

Under certain circumstances, earwax tends to accumulate too much in the ear: in similar situations, the superabundant wax substance may occlude the external auditory canal and press against the eardrum, until it more or less considerably damages the hearing ability.

Generality

COMPOSITION

Earwax is a sebaceous and greasy secretion, which covers the epithelial surface of the external auditory canal. This is a waxy mixture with a viscous consistency, consisting of:

• Keratin (60%)
• Long chain saturated and unsaturated fatty acids, Alcohols, Squalene (12-20%)
• Cholesterol (6-9%)

Earwax also contains lysozyme, a protein substance (enzyme) that boasts antibacterial properties: it is believed, in fact, that lysozyme gives the discreet ear antimicrobial properties, being able to hydrolyse (destroy) the peptidoglycans that make up the bacterial wall.

Under physiological conditions, the pH of cerumen is slightly acidic (pH 6.1).

TYPE

There are two types of earwax:

1. Wet / wet earwax: most blacks and western Caucasians have this type of earwax. This sebaceous secretion has a moist appearance similar to honey and a color that varies from yellow to brown. The particular myeloma consistency of wet earwax is due to a higher concentration of lipids and pigment granules (approx. 50%).
2. Dry earwax: typical of Asians and Indians (American Indians), dry earwax has a greyish hue and a scaly consistency. Compared to the wet variant, dry earwax is composed of a lower percentage of lipids and pigment granules (approx. 30%).

From what emerges in the journal " Clinical Otolaryngology ", it seems that in humans the type of earwax seems to be genetically determined by a simple Mendelian character. The wet type is considered a dominant character, while the dry type is recessive.

Functions

As mentioned in the beginning, ear wax has very important functions for the ear:

• First, ear wax lubricates the external auditory canal, minimizing the risk of drying, itching and burning of the skin that covers it (humectant / lubricant function).
• Cerumen has antimicrobial effects: recent studies have shown the bactericidal and antifungal (antifungal) effect of earwax.
• The antibacterial action (mainly due to lysozyme) has proved particularly effective against infections caused by some bacterial strains: Haemophilus influenzae, Staphylococcus aureus and Escherichia coli .
• Cerumen inhibits the mycotic attack of the fungi most involved in otomycosis (Candida, Penicillium and Aspergillus). The antimycotic action of cerumen seems mainly due to two factors: presence of saturated fatty acids + slightly acid pH.

Cerumen and associated disorders

Under certain circumstances, ear wax can build up inside the ear canal, causing serious damage. In case of failed or incorrect cleaning of the ear, the earwax can obstruct the ear canal until it forms a solid concretion called earwax cap .

The earwax cap can cause different disorders that, if not treated, can seriously hinder the hearing:

1. Occlusion of the auditory canal
2. Otodynia: ear pain due to mechanical stimulation
3. Hearing impairment
4. Constant feeling of having "the ear closed"
5. Itching and ear pain
6. Ringing in the ears (tinnitus)
7. Alteration of equilibrium (similar to vertigo) → after a bath (eg swimming pool)
8. Increased risk of infection: mechanical "cleaning" with cotton sticks can create abrasions inside the ear canal, increasing the risk of bacterial or fungal infection.

What can promote ear wax accumulation?

• Hyper-production of earwax by the sebaceous glands (glandular hypersecretion) → It appears that wax production increases on certain occasions: for example anxiety, stress and fear stimulate the ceruminous glands to produce greater quantities of earwax.
• Ear disorders → stop the physiological sliding of the earwax towards the outside of the auricle
• Introduction of water into the ear canal → after a bath or a swim, the glands in the ear canal become impregnated with water, so earwax takes on a softer consistency. In such circumstances, earwax tends to obstruct the ear canal, thus creating "muffled" hearing and an unpleasant feeling of instability.
• Incorrect ear hygiene → both the lack of cleanliness and the incorrect hygiene of the ear can favor the accumulation of ear wax. For example, excessive mechanical cleansing, often performed with cotton buds, can compact the earwax towards the inside of the ear canal, compromising hearing.