Cerumen, colloquial known as ear wax, is a waxy substance which is secreted by 1000-2000 sebaceous glands and modified apocrine sweat glands of the external auditory canal (EAC) .
The external auditory canal is divided into two parts, the lateral cartilaginous portion (outer two-thirds) and the medial bony portion (inner one-third). The skin lining the inner bony meatus is only 0.1 mm thick and is tightly attached to the underlying bone and to the squamo-tympanic suture. It has no special function other than protection and clearance of desquamating keratin by migration. The skin lining the outer two-thirds of the canal is 10 to 15 times thicker and has a well-developed subcutaneous layer which contains hair follicles, ceruminous glands (slightly modified sweat glands) and sebaceous glands (which open into the hair follicles).
Ear wax, or cerumen, is a mixture of the secretion ofthese two types of glands and the exfoliated squamous epithelium (which is the major component). Cerumen also contains glycopeptides, lipids, hyaluronic acid, sialic acid, lysosomal enzymes and immunoglobulins, and exerts a protective, antibacterial effect by helping to maintain an acidic condition in the external auditory canal whilst also lubricating and protecting the ear canal. It has a pH of 5.2 to 7.0. Normally the wax,dust and dirt migrate in a lateral direction, the movement of the jaw contributing to this migration. Epithelial cells move off the tympanic membrane and then travel down the ear canal toward the meatus of the external canal. When Cerumen migrates toward the entrance of the canal foreign bodies such as dirt, dust, and other small particles adhere to it and are extruded with the cerumen when it is cast off from the canal having achieved its aim of removing dust and destroying bacteria and fungi.This “conveyor belt” process has been shown to be an ongoing process in most individuals. This self cleaning mechanism sometimes fails, however, causing retention or even impaction of wax. Cerumen impaction is more common in the elderly because as a person ages the cerumen glands atrophy, increasing the tendency of the cerumen to become drier.
Other factors that prevent the normal extrusion of wax from the ear canal (e.g.wearing a hearing aid, or using cotton buds) can further increase the chance of ear wax accumulating, while people with narrow or deformed ear canals or dermatologic disease of the periauricular skin or scalp are also susceptible to cerumen impaction. All these factors show that the development of an occluding wax plug is not associated with personal hygiene, but is rather a constitutional and unpreventable condition. Nevertheless, a common cause of excessive cerumen accumulation remains misguided attempts to remove wax with such instruments as cotton swabs, needles and hair pins which, besides traumatising the skin, often contribute to impaction and can impair the cleansing mechanism.
Ear wax is thus a normal secretion which becomes a problem in certain circumstances. The accumulation of wax has several sequelae:
(a) it can interfere with the view of the tympanic membrane; (b) it can cause a conductive hearing loss and hence may interfere with formal hearing assessment; (c) if in contact with the tympanic membrane it can cause discomfort and occasionally vertigo; and (d) it can contribute to infection.
Three effective therapeutic options are widely used:
1) Topical preparations (cerumenolytics, hydrogen peroxide, olive oil or almond oil, sodium bicarbonate, etc)
2) irrigation, in which wax is washed out of the ear canal by a jet of warm water). Ear syringing is contraindicated if the ear drum is perforated, if there is a history of mastoid surgery or chronic middle ear disease, or if the person has unilateral deafness (i.e. the ear in question is the person’s only hearing ear). Caution is also advised if there is a history of recurrent otitis externa or tinnitus, as it may aggravate these conditions.
3) manual removal other than irrigation such as ear curettes for hooking out the wax, or micro-suction. Combining one or more of these options, on the same day, or at intervals, is routinely used in everyday practice.Irrigation or manual removal can be used alone or after softening the impacted cerumen.
Cerumen removal is not without potential hazards. Complications of cerumen management are as follows - failure of wax removal; pain; tinnitus, or vertigo; otitis media or otitis externa; damage to the skin of the external canal; and perforation of the tympanic membrane. Other complications include bleeding (which is usually self-limited), infection, or disturbance in balance causing nausea and vomiting.