Most patients are asymptomatic and IC may be an incidental finding diagnosed during a routine otological examination.

With regards to those patients who do present with manifest IC, partial conductive hearing loss is the most common symptom. Patients may also describe a feeling of fullness or pressure inside their ears. Otalgia and pruritus may be noted. Tinnitus has also been associated with IC. Dizziness and vertigo have been described and may result from functional impairment of the vestibular system.

Young children may be unable to provide such a detailed description of discomfort and pain. They may merely touch their ears repeatedly and present feeding and sleeping problems. Parents may note a reduced ability to hear.

About 50% of IC patients present with bilateral symptoms [5].

IC is diagnosed by means of a standard otological examination. Otoscopic examination of the external acoustic meatus does not allow for visualization of the tympanic membrane because a dense mass of cerumen plugs the ear passage. The skin lining the external auditory canal typically shows signs of inflammation, e.g., erythema and edema. Severity of IC as well as position and properties of the ceruminal mass should be assessed during this examination.

Removal of cerumen is the treatment of choice in symptomatic patients. Watchful waiting is indicated in the remaining IC patients, since the condition may resolve spontaneously within a few days.

Removal of cerumen should be carried out with utmost care in order to avoid inflicting damage to the external auditory canal or the tympanic membrane. In general, three therapeutic approaches can be distinguished: irrigation, application of ceruminolytics and manual removal [1]. These techniques are frequently combined, i.e., an irrigation with a solution containing ceruminolytics may be more effective than either method alone.

Irrigation

Irrigation may be carried out with saline solution or ceruminolytics, both warmed up to body temperature. Ideally, an irrigation is prepared by applying either of both liquids half an hour before the ear is rinsed. Removal of the ceruminal plug may be largely facilitated after soaking. With regards to the equipment, both ear syringes as well as oral jet irrigators are frequently used. However, the latter should not be utilized without putting on a supplementary ear irrigator tip. Excess pressure largely increases the risk for perforation of the tympanic membrane and other trauma. Many otolaryngologists use improvised irrigation system, which is a valid alternative as long as the physician disposes of the necessary experience to manage it [10].

Irrigation is contraindicated in patients presenting tympanic membrane perforations or that recently underwent surgery to reconstruct this organ.

Application of ceruminolytics

Ceruminolytics alone may resolve up to 40% of IC cases if applied regularly during prolonged periods of time. This is, however, not an option if patients suffer from hearing loss or otalgia. Ceruminolytics may also significantly improve the effectivity of irrigation. Distinct formulations are available, but superiority has not been proven for any particular product.

Similar to what has been stated about irrigation, ceruminolytics are not to be administered in patients that do or did suffer from tympanic membrane perforations.

Manual removal

Manual removal of cerumen is carried out with a curette, forceps, or suction device. It is the method of choice if both irrigation and ceruminolytics are contraindicated or if direct visualization of the procedure is required for any other reason.

IC has generally an excellent prognosis. Many patients presenting this condition remain asymptomatic for years. However, IC is associated with an increased risk of infection, inflammation and hearing loss. In fact, it has been estimated that one out of three children suffering from otitis media also shows IC. Considering the above given epidemiological data, this estimate corresponds to a threefold increase when compared with the general pediatric population.

Complications that may arise from removal of IC are traumas to the external auditory canal or the tympanic membrane, subsequent otalgia, otitis externa or media and further hearing loss.

Any pathologic condition interfering with the process of ceruminokinesis may ultimately provoke IC. For instance, anatomic anomalies such as a narrow or abnormally shaped external auditory canal may impede transport of cerumen towards the outer ear. This is not necessarily a congenital condition since space-occupying processes like hyperkeratosis, inflammatory swelling, osteophytes, tumors and a variety of other pathologies may secondarily restrict the lumen of the external acoustic meatus. Similarly, patients who are wearing hearing aids are plugging their ear passage and thus provoke retention of earwax.

Both changes in quality and quantity of cerumen may increase the risk of IC. Ceruminal fluidity decreases with age. While children generally dispose of well-viscous cerumen, earwax is rather dry and brittle in the elderly. An excess production of cerumen may result from dyskeratosis and other dermatological disorders.

Any ineffective attempt to remove cerumen from the external auditory canal may literally result in compaction of earwax in front of the tympanic membrane. Available transport mechanisms cannot clear this dense mass and continuous secretion of new cerumen adds to its volume. Therefore, neither cotton swabs and much less pencils, hair pins or other objects are suitable to clear the ear passage from earwax.

It has been estimated that 10% of all children and 5% of otherwise healthy adults suffer from IC, although the condition may be asymptomatic in a large share of these patients [4]. The small and narrow external auditory canal of pediatric patients may partially explain the observed high incidence in this age group. With regards to adults and as has been mentioned above, IC is most frequently observed in the elderly. Patients suffering from mental retardation pose another risk group.

A male-to-female ratio of 1.6 to 1 has been observed in a study comprising more than 200 patients [5].

The external auditory canal is lined with modified skin that nevertheless contains all characteristic appendages, i.e., hairs, sebaceous and sweat glands. Local sweat glands are particularly wide merocrine glands and are called ceruminal glands. Sebaceous glands, in contrast, are holocrine glands that open into hair follicles. Both sebaceous and ceruminal glands contribute to cerumen production. Earwax mainly consists of saturated and unsaturated long-chain fatty acids, alcohols, squalene and cholesterol [6].

Not only skin appendages but also skin layers found in the external acoustic meatus correspond to those of other regions of the body. Thus, cells originating from the basal layer of the epidermis pass through multiple phases of differentiation until being shed from the stratum corneum. However, they are not cleared as easily from skin surface and become part of the cerumen instead. It has been estimated that keratin accounts for more than half of the total weight of cerumen. But removal of keratin and cellular debris is only one of those functions fulfilled by cerumen.

Cerumen poses both a mechanical and chemical barrier against infection and infestation of the ear. Ceruminokinesis, i.e., the constant but barely noticeable outward flow of cerumen, transports keratin, debris, dust and other foreign bodies that may have entered the external auditory canal towards the outer ear. Furthermore, cerumen has antibacterial and antimycotic properties: Its pH is slightly acidic and cerumen contains lysozyme, an antibacterial hydrolase also contained in saliva, lacrimal fluid and nasal secretion. Although genetic variations between distinct types of cerumen have been described a long time ago, more recent studies could not find significant differences regarding incidence rates of otitis externa and ceruminal bactericidal activity [7] [8]. The presence of cerumen may, however, significantly diminish the risk of an ear infection in case of skin lesions within the external auditory canal. Of note, microbial evolution brought forth bacterial strains, mainly Staphylococcus spp. and Bacillus spp., able to survive in cerumen and utilize its components for growth and replication [9].

One of the main risk factors for IC is the ineffective attempt to remove cerumen from the external auditory canal inserting cotton swabs, hair pins, keys or other not suitable objects. This generally results in compaction of cerumen in the depth of the external ear. Patients should be advised against such behavior. Removal of cerumen should only be carried out by trained health care professionals.

Patients with an increased risk of IC may use ceruminolytics to prevent this condition.

The external auditory canal, also called external acoustic meatus, extends from the outer ear to the tympanic membrane and is therefore considered to be part of the external ear. The auditory ossicles (malleus, incus and stapes) are located within the middle ear and thus medial to the tympanic membrane. Finally, cochlea and vestibular system compose the inner ear. Here, mechanical stimuli originating from sound waves and body posture changes are translated into nervous signals.

A variety of mechanical and chemical barriers avoids damage to the sensitive parts of middle and inner ear. One of those barriers is cerumen produced in the external auditory canal. The latter is lined with skin that, similar to other areas of the body, contains sebaceous glands and sweat glands. However, due to anatomical and physiological modifications, local sweat glands are designated ceruminal glands. Both sebaceous and ceruminal glands contribute to cerumen production [1]. Furthermore, desquamated epithelial cells, hairs, debris and dust may constitute more or less physiological parts of cerumen.

Cerumen, as produced by sebaceous and ceruminal glands, is a yellowish, viscous liquid. Its properties change with time, dehydration and retention of debris and dust, as mentioned above: It loses fluidity, becomes darker, harder and brittle. It should nevertheless be transported towards the outer ear and be cleared from the external auditory canal by means of a process called ceruminokinesis, i.e., cerumen transport stimulated by masticatory movements. However, any condition interfering with ceruminokinesis prolongs the time of retention of cerumen inside the external auditory canal, promotes further hardening until finally, the ceruminal plug cannot be removed by any means. This condition is referred to as impacted cerumen (IC).

IC is a very common condition and has been estimated to affect about 5% of the population. The widely spread habit of trying to remove cerumen with cotton swabs, pencils or otherwise unsuitable objects increases the risk of IC [2]. It may be an incidental finding in asymptomatic patients, but the pathology may also cause significant hearing impairment, otalgia and dizziness and have patients present to the emergency room [3]. Thus, general practitioners, otolaryngologist and those professionals attending in emergency departments should all dispose of detailed knowledge regarding treatment options for IC.

External, middle and inner ear are the three main parts of the human ear. The external auditory canal is part of the external ear and extends from the outer ear to the tympanic membrane. It is lined by modified skin that disposes of hair follicles, hairs, sebaceous and sweat glands. Here, the latter are also called ceruminal glands. Similar to any other region of the human body, skin cells within the ear passage are shed after passing through distinct phases of differentiation. Hairs may fall out now and then.

Both sebaceous and ceruminal glands contribute to production of cerumen, a secretion that fulfills a variety of protective functions. On the one hand, it has antibacterial and antimycotic properties and thus reduces the risk of infection. On the other hand, it clears the external auditory canal from fallen hair, dead cells, debris, dust and any foreign body that may have entered the ear. Therefor, a constant outward flow is required. It is induced by chewing movements.

Any pathological condition that interferes with ceruminal flow will result in an accumulation of cerumen and all the aforementioned particles within the external ear. For instance, some patients have a very narrow external auditory canal; others may suffer from dermatological diseases that yield increased quantities of desquamated cells. Also, people wearing a hearing aid may involuntarily provoke an accumulation of cerumen which, in medical terms, is designated impacted cerumen.

One of the most common causes for impacted cerumen is the ineffective attempt to remove earwax with cotton swabs, hair pins, keys or any other not suitable object. The result of such measures generally is a compact mass of cerumen lodged in front of the tympanic membrane. The aforementioned mechanisms are insufficient to clear this mass and patients now have an increased risk for hearing loss, infection, inflammation and ear pain.

Removal of cerumen should only ever be carried out by a trained health care professional.

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