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6-External auditory canal conditions

Conditions of the external auditory meatus

Congenital
Atresia (Greek) is a failure of development; in the case of the ear there may be a shallow blind pit or no opening at all. The pinna may be small (microtia) or missing (anotia) and the middle or inner ear may be poorly developed or even absent (Fig. 5.3).
Atresia of the ear is a feature of many syndromes in childhood and as congenital anomalies are often multiple, a careful assessment of the baby’s general health is essential. It is particularly important to assess the hearing. If the child has hearing impairment, rehabilitation in the form of hearing aids should commence immediately. Correction of the deformity of the external and middle ear can be delayed until the child is old enough to participate in the decision- making. The bone-anchored hearing aid and the use of titanium implants to mount a prosthesis have greatly improved the management of these children.

Wax
Wax or cerumen produced by the ceruminous glands in the outer ear migrates laterally along the meatus. Some people produce large amounts of wax but many cases of impacted wax are due to the use of cotton wool buds in a misguided attempt to clean the ears. Ears are ‘self-cleaning’!
Impacted wax may cause some deafness or irritation of the meatal skin. It is most easily removed by syringing (see Box 6.1).

ear wash
ear wax
Otitis externa
Otitis externa is a diffuse inflammation of the skin lining the outer ear canal. It may be bacterial or fungal (otomycosis). Irritation, desquamation, scanty discharge and a tendency to relapse are common. The treatment is simple, but success is absolutely dependent upon patience, care and meticulous attention to detail (see Chapter 5).
Causes
Some people are particularly prone to otitis externa, often because of a narrow or tortuous external canal. Most people can allow water into their ears with impunity; in others otitis externa is the inevitable result. Increased sweating and bathing in hot climates are predisposing factors. Swimming pools are a common source of otitis externa. Poking the ear with a finger or towel further traumatizes the skin and 
introduces new organisms. Further irritation leads to further interference with the ear, so causing more trauma. A vicious circle is set up.
Underlying skin disease such as eczema or psoriasis in the ear canal may produce very refractory otitis externa.
Ear syringing, especially if it causes trauma, may cause otitis externa.
Pathology
A mixed infection of varying organisms is typical; the most common are:
• Staphylococcus pyogenes
• Pseudomonas pyocyanea
• diphtheroids
• Proteus vulgaris
• Escherichia coli
• Streptococcus faecalis
• Aspergillus niger (Fig. 6.3)
• Candida albicans.
Symptoms
• Irritation (itchiness)
• Discharge (scanty)
• Pain (increased by jaw movement)
• Deafness (mild)
Fungal otitis externa
Signs
• Meatal tenderness, especially on movement of the pinna or compression of the tragus
• Moist debris, often smelly and keratotic
• Red desquamated skin and oedema of the meatal walls
Management
Aural toilet
Scrupulous aural toilet is the key to successful treatment of otitis externa. Clean the debris and keep the ear clean and dry. No medication will be effective if the ear is full of debris and pus. Aural toilet can be done most conveniently by dry mopping. Apply a piece of fluffed-up cotton wool about the size of a postage stamp to a probe and, under direct vision, clean the ear with a gentle rotatory action. Once the cotton wool is soiled, replace it (Fig. 6.4).
Gentle syringing is also permissible to clear the debris.
mopping

DressingsIf the otitis externa is severe, gently insert a length of 1cm ribbon gauze, impregnated with medication, into the meatus. Renew daily until the meatus has returned to normal. If it does not do so within 7–10 days, think again!
The following medications are of value on the dressing:
1. 8% aluminium acetate;
2. 10% ichthammol in glycerine;
3. steroid, e.g. Betnovate (TM);
4. other medication as dictated by the result of culture.
In fungal otitis externa you can use dressings of amphotericin, miconazole or nystatin.
If the otitis externa is less severe and there is little meatal swelling, it may respond to a combination of antibiotic and steroid eardrops. The antibiotics most commonly used are neomycin, gramicidin and framycetin but there are increasing worries about the use of aminoglycoside drops in the ear as if they reach the inner ear that can cause deafness. Ciprofloxacin drops, as used in eye drops, are preferable. Remember that prolonged use may result in fungal infection or in contact dermatitis
.
Prevention of recurrence
The patient should be advised to keep the ears dry, especially when washing the hair or showering. A large piece of cotton wool coated in Vaseline and placed at the entrance to the ear canal is advisable, and if the patient is very keen to swim it is worthwhile investing in custom-made silicone or rubber earplugs. Equally impor- tant is the avoidance of scratching and poking the ears. Itching may be controlled with antihistamines given orally, especially at bedtime. If meatal stenosis predis- poses to recurrent infection, meatoplasty (surgical enlargement of meatus) may be advisable.
Do not make a diagnosis of otitis externa until you have satisfied yourself that the tympanic membrane is intact. If the ear fails to settle, look again and again to make sure that you are not dealing with a case of otitis media with a discharging perforation.
Furunculosis
Furunculosis (‘boil’) of the external canal results from infection of a hair follicle in the lateral part of the meatus. The organism is usually Staphylococcus.
Symptoms
Pain
Pain is severe and exceptionally the patient may need opioids. The pain is made much worse by movement of the pinna or pressure on the tragus.
Deafness
Deafness is usually slight and due to meatal occlusion by the furuncle.
Signs
There is often no visible lesion but the introduction of an aural speculum causes intense pain. If the furuncle is larger, it will be seen as a red swelling in the outer meatus and there may be more than one furuncle present. At a more advanced stage, the furuncle will be seen to be pointing or may present as a fluctuant abscess.
Treatment
The insertion of a wick soaked in 10% ichthammol in glycerine (Glyc & Ic) or a steroid cream is painful at the time but provides rapid relief. Flucloxacillin should be given parenterally for 24 h, followed by oral medication. Severe cases may need incision under a general anaesthetic.
Analgesics – sometimes narcotics – are essential. Recurrent cases are not common – exclude immunodeficiency and take a nasal swab in case the patient is a Staphylococcus carrier.
Exostoses
Exostoses (bony overgrowths) or small osteomata of the external auditory meatus are fairly common and usually bilateral. They are much more common in those who swim a lot in cold water, although the reason is not known.
There may be two or three little tumours arising in each bony meatus. They are sessile, hard, smooth, covered with very thin skin and are often exquisitely sensitive when gently probed. Their rate of growth is extremely slow and they may give rise to no symptoms, but if wax or debris accumulates between the tympanic membrane and the exostoses, its removal may tax the patience of the most skilled manipulator. In such cases, surgical removal of the exostoses may be indicated and is carried out with the aid of the operating microscope and drill.
Malignant disease
Malignant disease of the auditory meatus is rare and usually occurs only in the elderly. If confined to the outer meatus, it behaves like skin cancer and can be treated by wide excision and skin grafting. If it spreads to invade the middle ear, facial nerve and temporomandibular joint, it is a relentless and potentially fatal disease. Pain becomes intractable and intolerable and there is a blood-stained dis- charge from the ear.
Treatment is by radiotherapy, radical surgery or a combination of the two. Treatment is not possible in some cases, and the outlook is poor in the extreme
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  1. Great tips regrading Inflammatory conditions. You provided the best information which helps us a lot. Thanks for sharing the wonderful information.

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