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AD_HTT_025_032___APR13_07 4/4/07 4:10 PM Page 25 How to treat Pull-out section w w w. a u s t r a l i a n d o c t o r. c o m . a u Earn CPD points on page 32 Complete How to Treat quizzes online (www.australiandoctor.com.au/cpd) or in every issue. inside Non-infectious external ear conditions Otitis externa Managing acute otitis externa Other conditions of the external ear The author External EAR CONDITIONS DR MICHAEL A TAPLIN, Ear, nose and throat surgeon (adult and paediatric), VMO Sydney Children’s Hospital, Randwick; Mater Misericordiae Hospital, North Sydney; Hunters Hill Private Hospital; and Prince of Wales Private Hospital, Randwick, NSW. Background INCREASED time in the water and humidity during the summer months favour bacterial and fungal infections of the ear, which are usually easily diagnosed and treated in the GP setting. Recent concern regarding bacterial resistance and medication ototoxicity have led to the development of sound guidelines for appropriate, safe and efficacious treatments. Anatomy and physiology The external ear is composed of the auricle (pinna), external auditory meatus (canal) and the lateral (epithelialised) surface of the tympanic membrane. The pinna acts to amplify and localise sound, as well as protecting the ear canal and the deeper structures (tympanic membrane, ossicular chain, middle-ear cleft and inner ear). The auricular cartilage deter- mines the pinna’s shape and is continuous with the cartilaginous portion of the lateral one-third of the ear canal. The prominent position of the pinna renders it susceptible to trauma. The external auditory canal is angulated (figure 1, page 27) and divided into cartilaginous (lateral one-third) and bony (medial twothirds) portions. The cartilaginous portion has loosely bound, thicker skin containing hairs, with numerous sebaceous and ceruminous (wax-producing) glands. In the bony portion the subepithelial layer of the skin is minimal and the skin is tightly adherent to the underlying periosteum. The skin in the deep ear canal does not produce wax and is particularly sensitive and susceptible to trauma. The epithelium of the lateral tymcont’d page 27 1-3 Before prescribing please review approved Product Information and PBS information found in the primary advertisment in this publication. Full PI available from Novartis Pharmaceuticals Australia Pty Ltd, 54 Waterloo Road, North Ryde NSW 2113. References: 1. Prexige (lumiracoxib) Australian Product Information. 2. Tannenbaum H, et al. Ann Rheum Dis. 2004;63:1419-1426. 3. Fleishmann R et al. Clin Rheumatol. 2005;25:42-53. NOVPRE0204/PRX236807 www.australiandoctor.com.au 13 April 2007 | Australian Doctor | 25 AD_HTT_025_032___APR13_07 4/4/07 4:10 PM Page 27 from page 25 panic membrane and ear canal has a unique selfcleansing mechanism. The skin migrates laterally, similar to a conveyor belt, towards the conchal bowl, where wax and keratin are shed. Failure to migrate leads to keratin and wax obstruction. Lymphatic drainage extends anteriorly to the preauricular and parotid nodes, posteriorly to the mastoid nodes and inferiorly to the cervical chain. The external ear is innervated by the cervical plexus (greater auricular nerve) as well as cranial nerves V, VII, IX and X (trigeminal, facial, glossopharyngeal and vagus). As a result, instrumentation of the ear canal may lead to throat tickle and cough, and throat or oropharyngeal pain can be referred to the ear (referred otalgia). Figure 2: Cerumen impaction. Figure 1 A: Normal ear canal. B: Marked angulation of the bony ear canal (coronal CT, petrous temporal bones). A B midis is the most common commensal organism. Pseudomonas aeruginosa and Staphylococcus aureus are the most common pathogens found in infected ears. Cerumen and wax Table 1: Microbiology of the healthy and infected ear Micro-organism Staphylococcus epidermidis Corynebacterium/diphtheroids Alpha-haemolytic streptococci Staphylococcus aureus Anaerobes (Escherichia coli, Proteus) Klebsiella, Enterobacter Pseudomonas aeruginosa Healthy ear (% of normal flora) 33-100% <33% <33% <33% <33% <5% <5% Aspergillus, Candida <5% Microbiology (table 1) The normal flora of the ear canal is similar to that of Otitis externa (% of normal flora) <5% <5% <5% <33% Unknown <33% 33-100% (more common in swimmers) 0-66% (more common in tropical climates ) the skin. Water exposure and excessive cleaning of the canal will alter the microbiological balance of the external ear. Staphylococcus epider- Ceruminous glands are modified sweat glands. Secretions from the sebaceous and ceruminous glands, together with desquamated epithelial cells and hairs, constitutes ‘wet’ wax. This is usually golden brown or ochre in colour and sticky. It is found more commonly in Caucasians and dark-skinned populations. ‘Dry’ wax is hard and darker in colour. There is usually a greater amount of compacted keratin squames and it easily forms a ball that may impact (figure 2). ‘Oriental’ wax, or ‘rice bran’ wax, is typically found in Asian races. It is dry, golden yellow and very flaky. Wax comprises lipid, protein and free amino acids as well as lysozymes and immunoglobulins. Together with an intact skin epithelium, it provides a sound immunological barrier. An acidic pH (4-5) discourages bacterial and fungal pathogens. People with diabetes tend to have significantly less-acidic wax (pH up to 8), and are thus more prone to recurrent and potentially serious infections. The average wax production is 2.81mg/week. There is no age or gender difference. The presence of wax is a sign of ear canal health, despite patients’ concerns at its presence or perceived excess. An infected ear produces little wax. Non-infectious external ear conditions Wax impaction and cerumenolytics (table 2) WAX impaction occurs in about 5% of the normal population. Studies have shown a greater prevalence in nursing-home and institutionalised patients (up to 30%). Patients who regularly use cotton buds (Q tips) to clean their ears, often push cerumen medially on to the tympanic membrane. This can lead to a conductive hearing loss. Cotton buds can lacerate the ear canal skin, breaking the normal immune barrier. This may lead to canal haematoma and otitis externa. ENT surgeons will often remove wax and keratin with the aid of a microscope. Wax curettes and gentle suction ear toilet is generally well tolerated and safe. Patients with tight stenotic ear canals or other ear disease such as tympanic membrane perforation should be reviewed by a specialist for aural toilet and further management. Ear syringing Ear syringing is often an effective measure for removing simple wax. This should only be performed by experienced doctors. Ideally the wax is initially loosened with the aid of a cerumenolytic. Syringing is contraindicated when there is gross wax impaction in the deep ear canal or when tympanic membrane perforation cannot be excluded. Syringing should also be avoided in patients with external ear canal infections, dermatitis of the ear canal, previous ear surgery and in patients with stenotic ear canals. Complications of ear syringing include perforation of the tympanic membrane, laceration to the ear canal skin and secondary otitis externa. Ear candles Ear candles are not recommended. Obstruction of the ear canal with paraffin and associated hearing loss and perforation of the tympanic membrane have been reported. Figure 3 A: Keratosis obturans. B: Keratosis obturans has expanded the tympanic bone on the left. A B Table 2: Preparations for wax removal Preparation Constituents Cerumol Chlorbutol, orthoTM perforation dichlorobenzene, para-dichlorobenzene, arachis oil Benzocaine, phenazone, TM perforation hydroxyquinoline sulfate, glycerol Carbamide peroxide TM perforation, otitis externa Auralgin Otic Ear Clear for Ear Wax Removal Waxsol Docusate sodium Hydrogen Hydrogen peroxide peroxide (H2O2) Sodium Sodium bicarbonate bicarbonate Olive oil Olive oil (pure) Distilled water Figure 4: Microforceps for removing wax and foreign bodies. Water Precaution Action (relative strength +) Lubricates cerumen plug rather than breaking down (+) Lubricates wax, local anaesthetic (+) Aqueous, softens and loosens wax (++) Breaks down wax (+++) Softens and loosens wax (++) Breaks down wax (++) Lubricates wax, ear canal Breaks down wax (+) Figure 5 A: Large exostoses with near complete canal occlusion. B: Moderate-size exostoses. C: Isolated osteoma at the bony-cartilaginous junction. A Osteoma and exostoses of the external ear canal Foreign bodies in the lateral ear canal are often easily visible and removed. Those in the deep ear canal are often wedged, and attempts at removal may cause significant pain and trauma to the ear canal and tympanic membrane. Blunt instruments such as microforceps are often best (figure 4). It is important to have good illumination. A light source mounted to a glasses frame is ideal. Resting part of the Osteomata of the ear canal are benign tumours. They are typically pedunculated and solitary, arising from the bony-cartilaginous junction of the external ear canal. Often found in the antero-superior portion, they rarely cause symptoms. Large tumours may obstruct the ear canal and cause conductive hearing loss (figure 5). Exostoses originate from the periosteum. Exposure to cold water causes a ‘refrigeration periosteitis’. The initial cold-induced vasoconstriction is followed by reactive hyperaemia. Low-grade inflammation then leads to a greater degree of bone deposition. The mature bone is arranged in layers, giving the histological ‘onion skin’ picture. Exostoses are often multiple and found in the deeper portion of the ear canal. They may contact the lateral surface of the tympanic membrane. Exostoses are common in Australia, especially in keen swimmers and surfers. In the early stages, exostoses are asymptomatic. However, with further growth there can be obstruction of wax and keratin. Water trapping predisposes to ear canal infection. Hearing loss and recurrent infections may require surgical removal. www.australiandoctor.com.au 13 April 2007 | Australian Doctor | TM perforation TM perforation TM perforation TM perforation, infection Otitis media, TM perforation B TM = tympanic membrane Keratosis obturans Keratosis obturans is an accumulation of keratin debris that forms a pearly white plug in the ear canal (figure 3). The precise aetiology is unknown but it is thought an increased rate of desquamation and poor epithelial migration are the cause. It is more common in younger people. Over time the keratin plug exerts pressure on the deep bony ear canal, leading to slow bone resorption. In extreme cases the keratin plug may erode into the mastoid bone. Keratosis obturans is best removed by a specialist. The ear canal may be very sensitive and the hand on the patient’s face will help stabilise hand movements and protect from inadvertent trauma associated with rapid head movements. Children are best treated by experienced clinicians or specialists. Occasionally an anaesthetic may be required. Live insects such as cockroaches cause particular patient distress, from fluttering and scratching movements. Rarely drum rupture may occur. Insects can be drowned with olive oil or flushed out with sterile water. Ticks are a particular hazard. They are often very small and easily missed. Severe ear pain with tympanic membrane inflammation (myringitis) and rupture can occur if the tick is not removed promptly. underlying skin inflamed or granulomatous. Ototopical antibiotics may be required, followed by a period of close surveillance. Foreign bodies in the ear canal C 27 AD_HTT_025_032___APR13_07 4/4/07 4:10 PM Page 28 How to treat – external ear conditions Otitis externa OTITIS externa is an inflammatory condition of the ear canal skin. The causes are infective or non-infective (inflammatory) (table 3). A healthy intact skin layer provides an effective physical and chemical barrier to bacteria and fungi. Changes to the micro-environment, such as repeated trauma, exposure to water or humidity and dermatitis, predispose to infective otitis externa. Changes to the pH appear to be the most significant predisposing factor to the development of bacterial otitis externa. Risk factors for otitis externa are summarised in table 4. Figure 6 A: Aspergillus niger otomycosis. B: Candida albicans otomycosis. A B Bacterial Fungal Viral Necrotising (bacterial/fungal) Non-infective Dermatitis (inflammatory) Seborrhoeic dermatitis Atopic dermatitis Atopic dermatitis often presents with itchiness, crusting, fissuring and oozing. As with allergic rhinitis, conjunctivitis and asthma, there is often a strong family history. Patients with atopic dermatitis are prone to develop secondary staphylococcal infection or viral superinfection (herpes, vaccinia, molluscum contagiosum). Topical neomycin has been shown to cause contact sensitivity in 5-15% of patients. Patch testing suggests an even higher rate. Neomycin is a broad-spectrum aminoglycoside antibiotic contained in Kenacomb preparations. It is particularly effective against Gram-negative bacteria, but not Pseudomonas aeruginosa. Cosmetics, soaps, detergents, shampoos, hair sprays, hair dyes and preservatives can cause hypersensitivity. Nickel, silver, rubber and 28 Dosing Three drops bd for 10 days Adverse reaction Burning (polyethylene glycol) Advantages Effective antifungal. Some antibacterial action Kenacomb Otic Three drops tds Stinging, neomycin Covers bacteria allergy, ototoxicity and fungus Ear Clear for Swimmers Ear (acetic acid in isopropyl alcohol) Aquaear (acetic acid in isopropyl alcohol) Four drops each ear after swimming Stinging Four drops after water exposure Stinging Table 3: Classification of otitis externa Infective Non-infective otitis externa — dermatological conditions Seborrhoeic dermatitis is found in oil-rich areas of the skin, especially in and between the eyebrows, around the base of the nose and behind the ears. The skin of the conchal bowl and ear canal is itchy, dry and flaky. Seborrhoeic dermatitis is associated with the yeast Malassezia furfur. Antifungal creams and ointments such as Canesten and Nizoral may be useful. Topical steroid such as mometasone (Elocon) lotion are also effective. A once- or twice-weekly application of a steroid achieves some degree of prophylaxis. The anti-dandruff shampoos are also good, particularly if there is scalp involvement. Patients should avoid the temptation to scratch the ear or insert paper clips, pins and cotton buds, as these will further traumatise the skin and predispose to secondary bacterial infection. After swimming and hair washing, gentle use of the hair dryer on a low setting will help dry out the ear canal. Table 5: Ototopical therapy for otomycosis Ototopical LocacortenVioform Acute diffuse Acute localised (furunculosis) Chronic Otomycosis Herpes zoster oticus ‘Malignant’ Seborrhoeic Atopic-eczematous, iatrogenic Psoriasis Table 4: Predisposing factors for otitis externa Predisposing factor Water exposure Wax Dermatological Trauma Anatomical Localised ear disease Systemic disease Radiotherapy Assistive hearing devices Examples Seasonal humidity (‘tropical ear’), swimming, water sports Impaction, removal or loss of physical protection, change of pH Eczema, seborrhoeic, psoriasis Foreign bodies, cotton buds, paper clips, safety pins Narrow/long/hairy ear canals, stenosis, exostoses Tympanic membrane perforation discharge, cholesteatoma Diabetes, immunocompromised Head and neck, CNS malignancy Hearing aids, ear plugs, diving suits, mobile phone ear pieces Figure 7: Staphylococcal furunculosis. plastics used in ear pieces and hearing aids may also act as an irritant. Nickel is the most common contact allergen, affecting about 10% of people with pierced ears. Psoriasis and discoid lupus also have ear-canal manifestations Viral otitis externa Herpes zoster oticus (Ramsay Hunt syndrome) is the most frequent viral infection of the external ear. The virus lies dormant in the geniculate ganglion (facial nerve) with characteristic vesicular eruption involving the skin of the external ear. This is easiest to detect in the conchal bowl. Initially the patient may complain of a hot burning sensation within the ear that rapidly develops into severe pain. Mastoid pain is also very common and often precedes a facial palsy. The recovery of full facial function is usually less than in iatrogenic facial palsy (Bell’s palsy). | Australian Doctor | 13 April 2007 Figure 8: Diffuse otitis externa (note canal oedema). Loss of taste over the anterior two-thirds of the tongue and decreased lacrimation may occur on the infected side when the chorda tympani nerve, a branch of the facial nerve is involved. Hearing loss, tinnitus or vertigo indicate inner-ear involvement. Vesicles on the soft palate indicate glossopharyngeal involvement. Antivirals (such as, valaciclovir or famciclovir) with or without oral steroids are indicated for facial nerve involvement. Warm compresses and analgesia act as supportive therapy. Incomplete eyelid closure requires extreme vigilance to prevent exposure keratitis and possible long-term visual impairment. Consultation with an ophthalmologist might be necessary. Fungal otitis externa (otomycosis) Fungal species colonise the healthy ear, growing on VoSol (propylene Five drops tds glycol diacetate) (treatment for swimmer’s ear) Two drops bd for prophylaxis Stinging Acid pH prevents fungus and bacteria. Drying agent Low pH prevents bacteria and fungus Prevention of and bacterial OE Disadvantages Viscous and yellow. Often difficult to administer drop. Precaution with TM perforation Viscous. Potentially ototoxic. Neomycin sensitivity. Difficult to administer drop. Contraindicated with TM perforation Poor compliance due to stinging. Not to be used with TM perforation Poor compliance due to stinging. Contraindicated with dermatitis or TM perforation Poor compliance due to stinging. Contraindicated with TM perforation TM = tympanic membrane desquamated keratin and wax. Species such as Candida albicans and Aspergillus niger or Aspergillus flavus can become pathogenic, especially in patients with dermatitis. Warm, humid and wet conditions favour their growth. Fungal otitis externa may also occur after an episode of bacterial otitis externa has been successfully treated with ototopical antibiotic drops. Patients taking drops long term are susceptible, as the normal flora of the ear canal is removed. Symptoms of otomycosis include itching, local irritation and persistent otorrhoea. Some patients complain of a “squelching” sensation and minor pain. Severe pain is less common. Occasionally a patient may be completely asymptomatic. In the early stages of Aspergillus otitis externa, debris may resemble cotton wool or a white plug. Tiny grey-black conidiophores are often seen with A niger (figure 6A). In severe cases there may be ulceration of the ear canal and erosion or rupture of the tympanic membrane. Extensive white ‘blotting paper’ debris is typical of Candida species (figure 6B). Keratin debris appears very similar and sometimes a swab might need to be taken for fungal culture to confirm infection. Sprouting hyphae are often seen with the aid of the otological microscope. Treatment success relies on accurate diagnosis and thorough aural toilet. Removal of fungal debris with a small curette, cotton wool brooch or suction is best. Syringing with water provides fungal colonies with ideal conditions for proliferation and should be www.australiandoctor.com.au avoided. Aural toilet is sometimes needed every second or third day to prevent rapid re-accumulation. Topical antifungal creams such as clotrimazole (Canesten), miconazole (Daktarin) and bifonazole (Mycospor) can be placed around the circumference of the ear canal or, more simply, placed to fill the ear canal. Ototopical antifungal drops (table 5) are also effective. After aural toilet, I prefer Locacorten-Vioform drops, which contain the steroid flumethasone and the sound fungicidal clioquinol, as well as being bacteriostatic against Gram-positive bacteria and moderately inhibitory against Gram-negative bacteria. Kenacomb drops contain nystatin, which is effective against C albicans. The other constituents are neomycin (for Gram-negatives), gramicidin (for Grampositives) and the steroid triamcinolone. Neither antifungal drop should be used with a tympanic membrane perforation. Long-term prevention of otomycosis involves treating underlying dermatitis and avoiding water. Drying agents containing acetic acid with or without alcohol are good, but contraindicated with a tympanic membrane perforation and when there is a break in the skin, as they may cause severe pain. Fungal otitis externa is treated aggressively in the elderly or immunocompromised host as infection beyond the ear canal skin involving the petrous bone and skull base leads to osteomyelitis (malignant otitis externa). Oral and IV antifungals (amphotericin, ketaconazole, itraconazole) are often required. Acute localised otitis externa (furunculosis) A furuncle is a localised staphylococcal abscess arising from the base of a hair follicle (figure 7). In the ear canal, they only occur in the lateral cartilaginous portion. As the skin is tightly adherent to the underlying perichondrium, movement of the pinna causes significant pain. Treatment involves systemic and/or topical antistaphylococcal antibiotics. If the abscess is pointing, drainage with a sterile hypodermic needle will accelerate resolution. The ear canal may also be packed with an otowick or antibioticimpregnated vaseline gauze (Xeroform). Acute diffuse otitis externa In essence, acute otitis externa is a cellulitis of the ear canal skin and the underlying subdermis. Acute diffuse otitis externa may involve the ear canal, pinna or tympanic membrane. In North America, 98% is bacterial, due to P aeruginosa (20-60% prevalence) and S aureus (10-70% prevalence). Early infection (‘swimmer’s ear’ or ‘tropical ear’) is one of the most common infections presenting to primary care physicians. The annual incidence in the US and Canada is between 1:100 and 1:250 of the general population. Regional variations depend on age and location. Lifetime incidence is about 10%. Acute diffuse otitis externa is rapid in onset (usually within 48 hours) and associated with erythema and oedema of the ear canal skin. There may be clear and/or odourless secretions and some desquamated debris within the canal. Pain is mild and there AD_HTT_025_032___APR13_07 4/4/07 4:10 PM Page 29 Table 6: Clinical signs and symptoms of acute otitis externa Table 7: Differential diagnosis of acute otitis externa Signs and symptoms Comment Otalgia/pain (70%) Often intense except in the early stage. More pronounced with bacterial infections Usually circumferential. Blebs and bullae may be present May extend into the pre- and post-auricular soft tissues Mild-moderate. May be green or white. Usually not copious or serosanguineous. Does not usually stain the bed sheets White, creamy. If fungal, spores may be seen, eg, black conidiophores of Aspergillus niger. Pseudomonas aeruginosa has a typically green hue Early stages and healing phase. More common with dermatitis and fungal otitis externa Depends on canal stenosis and debris. More common with acute otitis media Oedema Erythema Otorrhoea Debris in the canal Itchiness Hearing loss may be discomfort with movement of the tragus (classic sign). The tympanic membrane may appear dull. As the inflammation increases, the patient complains of increasing pain and itching. Oedema tightens the ear canal and there is further accumulation of debris. Tragal pressure and pulling of the pinna causes greater pain and it may be difficult to examine the ear canal with the otoscope. Visualising the tympanic membrane can also be difficult. In severe acute otitis externa there may be cellulitis and oedema of the preand post-auricular tissues. Extension into the upper neck is possible, though rare. The pain can be very severe, Clinical presentation History Pain Fever Discharge Associated features Season Acute otitis media (with perforation) Chronic suppurative otitis media* Often severe Before perforation Rare Thick, mucopurulent Swimming, warm or humid weather Before rupture Often copious, may be serosanguineous URTI, grommet in situ Summer Winter or spring Uncommon, unless complication present Rare Purulent, chronic or recurrent Chronic tympanic membrane perforation ± cholesteatoma Variable Physical examination Ear canal Tender tragus or pinna, oedema, erythema Figure 9 A: Chronic suppurative otitis media with attic cholesteatoma. B: Radiation osteitis (previous radiation exposure with resultant osteitis is a predisposing risk factor for the development of otitis externa). A Otitis externa Tympanic membrane B Organisms Normal or mild inflammation. May be difficult to visualise Pseudomonas aeruginosa, Staphylococcus aureus (skin pathogens) Copious discharge. Pain is related to associated secondary otitis externa Chronic discharging ear, offensive odour. Pain might indicate complication Perforated, red, inflamed, Larger perforation, opaque. Gentle forced squamous or keratin Valsalva manoeuvre may debris. Consider produce bubbles cholesteatoma Streptococcus pneumoniae, Pseudomonas Haemophilus influenzae, aeruginosa, Moraxhella catarrhalis Staphylococcus (respiratory tract pathogens) aureus, coliforms, others *Includes tympanostomy tube otorrhoea required. In children examination of the tender ear is even more challenging. Acute otitis media is more common, particularly in the younger age groups. Otitis externa is more likely if the child is older (12-18 years) or if there is: ■ A history of swimming. with associated fever, nausea and vomiting. Patients avoid sleeping on that side and a significant number cannot sleep at all because of pain and distress. Simple analgesia such as paracetamol, low-dose oral opioids and NSAIDs may appear ineffective. Parenteral opioids are sometimes A history of trauma to the ear canal and/or excessive cleaning. ■ An underlying skin disorder. ■ A history of chronic suppurative otitis media. ■ Hearing aid use. ■ Immunocompromise. ■ Diabetes. A microbiology swab and culture can often help distin■ guish between external and middle-ear infections. Antibiotic sensitivity will provide a guide for appropriate antimicrobial therapy. Tympanometry is a noninvasive investigation that helps distinguish between an intact or perforated tympanic membrane. It is generally well tolerated by chil- dren. However, the patient with acute otitis externa will often experience significant pain on insertion of the ear probe. In the acute setting it has limited usefulness. Table 7 highlights the clinical differences between otitis externa, acute otitis media and chronic suppurative otitis media (figure 9). Managing acute otitis externa Evidence-based medicine COMPARED with other subspecialities there are relatively few guidelines relating to otorhinolaryngological diseases. An algorithm for the management of diffuse acute otitis externa is shown in figure 10 (page 30). In 2006, the American Academy of Otolaryngology – Head and Neck Surgery produced an evidence-based guideline* for the treatment of acute otitis externa, based on numerous clinical and scientific studies as well as large metaanalysis. The information below is adapted from this guideline. Table 8: Topical antimicrobials for diffuse acute OE Topical agent Components Dosing Side effects Advantages Disadvantages Sofradex Framycetin, gramicidin, dexamethasone Neomycin, gramicidin, nystatin, triamcinolone 2-3 drops tds or qid 2-3 drops bd or tds Ototoxicity Broad-spectrum, steroid reduces pain, inexpensive Broad-spectrum, steroid, reduces pain, antifungal component Ciproxin HC Ciprofloxacin hydrochloride, hydrocortisone, benzyl alcohol 3 drops bd Headache, leaves precipitate (skin cast) within ear canal Ototoxicity with TM perforation, poor compliance Ototoxicity, hypersensitivity, viscous, poor compliance, neomycin not effective against Pseudomonas aeruginosa Relative cost, contraindicated with TM perforation (contains alcohol preservative) Ciloxan 0.3% ear drops Ciprofloxacin hydrochloride (3mg/mL) 3 drops tds Burning (mild) Locacorten-Vioform Flumethasone, clioquinol, polyethylene glycol Chloramphenicol, boric acid, borax, phenylmercuric nitrate 3 drops bd Itching/burning 4 drops qid Local irritation, blood dyscrasia, superinfection Kenacomb Ototoxicity, neomycin skin hypersensitivity, burning Prevention There is level C evidence for efficacy of the following measures in preventing otitis externa: ■ Avoiding water and humidity (swim plugs, drying agents, hair dryer on low setting). ■ Avoiding trauma to the ear canal (foreign objects, excessive removal of wax). ■ Avoiding ear syringing in patients with tight stenotic or tortuous ear canals. ■ Treating underlying dermatitis (seborrhoeic, atopic). ■ Avoiding ear drops containing neomycin (skin hypersensitivity in 5-15% of patients with chronic otitis externa). *American Academy of Otolaryngology – Head and Neck Surgery. Clinical practice guideline: acute otitis externa. Otolaryngology – Head and Neck Surgery 2006; 134 [Suppl 4S (April)]. Chloromycetin ear drops High efficacy against Pseudomonas aeruginosa, Staphylococcus aureus, Proteus species. Steroid reduces pain. No fluoroquinolone ototoxicity No ototoxicity, can be used with TM perforation. Recently released as otic preparation Very good against fungal otitis externa, steroid reduces itch and pain Bacteriostatic across a wide range of pathogens No steroid component Caution with TM perforation. Viscous, difficult to instil Contraindicated with TM perforation TM = tympanic membrane Treating discharging middle ear (chronic suppurative otitis media, tube otorrhoea) ■ Controlling systemic disease (diabetes, HIV infection, immunocompromise). ■ Avoiding radiotherapy to the head and neck. ■ Pain management This is a major goal in the management of acute otitis externa. There is level B evidence for the following measures: ■ Mild-moderate pain usually responds to paracetamol or www.australiandoctor.com.au NSAIDs alone or in combination with an opioid (codeine, oxycodone). Fixed-interval analgesia may be more effective than when used as needed. Although popular, adjunctive therapies such as heat, cold and distraction are of unproven value. ■ Benzocaine-containing otic preparations (Auralgin Otic) can provide topical anaesthesia for the ear canal, although there have been no clinical trials to establish efficacy. The use of these drops may allow disease progression to be masked. Topical benzocaine may induce a contact hypersensitivity dermatitis. Topical steroids added to ototopical antibiotic drops (Cipro-HC, Sofradex) have been shown to hasten pain relief. Initial therapy — topical vs systemic There is level B evidence supporting the use of topical vs systemic therapy in the initial stages. Topical preparations are recommended for uncomplicated acute otitis externa (no osteitis, abscess, cont’d next page 13 April 2007 | Australian Doctor | 29 AD_HTT_025_032___APR13_07 4/4/07 4:10 PM Page 30 How to treat – external ear conditions from previous page Figure 10. Algorithm for the management of diffuse acute otitis externa. middle-ear disease, tympanic membrane perforation or recurrent episodes of infection). Coexistent diabetes, immunosuppression or spread of disease beyond the ear canal into the pinna, skin of the face or neck or deeper tissues (malignant otitis externa) requires referral to an ENT specialist and use of oral or IV therapy. Studies have shown that 20-40% of patients with acute otitis externa receive oral antibiotics, often as well as topical antimicrobials. Many of the oral antibiotics are inactive against Pseudomonas and S aureus, the most common pathogens. Treatment with penicillins, cephalosporins or macrolides increases disease persistence, and treatment with cephalosporins also increases recurrence. Ototopical therapies have several advantages over systemic therapy for uncomplicated, diffuse acute otitis externa. These include: ■ High concentration of medication at the site of infection (100-1000 times higher than that achieved with systemic therapy). ■ Low risk of developing antibiotic resistance. ■ Minimal systemic adverse effects (rashes, vomiting, diarrhoea, allergic reactions and altered nasopharyngeal flora). ■ Relative ease of administration. Which topical therapy? Level B evidence supports the following recommendations regarding choice of topical therapy. It is not always necessary to treat diffuse acute otitis externa with an antibiotic. Several acidifying solutions are available, including: ■ Acetic acid. Patient >two years with diffuse acute otitis externa: ■ Ear pain ■ Discharge ■ Tragal tenderness Vesicular eruption Treat for herpes zoster oticus Yes No Analgesia according to pain severity Extension beyond ear canal Referral to ENT specialist ■ May require admission and parenteral antibiotics. ■ Management of underlying conditions Yes No Tympanic membrane perforation (known or suspected), including in situ grommet Yes Non-ototoxic topical therapy (ciprofloxacin) No Topical therapy Patient preference, cost, compliance Requires aural toilet +/- otowick insertion May require referral to ENT specialist Yes Obstructed ear canal No Educate patient ■ Water avoidance ■ Drop delivery Clinical improvement in 24-48 hours Clinical re-assessment ■ Swab culture ■ Aural toilet ■ Assess for compliance ■ Exclude other illnesses No Yes Complete course Treat modifying and redisposing factors ■ Dermatitis ■ Ear canal trauma ■ Water exposure ■ Hearing aids ■ Diabetes/ immunosuppression Boric acid. Aluminium acetate. ■ Silver nitrate. ■ Glycerine-ichthammol. ■ ■ Gentian violet. These agents are inexpensive and have been used for many years, particularly in developing countries. They are unlikely to cause bacterial resistance. Ototopical antibiotics contain either an aminoglycoside (gentamycin, neomycin, tobramycin, polymyxin B and framycetin) or fluoroquinolone (ciprofloxacin, ofloxacin). Aminoglycosides have been around for longer, are generally cheap and have a good antibacterial spectrum for acute otitis externa but in recent years, aminoglycoside ototoxicity (cochlear and vestibular) has become more apparent. Topical gentamicin drops delivered via a middle-ear catheter or grommet (ventilating tube) are sometimes used to perform chemical labyrinthectomy in patients with Ménière’s disease. Aminoglycosides and topical alcohol-containing agents should not be used when the tympanic membrane is perforated and the middle-ear space is open. The risk of ototoxic injury outweighs the benefits compared with non-ototoxic antimicrobials with equal efficacy. Ototopical antimicrobial treatments for acute otitis externa are shown in table 8 (page 29). Meta-analysis has shown no significant difference in clinical outcomes (clinical and bacteriological cure rates) for patients with acute otitis externa with regard to use of: ■ Antiseptic vs antimicrobial. ■ Quinolone vs non-quinolone antibiotic. ■ Steroid-antimicrobial vs antimicrobial alone. Regardless of the topical agent used, 65-90% of patients have clinical resolution within 7-10 days. ■ Recent studies have shown significant differences in the rapidity of treatment response and symptom resolution. The addition of hydrocortisone to ciprofloxacin significantly reduced median ear pain by one day. Drug delivery Drug delivery may be difficult if there is extensive debris in the ear canal or skin oedema. Self-administration can also be difficult. Level C evidence exists for the following guidelines regarding delivery of topical therapy. Ideally the ear canal should be cleared of inflammatory debris, obstructing wax or other foreign body. Aural toilet can be done with hydrogen peroxide, but best results are achieved with the use of suction or cotton wool brooch. If canal oedema prevents adequate delivery of drops, an otowick, comprised of compressed cellulose, can be placed in the ear canal. The wick is simply inserted dry into the ear canal using forceps. Ideally the visible end should sit flush with the level of the conchal bowl. The wick expands when exposed to moisture and optimises drug delivery while reducing canal oedema. Otowicks should be changed after 48 hours. Drops should be applied with the patient lying down with the affected ear upwards. After the drops have been placed, instruct the patient to rub the tragus, as this eliminates any trapped air in the ear canal, and allows the drops to reach the medial ear canal and tympanic membrane. If the patient states that the drops can be tasted, tympanic membrane perforation should be suspected, even if not clinically apparent. Other conditions of the external ear Malignant (necrotising) otitis externa MALIGNANT otitis externa is an aggressive and invasive form of otitis externa. It typically affects elderly or immunocompromised patients and those with diabetes. Important to the pathophysiology appears to be alteration of the canal pH. The aetiology may be bacterial or fungal. P aeruginosa is the most common pathogen. The infection starts in the ear canal skin then extends into the temporal bone. Skull base osteomyelitis may extend medially to involve multiple cranial nerves and the intracranial contents. The diagnosis is based on the clinical findings. A hallmark of malignant otitis externa is an area of granulation tissue on the floor of the cartilaginous ear canal, near the junction of the bony portion of the ear canal. The associated pain can be severe and response to standard treatment can be slow. A poor clinical response to treatment, together with other risk factors such as diabetes, being elderly or immunocompromised, neces- 30 Figure 11: Gallium scan for skull base osteomyelitis. Figure 12 A: Squamous cell carcinoma of the ear canal. B: Lateral temporal bone resection. C: The ear canal is transected. D: Superficial parotidectomy. A B tures of the temporal bone, skull base, parotid and neck necessitate wide surgical excision (figure 12) with adjuvant chemo/radiotherapy. Bullous myringitis sitates urgent review by an ENT specialist. A gallium scan (gallium 67 citrate) (figure 11) indicates the extent of inflammation and quickly returns to normal with the resolution of infection. Technetium bone scans reflect activity in osteoblasts and osteocytes. These scans may remain positive for many months after clinical resolution. When the condition was first described in the late 1950s / early 1960s, the mortality rate approximated 80%. Prognosis is now much improved. Treatment requires IV and prolonged oral antibiotics, often with adjunctive topical therapy. Effective antibiotics include ciprofloxacin, piperacillin-tazobactam (Tazocin), ticarcillin-clavulanate (Timentin) and cef- | Australian Doctor | 13 April 2007 C D tazidime. Adjuvant hyperbaric oxygen therapy has also achieved good results in selected centres. Malignant tumours of the external ear Melanoma, squamous cell and basal cell carcinoma commonly affect the sunexposed auricle. These are often easy to diagnose. When malignancies involve the ear canal, diagnosis can be diffi- cult and may be delayed. Rare tumours involving skin adnexal structures and minor salivary glands can also occur. The clinical presentation may be similar to that of otitis externa with a history of chronic ear discharge, a mass in the ear canal, hearing loss or facial palsy. Metastases are present at the time of diagnosis in 5-15%. Extension into deeper struc- www.australiandoctor.com.au This is a distinct form of otitis externa, characterised by fluid-filled haemorrhagic blebs on the tympanic membrane and deep ear-canal skin. Severe local pain followed by a spontaneous haemoserous discharge is common. Influenza viruses and Mycoplasma pneumoniae are suspected causative agents. A conductive hearing loss as a result of secondary serous otitis media may occur. In rare case the inner ear can be involved, with clinical sensorineural hearing loss and vertigo. Treatment is generally supportive, with analgesia and prevention of secondary bacterial infection. involved include the nose, eustachian tube, larynx, ribs and joints. The condition is more common in women aged 3545. The pinna may appear beefy red, with sparing of the ear canals and ear lobes. Treatment is with systemic steroids and salicylates. Referral to an immunologist or rheumatologist may be indicated. Temporal bone fractures These may be the result of head injury. The direction and force of the impact often determine the alignment of fracture (longitudinal, transverse, mixed or obtuse). The clinical picture may include bloody ear discharge, haemotympanum, hearing loss and facial palsy. Online resources Hawke Library: www.hawkelibrary.com ■ Otolaryngology Houston: www.ghorayeb.com ■ The Ohio State University College of Medicine: www.medicine.osu.edu ■ Relapsing polychondritis This is an episodic, recurring inflammatory disorder affecting auricular cartilage. Scleral involvement may present as a visual impairment. Other areas that may be AD_HTT_025_032___APR13_07 4/4/07 4:10 PM Page 32 How to treat – external ear conditions GP’s contribution traindicated, because the patient has marked pain, and coexisting tympanic membrane perforation has not been excluded. A swab can be taken for culture to confirm the diagnosis. I would prescribe adequate analgesia and start ototopical ciprofloxacin (Ciloxan 0.3%), 3-4 drops bd. Cipro-HC drops (three drops bd) are also effective if the tympanic membrane is intact. The ear should be kept strictly dry. Poor clinical response at 48 hours would be an indication for review at a tertiary hospital. of a paper tissue. The right ear canal and drum look normal. All the local ENT practices are closed until mid-January at the earliest, and the local hospital has no ENT surgeon on call. DR ROSS WHITE Questions for the author Beecroft, NSW Case study JUST after Christmas, Michael, 12, presented with a painful left ear of two days’ duration. He had been away at a relative’s farm and had swum in a dam with his cousins. He has a history of perforated eardrum with an acute middle-ear infection at age eight, but his mother cannot remember which ear. He is afebrile, the tragus is very tender, and moving the pinna causes a lot of pain. The canal is filled with loose lightcoloured debris and there is a small amount of yellowish discharge. The ear is too tender to remove any of the material, even with a twist of a corner Should any attempt be made to syringe this ear or should Michael be referred to a tertiary hospital for ear toilet and management? My provisional diagnosis is acute diffuse bacterial otitis externa. The most likely organism is P aeruginosa. The features in the clinical history that support this diagnosis include rapid onset of pain and a history of swimming in a dam. Tenderness with tragal manipulation and the finding of debris without copious discharge also support the diagnosis. Acute otitis media is far less common in this age group. Ear syringing is con- Would oral flucloxacillin and topical ciprofloxacin be worth starting without any ear toilet? Topical ciprofloxacin provides excellent coverage for S aureus as well as other Gram-positive and Gram-negative bacteria. Adjuvant oral antibiotics might be considered for disease spread into How to Treat Quiz INSTRUCTIONS External ear conditions — 13 April 2007 FAX BACK Photocopy form and fax to (02) 9422 2844 1. With respect to the external ear canal, which TWO of the following are correct? ❏ a) The lateral (cartilaginous) portion of the external ear canal has tightly adherent skin that produces no wax ❏ b) The external ear is innervated by the greater auricular nerve as well as cranial nerves V, VII, IX and X ❏ c) The auricular cartilage is continuous with the lateral one-third of the external ear canal ❏ d) The epithelium of the lateral tympanic membrane moves medially to the middle ear space 2. Soft brown wax in the external ear canal of Caucasians and dark-skinned people helps maintain external ear health in which TWO ways? ❏ a) Immunoglobulins in the wax, with other constituents such as lysozymes, act in association with an intact skin epithelium to protect the external ear from infection ❏ b) The pH of healthy wax (4-5) discourages bacterial and fungal pathogens ❏ c) More acidic wax in people with diabetes (pH 3-4) provides extra infection protection ❏ d) When infection is present in the external ear canal increased wax production helps fight infection 3. With respect to foreign bodies and obstruction of the external ear canal, which THREE of the following are true? ❏ a) Exostoses can cause conductive hear- ing loss through obstruction with keratin and wax and direct contact with the lateral surface of the tympanic membrane ❏ b) Live insects such as cockroaches may cause drum rupture ❏ c) Osteomata occur most commonly in the anterior-superior portion of the ear canal and rarely cause symptoms ❏ d) Ticks can be left for a period of two weeks and will eventually be expelled 4. Jeffrey, 58, presented to his GP complaining of pain in the right ear. On examination his right external ear canal was very inflamed and tender. Jeffrey has a history of seborrhoeic dermatitis and has just returned from a surfing safari in Bali. Which TWO of the following are the most likely diagnosis? ❏ a) Infective otitis externa ❏ b) Otitis media with effusion ❏ c) Chronic suppurative otitis media ❏ d) Fungal otitis externa (otomycosis) 5. Jeffrey is treated with antibiotic ear drops but over the next 24 hours develops facial pain and sensitivity of the skull and scalp on the right side of his head. His wife finds small “scabs” on his pinna and in the external ear canal. Which THREE of the following would support a diagnosis of herpes zoster oticus (Ramsay Hunt syndrome)? ❏ a) Mastoid pain ❏ b) Decreased taste sensation on the right peri-auricular tissues. Are there any concerns about aural ciprofloxacin on the development of the middle-ear ossicles and the ossicular joints in young children with perforated tympanic membranes? Oral administration of ciprofloxacin and other quinolones has been shown to cause arthropathy in immature animals. There is no evidence that otic dosing has any effect on weight-bearing joints or ossicular structures. Topical ciprofloxacin is indicated for chronic suppurative otitis media or open tympanic cavity in adults and children aged one month or older. General questions for the author For the removal of cerumen, are electronic ear irrigators (eg, ‘Propulse’ or ‘Otoscillo’) any safer than a standard metal ear syringe? Electronic ear irrigators allow pressure-controlled warm-water irrigation of the ear canal to remove cerumen, which the manufacturer states is the main advantage over traditional metal syringes. They should only be used by experienced doctors, audiologists or nurses, and the same contraindications apply. How should a GP distinguish keratosis obturans from a cholesteatoma of the external auditory canal? Keratosis obturans is essentially a keratin plug obstructing the ear canal. Pressure on the bony ear canal can lead to erosion or smooth widening of the ear canal. Bilateral presentation can occur and is more commonly found in younger patients. External canal cholesteatoma involves bone erosion and periostitis. Unilateral presentation in an older age group is more common. Both conditions are best treated by ENT specialists. Complete this quiz to earn 2 CPD points and/or 1 PDP point by marking the correct answer(s) with an X on this form. Fill in your contact details and return to us by fax or free post. FREE POST How to Treat quiz Reply Paid 60416 Chatswood DC NSW 2067 side of his mouth and tongue ❏ c) Hearing loss and tinnitus ❏ d) Drooping of the right side of his mouth but normal movement of the upper face, including the forehead and muscles around the eye 6. Treatment of Ramsay Hunt syndrome can include which THREE of the following? ❏ a) Patching and eye protection if there is incomplete eyelid closure ❏ b) Antiviral medication such as valaciclovir or famciclovir ❏ c) Urgent grommet insertion to minimise hearing loss ❏ d) Oral steroids 7. Features of history, examination and investigation that help differentiate otitis externa from acute otitis media include which THREE of the following? ❏ a) A recent history of a lot of swimming ❏ b) The appearance of the tympanic membrane ❏ c) The season — acute otitis media is more common in summer, and otitis externa in winter ❏ d) Microbiological findings on ear swab 8. Which THREE of the following are recommended in the management of acute otitis externa? ❏ a) Topical antibiotics ❏ b) Oral steroids ❏ c) Avoidance of aminoglycoside or alcohol ONLINE www.australiandoctor.com.au/cpd/ for immediate feedback drops if the tympanic membrane is perforated ❏ d) The use of an otowick if canal oedema prevents adequate delivery of drops 9. Julian, 74, has diabetes and difficulty using his hearing aid because of ear wax. Three days after using a cotton bud in his ear he presents to you with severe pain in his ear. Which TWO features would suggest that his ear pain is due to malignant necrotising otitis externa? ❏ a) Antibiotic drops prescribed two days ago by another doctor have made no difference to his symptoms ❏ b) His age and diabetes ❏ c) On examination, an area of granulation tissue adjacent to the ear drum ❏ d) Vesicles in his conchal bowl 10. Aware that, in a patient such as Julian, this may be malignant necrotising otitis externa you refer him urgently to an ENT surgeon. With respect to his management and prognosis, which TWO of the following are true? ❏ a) Even if treated early, this problem has a mortality rate of 80% ❏ b) Treatment requires IV and prolonged antibiotics ❏ c) Hyperbaric oxygen therapy has achieved good results in some centres ❏ d) Resolution of abnormalities on technetium bone scan occur early when appropriate treatment is introduced, and is a good gauge of clinical success CONTACT DETAILS Dr: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Phone: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-mail: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RACGP QA & CPD No: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .and /or ACRRM membership No: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Address: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Postcode: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HOW TO TREAT Editor: Dr Martine Walker Co-ordinator: Julian McAllan Quiz: Dr Martine Walker The mark required to obtain points is 80%. Please note that some questions have more than one correct answer. Your CPD activity will be updated on your RACGP records every January, April, July and October. NEXT WEEK Available evidence continues to suggest considerable room for improvement in the recognition, treatment and control of hypertension in the primary care setting. But not all cases are straightforward. The next How to Treat looks at the more difficult cases of resistant hypertension. The author is Professor David W Johnson, director of nephrology and chair of medicine, Princess Alexandra Hospital, Brisbane; professor of medicine, University of Queensland, St Lucia, Brisbane, Queensland. 32 | Australian Doctor | 13 April 2007 www.australiandoctor.com.au