General Measures

• Keep ear canal dry and free of debris and discharge while avoiding injuring it.
• Relieve itch and pain.
• Remove any precipitating antigens or irritants (such topical aminoglycoside), or devices (such as ear plugs, hearing aids, or ear rings).
• Treat any underlying skin condition such as seborrhoeic dermatitis, eczema, psoriasis.

Acute localised otitis externa

• Treat pain with an analgesic and the application of local heat (e.g. a warm flannel).
• Only consider an oral antibiotic for people with severe infection, or at high risk for severe infection.
• If pus is causing severe pain and swelling, consider incision and drainage (usually requires referral).

Acute diffuse otitis externa

• Treat any underlying skin condition such as eczema or psoriasis.
• Offer analgesics (e.g. paracetamol or ibuprofen) for pain.
• Treat with a topical ear preparation — there is insufficient evidence to prefer one preparation over another.
• Consider specialist referral for cleaning (microsuction) and/or insertion of an ear wick if these are necessary for severe infection.

Chronic otitis externa

• Treat any evidence cause (e.g. contact dermatitis, seborrhoeic dermatitis).
• If no cause is evident (as is the usual case):
• Treat with a 7-day course of a topical preparation containing only a corticosteroid without antibiotic; consider an acetic acid spray at the same time.
• If there is an adequate response, treatment may need to be continued for 2–3 months.
• If the response is inadequate, consider a topical antifungal.
• Consider specialist referral when:
• Otitis externa does not respond to appropriate treatment in primary care.
• Contact sensitivity is suspected and patch testing would be useful to guide further management.
• The ear canal is occluded or becoming occluded.
• Malignant otitis is suspected.

• Confirm the diagnosis.
• Assess for the presence of precipitating and risk factors:
• Diabetes, immunosuppression, older age.
• Exposure to water, humid climate.
• Use of hearing aid, ear plugs.
• Trauma to ear canal from cleaning, scratching, instrumentation.
• Dermatoses.
• Atopic, allergic, or irritant dermatitis.
• Previous topical treatments for otitis externa or otitis media.
• Previous ear surgery, such as tympanostomy.
• Radiotherapy to ear.
• Assess severity of symptoms:
• Pain or tenderness on moving ear (tragus or pinna) or jaw.
• Itch.
• Hearing loss.
• Ear discharge.
• Assess impact on work, social life, and activities of daily living.
• Assess severity of inflammation:
• Inflammation is more likely to be severe if there any of the following:
• Ear canal is red, oedematous, narrowed, and obscured by debris.
• Hearing loss (conductive).
• Discharge, serous, or purulent.
• Regional lymphadenopathy.
• Cellulitis spreading beyond the ear.
• Fever.
• Assess need for investigations:
• Investigations are rarely useful. However, if treatment fails or otitis externa recurs frequently, consider taking an ear swab for bacterial and fungal microscopy and culture.
• Assess patency of tympanic membrane:
• It can be difficult to adequately visualize the tympanic membrane in people with otitis externa. However:
• Perforation can be assumed if the person:
• Can taste medication placed in the ear, or
• Can blow air out of the ear when the nose is pinched, or
• Has had a tympanostomy tube inserted in the past 12 months and there is no documentation of extrusion and closure of the tympanic membrane.
• Tympanometry, if available, can help show that the tympanic membrane is intact.

• CKS found no directly relevant evidence from clinical trials or systematic reviews.
• These recommendations are therefore pragmatic, and largely based on expert opinion in published guidelines and reviews [American Academy of Otolaryngology et al, 2006; Osguthorpe and Nielsen, 2006].

• Laboratory investigations are rarely useful.
• However, if treatment fails or otitis externa recurs frequently, consider taking an ear swab for bacterial and fungal microscopy and culture.

• A swab is best taken from the medial aspect of the ear canal under visualization to reduce contamination.
• Identifying the organism, and especially distinguishing a fungal infection from a bacterial infection, can be of therapeutic significance. However, interpretation of culture results is difficult:
• Reported bacterial susceptibility may not correlate with clinical outcomes because sensitivities are determined for systemic (not topical) administration. Much higher concentrations of antibiotic can be achieved with topical application.
• It is not possible to tell from the culture results whether the isolated organisms are causing the disease or are merely contaminants. In particular, there is likely to be a fungal overgrowth after using antibacterial drops as these will have suppressed the normal bacterial flora.

• These recommendations are pragmatic and based on expert opinion [Roland, 2001; Osguthorpe and Nielsen, 2006].
• Since virtually all of the bacteria recovered are sensitive to the high concentrations of antibiotic available in topical ear medications it is unnecessary to routinely culture the ears of people with acute otitis externa [Roland, Personal Communication, 2004].

• Remove or treat any precipitating or aggravating factors.
• Prescribe or recommend an analgesic for symptomatic relief.
• Paracetamol or ibuprofen are usually sufficient. Codeine can provide additional analgesia for severe pain.
• Treat inflammation using a topical ear preparation for 7 days:
• For mild cases (discomfort and/or pruritus; no pain, deafness, or discharge) topical acetic acid 2% spray can be used first-line.
• For more severe cases (pain, deafness, discharge), or if treatment with acetic acid for mild otitis externa is not effective, a topical antibiotic with or without a topical corticosteroid should be used:
• Topical preparation containing both a non-aminoglycoside antibiotic and a corticosteroid e.g. flumetasone–clioquinol (Locorten–Vioform^®) ear drops.
• Topical preparations containing both an aminoglycoside antibiotic and a corticosteroid.
• Topical preparations containing only an antibiotic.
• If there is sufficient earwax or debris to obstruct topical medication, consider cleaning the external auditory canal (may require referral).
• If there is extensive swelling of the auditory canal, consider inserting an ear wick (may require referral).
• Only consider adding an oral antibiotic for people with severe infection.
• Provide appropriate self-care advice to aid recovery and to reduce risk of future infection.

• Topical ear preparations:
• The decision about which topical ear preparation to prescribe should take into account the risk of adverse effects, the person's preference, and cost.
• Adverse effects to consider include aminoglycoside-induced ototoxicity in people with a perforated tympanic membrane, aminoglycoside-induced skin sensitization, and fungal superinfection (particularly with longer treatments).
• Ear wick:
• This is impregnated with the medication and is inserted into the auditory canal to aid drug delivery when the auditory canal is narrowed by swelling or debris.
• Insertion requires referral (unless the equipment and expertise are available locally).
• The ear wick should be changed at least every 2 or 3 days.
• Oral antibiotics are rarely indicated.
• Consider seeking specialist advice if an oral antibiotic is thought to be required, such as for:
• Cellulitis extending beyond the external ear canal.
• When the ear canal is occluded by swelling and debris, and a wick can not be inserted.
• Diabetes or compromised immunity, and severe infection or high risk of severe infection, e.g. with Pseudomonas aeruginosa.
• If an oral antibiotic is to be prescribed in primary care, the options to consider are a 7-day course of:
• Flucloxacillin, or
• Erythromycin, if the person is allergic to penicillin, or
• Clarithromycin, if the person can not tolerate erythromycin.

• These recommendations on the management of acute diffuse otitis externa are based on the evidence-based recommendations issued by the American Academy of Otolaryngology — Head and Neck Surgery Foundation [American Academy of Otolaryngology et al, 2006], published reviews [Sander, 2001; Block, 2005; Osguthorpe and Nielsen, 2006; DynaMed, 2007], the Aural discharge patient pathway issued by Centre for Change and Innovation for NHS Scotland [NHS Scotland, 2005], and the CKS review of the supporting evidence.
• Topical treatments:
• There is evidence that topical treatments are effective, but insufficient evidence to prefer any antibiotic or corticosteroid preparation, or combination, over any other topical treatment on the basis of effectiveness.
• There is evidence that topical corticosteroids are at least as effective as topical antibiotics combined with corticosteroids. However, because of methodological weaknesses in the clinical trials and because acute diffuse otitis externa is thought to be caused by an infection, topical corticosteroids on their own are not generally recommended as first-line treatment [American Academy of Otolaryngology et al, 2006; BNF 53, 2007].
• There is evidence that topical aminoglycosides are ototoxic and may damage the inner ear, and they are therefore contraindicated if the tympanic membrane is perforated [CSM, 1997].
• Topical aminoglycosides are less preferred by some experts because they can cause contact dermatitis, although this is rare after a short course for acute otitis externa [American Academy of Otolaryngology et al, 2006].
• Chloramphenicol ear drops are not recommended because they cause contact dermatitis in about 10% of people [BNF 53, 2007].
• Clioquinol is antibacterial and antifungal and has lower risks of skin reactions and ototoxicity than aminoglycosides. Therefore, on theoretical grounds, the combination flumetasone–clioquinol (Locorten–Vioform^®) ear drops might be slightly preferred over preparations containing aminoglycosides — CKS found no direct evidence from comparative trials to support this.
• Fluoroquinolone antibiotic ear drops (ciprofloxacin and ofloxacin) are unlicensed and only available on a named-patient basis. They might be initiated in secondary care for resistant cases of pseudomonal infection. The use of fluoroquinolone eye drops in the ear is an unlicensed indication [BNF 53, 2007].
• The recommendation to use topical acetic acid first line for mild cases of acute diffuse otitis externa, but antibiotic-corticosteroid combinations for more severe cases is based on feedback from CKS expert reviewers.
• There are no concerns with antibiotic resistance or fungal overgrowth with acetic acid, and the limited evidence available suggests that it has some efficacy, although this may not be as great as with an antibiotic-corticosteroid combination.
• Analgesia:
• CKS found no trials of analgesics used specifically for otitis externa, but they are widely used, and are recommended by experts [American Academy of Otolaryngology et al, 2006].
• Oral antibiotics:
• CKS found no direct evidence from placebo-controlled trials, and no relevant evidence from clinical trials of adding oral antibiotics to topical treatment.
• These recommendations are therefore based on guidelines on the management of acute otitis externa [American Academy of Otolaryngology et al, 2006], and the general principles of management of staphylococcal skin infections [Hay and Adriaans, 2004].
• Otitis externa with furunculosis or spreading cellulitis is thought to be usually due to staphylococcal infection, as with furunculosis and cellulitis in other anatomical locations [Hay and Adriaans, 2004]. Although CKS found no evidence from clinical studies to support this assumption, it seems plausible.
• Flucloxacillin has a narrow spectrum of activity, and is active against most susceptible Gram-positive cocci, including beta-lactamase-producing staphylococci and streptococci. However, it is not active against MRSA (meticillin-resistant Staphylococcus aureus). It diffuses well into most tissues, so is suitable for skin and soft tissue infections [Finch et al, 2003].
• Erythromycin and clarithromycin have a broad spectrum of activity and are active against most sensitive Gram-positive cocci (including staphylococci and streptococci) and some Gram-negative cocci and anaerobes [Finch et al, 2003].
• Clarithromycin may be used in people who are known not to tolerate erythromycin. It is more effective against common pathogens than erythromycin, and has fewer gastrointestinal adverse effects [Finch et al, 2003]. However, it is markedly more expensive than erythromycin.
• Quinolones are not recommended for use in primary care because, if the person is thought to be at high risk for pseudomonal infection, they should be referred to a specialist.
• These recommendations may differ considerably from UK practice. In 1997, general practitioners prescribed oral antibiotics for 21% of first episodes of otitis externa. Amoxicillin/ampicillin was the most frequently prescribed antibiotic (34%) [Rowlands et al, 2001]. The authors did not discuss the appropriateness of the prescribing patterns. CKS was unable to find more recent data.

Consider one or more of the following methods for cleaning the ear canal to facilitate application and effectiveness of topical treatments:

• Gentle syringing or irrigation — to remove debris, provided that the tympanic membrane is intact — regarded as controversial by some experts.
• Dry swabbing — to gently mop out thin secretions from the external auditory canal.
• Microsuction — if irrigation and swabbing are ineffective or inappropriate. Microsuction will usually require referral to secondary care.

• Clearing the auditory canal of debris and discharge is thought to improve drug penetration and reduce the risk of future infections [American Academy of Otolaryngology et al, 2006]. However, CKS found no clinical trials of different cleaning methods in people with acute localized otitis externa.
• Irrigation, dry swabbing, and microsuction under direct vision, are commonly used methods of aural cleansing, and are recommended in a number of guidelines [Block, 2005; NHS Scotland, 2005; American Academy of Otolaryngology et al, 2006].
• Some experts recommend that irrigation is not attempted in people with otitis externa unless the tympanic membrane can be seen to be intact [Sander, 2001]. However, if cleaning is thought to be beneficial, the tympanic membrane is likely to be obscured. CKS therefore recommends that the integrity of the tympanic membrane be clinically assessed rather than referring all such cases to secondary care.
• Irrigation is thought by some experts to be unsafe in the elderly, in people with diabetes, and in people who are immunocompromised [American Academy of Otolaryngology et al, 2006].
• It has been suggested on the basis of a small case-control study (13 cases, 26 controls), [Rubin et al, 1990], and a case series [Zikk et al, 1991], that aural irrigation for impacted earwax might precipitate malignant otitis externa in elderly people with cutaneous hypoperfusion secondary to diabetic microangiopathy.
• The majority of people who get malignant otitis externa are immunocompromised, usually by diabetes mellitus [Grandis et al, 2004].
• CKS found only one case series that documented the circumstances under which malignant otitis externa developed. All six cases presented after weeks to months of treatments at primary care level with oral and local antibiotics [Sardesai and Krishnakumar, 2002].
• CKS found no reports of malignant otitis externa being associated with aural irrigation in people being treated for otitis externa. Aural irrigation for otitis externa is likely to be less traumatic than irrigation for impacted earwax because in otitis externa the purpose of irrigation is to remove soft debris from a tender ear canal, rather than impacted earwax.
• CKS therefore recommends that, if it seems to be the most practical method, aural irrigation be performed gently, and with extra caution in people at risk for malignant otitis externa, who should in any case be followed up closely.

• Advise the individual that they can reduce the risk of future episodes of otitis externa by:
• Avoiding damage to the external ear canal:
• If earwax is a problem, the person should seek professional advice about removing it without damaging the ear canal. (People with diabetes probably should not have their ears syringed to remove impacted earwax.)
• Cotton buds or other objects should not be used to clean the ear canal.
• Keeping the ears dry and clean by:
• Using ear plugs when swimming.
• Using a hair dryer (at the lowest heat setting) to dry the ear canal after hair washing.
• Keeping shampoo, soap, and water out of the ear when bathing and showering.
• Treating or avoiding more generalized skin conditions:
• If they are subject to allergies, the person may want to avoid ear drops containing neomycin.
• If allergic or sensitive to ear plugs, hearing aids, or earrings, the person should seek advice from a healthcare professional.
• If also suffering from another skin condition (e.g. eczema, psoriasis), the person should ensure that this is treated appropriately.
• Using acidifying ear drops or spray shortly before swimming, after swimming, at bedtime, or all of these. These ear drops are available over the counter.

• CKS found no randomized trials comparing the efficacy of different preventive strategies.
• These are therefore pragmatic recommendations based on expert opinion [American Academy of Otolaryngology et al, 2006].

• Consider follow up for people with:
• Severe otitis externa with accompanying cellulitis which has spread outside the auditory canal.
• Diabetes or compromised immunity.

• Most cases of otitis externa resolve within a few days of starting treatment, and thus do not need follow up.

• CKS found no relevant trials or guidelines. These recommendations are therefore pragmatic advice.
• Diabetes and compromised immunity are risk factors for malignant otitis. The threshold for follow up should therefore be lowered for people with acute diffuse otitis externa and these concomitant conditions.

• Admit urgently if malignant otitis is suspected.
• Consider seeking specialist advice if:
• Symptoms have not improved despite treatment and treatment failure is unexplained.
• Treatment with a quinolone is indicated.
• Consider referral to secondary care if there is:
• Extensive cellulitis.
• Extreme pain or discomfort.
• Considerable discharge or extensive swelling of the auditory canal, and microsuction or ear wick insertion is required.

• Suspect malignant otitis if:
• Pain and headache are more severe than the clinical signs would suggest, or
• There is granulation tissue at the bone–cartilage junction of the ear canal, or exposed bone in the ear canal, or
• The facial nerve is paralysed (drooping of the face on the side of the lesion).

• These are pragmatic recommendations based on current practice [NHS Scotland, 2005].

• Review the diagnosis and exclude and manage other conditions.
• Assess and manage ongoing triggers (e.g. exposing ears to moisture, trauma to the ear canal by attempts to clean or scratch it).
• Review compliance with medication.
• Reinforce advice on administering drops or ointment.
• Consider repeating treatment, or switching from a drop preparation to a spray or vice versa.
• Assess factors that would impede delivery of topical medication to affected areas.
• If there is extensive discharge, consider gentle irrigation (provided the tympanic membrane is intact), or microsuction (which might require referral).
• If there is extensive swelling of the auditory canal, consider referral for insertion of an ear wick or initiation of a systemic antibiotic.
• If contact dermatitis due to neomycin or other aminoglycoside is suspected:
• Consider switching to a preparation which does not contain an aminoglycoside — see Available preparations.
• Consider referral to a dermatologist for patch testing to confirm sensitivities.
• If there are systemic signs of infection, or if the infection is spreading outside the ear canal, prescribe a 7-day course of an oral antibiotic, (i.e. flucloxacillin; or erythromycin if penicillin sensitive; or clarithromycin if erythromycin and flucloxacillin are both contraindicated).
• If these measures have been tried, or are not applicable:
• Consider culturing a specimen of the ear canal to identify fungi and resistant bacteria.
• Consider the possibility of a fungal infection and treat with topical preparation containing an antifungal such as clotrimazole 1% ear drops (Canesten^®), or flumetasone pivalate 0.02%, clioquinol 1% ear drops (Locorten–Vioform^®).
• Otherwise seek specialist advice.

• These recommendations are pragmatic advice and largely based on expert opinion [American Academy of Otolaryngology et al, 2006].

• Assess for the presence of precipitating and risk factors, severity of symptoms and inflammation, and patency of tympanic membrane as for acute otitis externa.
• In particular, assess for:
• Severity of itching — usually the most prominent symptom — and signs of scratching.
• Signs of fungal infection on examining the ear canal — whitish cotton-like strands of Candida, small black or white balls of Aspergillus.
• Signs of generalized dermatitis — mild erythema and lichenification (thickening of the skin) in the ear canal, and signs of underlying disease elsewhere (e.g. seborrhoeic dermatitis, psoriasis).
• Evidence of contact allergy or sensitivity — use of ear plugs, hearing aid, earrings, sensitizing medications (topical and systemic).
• Evidence of a source for an id (auto eczematization) reaction — a focus of fungal infection elsewhere in the body (e.g. skin, nails, vagina) can cause a secondary inflammatory process in the external ear canal.

• These recommendations are pragmatic, and are based on expert opinion [Roland, 2001; Osguthorpe and Nielsen, 2006].

• Laboratory investigations are rarely useful.
• However, if the treatment strategy fails, consider taking an ear swab for bacterial and fungal microscopy and culture.

• A swab is best taken from the medial aspect of the ear canal under visualization to reduce contamination.
• Identifying the organism, and especially distinguishing a fungal from a bacterial infection, can be of therapeutic significance. However, interpretation of culture results is difficult:
• Reported bacterial susceptibility may not correlate with clinical outcomes because sensitivities are determined for systemic (not topical) administration. Much higher concentrations of antibiotic can be achieved with topical application.
• It is not possible to tell from the culture results whether the isolated organisms are causing the disease or are merely contaminants. In particular, there is likely to be a fungal overgrowth after using antibacterial drops as these will have suppressed the normal bacterial flora.

• These recommendations are pragmatic and based on expert opinion [Roland, 2001; Osguthorpe and Nielsen, 2006].

• Apply general measures, as for acute diffuse otitis externa. The aims are to: keep the ear canal dry and free of debris and discharge while avoiding injuring it; relieve itch and pain; remove any precipitating antigens or irritants; treat any underlying skin condition such as seborrhoeic dermatitis.
• Treatment may be difficult, and may require trials of more than one strategy.
• If fungal infection is suspected (signs of fungal growth in ear canal):
• Prescribe a topical antifungal preparation.
• Seek specialist advice if there is inadequate response.
• If the cause seems to be seborrhoeic dermatitis:
• Treat topically with an antifungal–corticosteroid combination.
• If no cause is evident:
• Prescribe a 7-day course of a topical preparation containing only a corticosteroid without antibiotic. Consider co-prescribing an acetic acid spray.
• If there is an adequate response:
• The corticosteroid treatment may need to be continued. Reduce the potency of the corticosteroid and/or the frequency of application to the minimum required to maintain control.
• If treatment cannot be withdrawn after 2 or 3 months, seek specialist advice.
• If the response is inadequate, consider a trial of a topical antifungal preparation.

• Avoid preparations containing ingredients that can cause an allergic or reactive dermatitis, such as aminoglycosides (which may all cross-react).
• For further information, see Contraindications.
• Topical antifungal preparations:
• For mild-to-moderate and uncomplicated fungal infections, treat either with:
• A topical antifungal: clotrimazole 1% solution.
• Acetic acid 2% spray (unlicensed use).
• A topical preparation containing clioquinol and a corticosteroid e.g. Locorten–Vioform^®.

• Because treatment strategies for chronic otitis externa have not been studied in clinical trials, these recommendations are pragmatic advice, largely based on expert opinion [Roland, 2001; Osguthorpe and Nielsen, 2006].
• Topical antifungal preparations:
• CKS is unable to find any randomized trials comparing the acetic acid 2% spray and a topical antifungal.
• Acetic acid 2% ear spray:
• Acidic preparations are thought to reduce the pH in the external auditory canal, thus restricting the growth of bacteria and fungal infections which flourish in an alkaline environment (pH 8–10) [Dohar, 2003].
• Acetic acid 2% ear spray (Earcalm^®) is only licensed for the treatment of superficial infections of the external auditory canal.
• Clioquinol can also be considered as it possesses antibacterial and antifungal activities [ABPI Medicines Compendium, 2007; BNF 53, 2007].

• Consider referral when:
• Otitis externa does not respond to appropriate treatment in primary care.
• Contact sensitivity is suspected and patch testing would be useful to guide further management.
• The ear canal is occluded or becoming occluded.
• Malignant otitis is suspected.

• These recommendations are pragmatic advice. CKS found no relevant trial evidence or guidelines.

• Review response after completion of a course of treatment.
• People with diabetes or compromised immunity are at increased risk for complications and should be followed up more closely.

• These recommendations are pragmatic advice. CKS found no relevant trial evidence or guidelines.

• Treat pain:
• Treat with an analgesic and the application of local heat (e.g. a warm flannel). These measures are sufficient for most cases of localized otitis externa as folliculitis is usually mild and self limiting.
• Treat infection if necessary:
• Only consider an oral antibiotic for people with severe infection, or at high risk for severe infection, for example if:
• Furunculosis or cellulitis spreads beyond the ear canal to the pinna, neck, or face.
• There are systemic signs of infection, such as fever.
• The person has a condition (e.g. poorly-controlled diabetes or compromised immunity) that is associated with increased risk of severe infection.
• Drain pus if necessary:
• If pus is causing severe pain and swelling, consider incision and drainage.
• This is rarely required.
• Incision and drainage usually requires referral, although a small pustule near the entrance to the ear canal may be drained by incising it with a surgical needle.
• Advise on ear hygiene:
• Minimize trauma to ear canal: no scratching with anything and no cleaning with cotton buds.

• Oral antibiotics are rarely indicated.
• If an oral antibiotic is to be prescribed in primary care, the options to consider are a 7-day course of:
• Flucloxacillin, or
• Erythromycin, if the person is allergic to penicillin, or
• Clarithromycin, if the person cannot tolerate erythromycin.

• CKS found no evidence or guidelines specifically on furunculosis in the external ear canal.
• These recommendations are therefore pragmatic advice, based on the most likely causative organism (Staphylococcus aureus) and expert opinion from the medical literature on how furunculosis should be treated [Laube, 2004; Sladden and Johnston, 2005; McNulty, Personal Communication, 2006].
• Oral antibiotics
• CKS found no direct evidence from placebo-controlled trials.
• These recommendations are therefore based on guidelines on the management of acute otitis externa [American Academy of Otolaryngology et al, 2006], and the general principles of management of staphylococcal skin infections [Hay and Adriaans, 2004].
• Otitis externa with furunculosis or spreading cellulitis is thought to be usually due to staphylococcal infection as with furunculosis and cellulitis in other anatomical locations [Hay and Adriaans, 2004]. Although CKS found no evidence from clinical studies to support this assumption, it seems plausible.
• Flucloxacillin has a narrow spectrum of activity, and is active against most susceptible Gram-positive cocci, including beta-lactamase-producing staphylococci and streptococci. However, it is not active against MRSA (meticillin-resistant Staphylococcus aureus). It diffuses well into most tissues, so is suitable for skin and soft tissue infections [Finch et al, 2003].
• Erythromycin and clarithromycin have a broad spectrum of activity and are active against most sensitive Gram-positive cocci (including staphylococci and streptococci) and some Gram-negative cocci and anaerobes [Finch et al, 2003].
• Clarithromycin may be used in people who are known not to tolerate erythromycin. It is more effective against common pathogens than erythromycin, and has fewer gastrointestinal adverse effects [Finch et al, 2003]. However, it is markedly more expensive than erythromycin.

• Follow up according to severity and risk.
• No follow up is necessary for most cases of localized otitis externa as they are mild and self limiting.
• Consider follow up if an antibiotic has been prescribed, or if there are risk factors such as insulin-dependent diabetes or compromised immunity.

• These are pragmatic recommendations as CKS found no evidence or guidelines on managing acute localized otitis externa.

• Consider referral to secondary care:
• If relief of pain and swelling requires incision and drainage of the furuncle, and the resources and skills are not available in primary care.
• If there is inadequate response to oral antibiotic treatment.
• If cellulitis is spreading outside the auditory canal.

• These recommendations are pragmatic advice as CKS was unable to find relevant evidence or guidelines.