g logo nice orange

Overview

This summary has been developed for use by GPs and therefore only covers the information relevant to this setting. Please refer to the full guideline for the complete set of recommendations. For recommendations applicable to the community pharmacy setting, view our summary here

This summary includes:

  • prognosis
  • diagnosis
  • differential diagnosis
  • assessment
  • management
  • topical treatments
  • follow up.

This summary has been abridged for print. View the full summary at guidelines.co.uk/455656.article

What is otitis externa?

  • Otitis externa is inflammation of the external ear canal
    • localised otitis externa—is a folliculitis (infection of a hair follicle) that can progress to become a furuncle (boil) in the ear canal
    • diffuse otitis externa (also known as swimmer’s ear, or tropical ear)—is widespread inflammation of the skin and subdermis of the external ear canal, which can extend to the external ear and the tympanic membrane (ear drum)
    • otitis externa is defined as:
      • acute if it has lasted for 3 weeks or less
      • chronic if it has lasted for longer than 3 months
    • malignant otitis externa—is an aggressive infection that predominantly affects people who are immunocompromised, or have diabetes mellitus, or the elderly. Otitis externa spreads into the bone surrounding the ear canal (the mastoid and temporal bones). It is also known as necrotising otitis.

What is the prognosis for people with otitis externa?

  • Acute diffuse otitis externa:
    • symptoms of acute otitis externa usually improve within 48–72 hours of initiation of treatment
    • between 65–90% of patients with uncomplicated diffuse otitis externa have clinical resolution within 7 to 10 days, regardless of the topical medicine used
  • Localised otitis externa:
    • folliculitis may heal on its own after an initial period of itching and pain, or
    • it may develop into a pustule (i.e. furuncle) with increasing discomfort, which, without treatment, will burst, drain, and finally heal
  • Chronic otitis externa:
    • the lumen of the ear canal progressively narrows, and after several years, may become completely stenosed, resulting in deafness in the affected ear
  • Malignant otitis:
    • without treatment, this can be a fatal condition—osteomyelitis will progressively involve the mastoid, temporal, and basal skull bones, and the infection will spread to cerebrospinal fluid causing meningitis
    • with treatment, the mortality rate is less than 15%.

Diagnosis

What are the signs and symptoms of otitis externa?

  • Signs:
    • the ear canal or external ear, or both, are red, swollen, or eczematous with shedding of the scaly skin
    • swelling in the ear canal is typical of an early presentation of localised otitis externa; later the swelling has a white or yellow centre filled with pus; occasionally this progresses and the swelling eventually completely occludes the ear canal
    • discharge (serous or purulent) may be present in the ear canal
    • inflamed eardrum, which may be difficult to visualise if the ear canal is narrowed or filled with debris
  • Symptoms include any combination of the following:
    • itch (typical)
    • severe ear pain, disproportionate to the size of the lesion (typical)
    • pain made worse when the tragus or pinna is moved, or when an otoscope is inserted (typical)
    • tenderness on moving the jaw
    • tender regional lymphadenitis—may be present (less common)
    • sudden relief of pain if the furuncle in localised otitis externa bursts (rare)
    • loss of hearing if there is sufficient swelling to occlude the ear canal (rare).

What are the signs and symptoms of chronic otitis externa?

  • Signs:
    • lack of earwax in the external ear canal.
    • dry hypertrophic skin, which varies in thickness but often results in at least partial canal stenosis.
    • pain on manipulation of the external ear canal and auricle
  • Symptoms:
    • constant itch in the ear
    • mild discomfort
    • pain, if present, is usually mild.

What are the signs and symptoms of malignant otitis?

  • Signs:
    • granulation tissue at bone–cartilage junction of ear canal; exposed bone in the ear canal
    • facial nerve palsy (drooping face on the side of the lesion)
    • temperature over 39°C
  • Symptoms:
    • pain and headache, more severe than clinical signs would suggest
    • vertigo
    • profound hearing loss.

What else might it be?

  • The differential diagnosis of otitis externa includes:
    • acute otitis media—otitis externa can be secondary to otorrhoea from otitis media, particularly common in younger children, especially if they have had ventilation tubes (grommets) inserted in the tympanic membrane
    • foreign body in the ear—particularly in children
    • impacted earwax—may cause pain and deafness
    • cholesteatoma—eroding epithelial tissue in the middle ear and mastoid, with discharge in the ear canal
    • mastoiditis—if the person feels very unwell, or has a high temperature or marked hearing loss, or there is mastoid tenderness or swelling
    • malignant otitis
    • neoplasm—if there is a swelling in the ear canal that bleeds easily on contact. Compared with localised otitis externa, there is less pain and the onset is slower
    • referred pain—may originate from the sphenoidal sinus, teeth, neck, or throat
    • Ramsay Hunt syndrome—a form of herpes zoster affecting the facial nerve, associated with facial paralysis and loss of taste, which can also produce pain in the ear and other areas supplied by the nerve 
    • barotrauma—consider this in people who are divers, have recently travelled by air, or have received a blow to the ear
    • skin conditions—seborrhoeic dermatitis, atopic dermatitis, dermatophytosis, psoriasis, acne, herpes simplex, herpes zoster, lupus erythematosus. These may be risk factors, or the underlying cause of otitis externa.

Localised otitis externa

How should I manage someone with localised otitis externa?

  • Treat the pain if present:
    • treat with an analgesic and the application of local heat (for example a warm flannel). These measures are sufficient for most cases of localised otitis externa as folliculitis is usually mild and self-limiting
  • Treat infection if necessary:
    • oral antibiotics are rarely indicated. 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 medical condition which is associated with increased risk of severe infection (such as diabetes mellitus, or compromised immunity)
    • if an oral antibiotic is required, consider are a 7-day course of flucloxacillin, or clarithromycin (if the person is allergic to penicillin)
  • 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
  • Provide appropriate self-care advice to aid recovery and to reduce the risk of future infection.

What follow up is required for people with localised otitis externa?

  • Follow up is not normally necessary for acute localised otitis externa, as it is usually mild and self-limiting. However, consider follow up if:
    • an oral antibiotic has been prescribed
    • the person has underlying medical conditions, such as diabetes mellitus, or if they are immunocompromised.

When should I refer, or seek specialist advice, for someone with localised 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.

Acute diffuse otitis externa

How should I assess someone for acute otitis externa?

  • Take a clinical history and ask the person about the onset and nature of symptoms, including the:
    • severity of symptoms:
      • pain or tenderness on moving the ear (tragus or pinna) or jaw
      • itch
      • hearing loss
      • ear discharge
    • severity of inflammation—inflammation is more likely to be severe if there are any of the following:
      • fever
      • cellulitis spreading beyond the ear
      • regional lymphadenopathy
      • discharge (serous or purulent)
      • hearing loss (conductive)
      • red, oedematous ear canal narrowed and obscured by debris
  • Examine the ear canal, tympanic membrane, the aurical and cervical nodes
    • it can be difficult to adequately visualize the tympanic membrane in people with otitis externa. However, perforation can be assumed if the person:
      • has had a tympanostomy tube inserted in the past 12 months and there is no documentation of extrusion and closure of the tympanic membrane
      • can blow air out of the ear when the nose is pinched, or
      • can taste medication placed in the ear
  • Examine the surrounding tissue for dermaotological conditions
  • Identify any potential causes of otitis externa, such as:
    • radiotherapy to the ear, neck or head
    • previous ear surgery, such as tympanostomy
    • previous topical treatments for otitis externa or otitis media
    • atopic, allergic, or irritant dermatitis
    • dermatoses
    • trauma to ear canal from cleaning, scratching, or instrumentation
    • use of hearing aid or ear plugs
    • exposure to water or humid climate 
    • diabetes, immunosuppression, and older age
  • Consider the need for investigations—these are rarely useful, however, if treatment fails or otitis externa recurs frequently, consider taking an ear swab to determine the causative organism. Additionally, tympanometry, if available, can help show that the tympanic membrane is intact.

For information on taking ear swabs, view the full summary at guidelines.co.uk/455656.article

When should I take an ear swab from someone with otitis externa?

  • Consider taking an ear swab to determine the causative organism if:
    • treatment fails
    • otitis externa is recurrent or chronic
    • topical treatment cannot be delivered effectively (for example, if the ear canal is occluded due to swelling or debris)
    • the infection has spread beyond the external auditory canal
    • the condition is severe enough to require oral antibiotics
  • Take a swab from the medial aspect of the ear canal under visualization to reduce contamination.

Interpreting ear swab results 

  • Distinguishing a fungal infection from a bacterial infection, can be of therapeutic significance. However, interpretation of culture results is difficult, because:
    • 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 whether the identified 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.

How should I manage someone with acute otitis externa?

  • Manage any aggravating or precipitating factors
  • Consider cleaning the external auditory ear canal if earwax or debris obstructs the application of topical medication (this may require referral to an ear, nose and throat [ENT] specialist)
  • Prescribe or recommend an analgesic for symptomatic relief, if required
  • Consider prescribing a topical antibiotic with or without a topical corticosteroid—see Available preparations
    • there is no evidence to suggest which product is more effective, so factors such as the person’s preference, risk of adverse effects, cost, dosing frequency, and status of the eardrum should be taken into account
      • advise the person to use the preparation for a minimum of 7 days, but if symptoms persist to continue using it until they resolve, up to a maximum of 14 days.
    • adverse effects to consider include aminoglycoside-induced ototoxicity in people with a perforated tympanic membrane, aminoglycoside-induced skin sensitization, and fungal superinfection (particularly with long-term use). See Contraindications for more information
    • quinolone containing preparations (for example ciprofloxacin, or ofloxacin) only require twice daily dosing, and can be used in people with a perforated ear drum
    • topical acetic acid 2% spray is also a safe and effective treatment and can be used for mild cases
  • Consider inserting an ear wick if there is extensive swelling of the auditory canal (this may require ENT referral)
  • Oral antibiotics are rarely indicated 
For further information, refer to the full online summary at guidelines.co.uk/455656.article
    • consider seeking specialist advice if an oral antibiotics is thought to be required, including:
      • cellulitis extending beyond the external ear canal
      • when the ear canal is occluded by swelling and debris, and a wick cannot be inserted
      • people with diabetes or compromised immunity, and severe infection or high risk of severe infection, for example with Pseudomonas aeruginosa
  • If an oral antibiotic is to be prescribed in primary care, consider prescribing a 7-day course of flucloxacillin, or clarithromycin (if the person is allergic to penicillin)
  • Provide appropriate self-care advice to aid recovery and to reduce risk of future infection.
  • Topical treatments
    • there is evidence that topical treatments are effective, but there is insufficient evidence to recommend any antibiotic or corticosteroid preparation, or combination, over any other topical treatment on the basis of effectiveness
      • 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
      • topical acetic acid is an effective treatment and is comparable with antibiotic/steroid at week one. However, when treatment is extended beyond this, it is less effective
      • CKS does not recommend chloramphenicol ear drops, as they contain propylene glycol which causes contact dermatitis in about 10% of people.

For information on cleaning the external auditory canal in someone with acute diffuse otitis externa, view the full summary at guidelines.co.uk/455656.article

What methods should I consider for cleaning the external auditory canal in someone with acute diffuse otitis externa?

  • The following methods can be used to clean the ear canal to enable topical treatments to be applied effectively:
    • syringing or irrigation—to remove debris, provided that the tympanic membrane is intact
    • dry swabbing—to gently mop out thin secretions from the external auditory canal
    • microsuction—if irrigation and swabbing are ineffective or inappropriate. This usual requires referral to secondary care.

What self-care advice should I give someone with acute diffuse otitis externa?

  • Give the following self-care advice to people with otitis externa to aid recovery and reduce the risk of future infection:
    • avoid damage to the external ear canal:
      • if earwax is a problem, the person should seek professional advice and have it removed safely to avoid damaging the ear canal
      • cotton buds or other objects should not be used to clean the ear canal.
    • keep the ears clean and dry by:
      • using ear plugs and or a tight fighting cap when swimming—people with acute otitis externa should abstain from water sports for at least 7–10 days
      • using a hair dryer (at the lowest heat setting) to dry the ear canal after hair washing, bathing, or swimming
      • keeping shampoo, soap, and water out of the ear when bathing and showering
    • ensure skin conditions that are associated with the development of otitis externa are well controlled:
      • if the person is allergic or sensitive to ear plugs, hearing aids, or earrings, they should avoid them, or use alternatives if (for example hypoallergenic hearing aids are available)
      • if the person has a chronic skin condition (for example eczema or psoriasis), they should ensure that this is well controlled if possible
    • consider using acidifying ear drops or spray (such as EarCalm®) shortly before swimming, after swimming, and at bedtime. These ear drops are available to purchase over the counter at pharmacies.

What follow up is required for people with acute diffuse otitis externa?

  • Follow up in primary care is not normally necessary if the tympanic membrane has been visualised to rule out an underlying condition and symptoms have fully settled. However, consider follow up for people:
    • with severe otitis externa and accompanying cellulitis which has spread outside the auditory canal
    • with diabetes mellitus
    • who are immunocompromised
    • who have wax accumulation or who have narrow ear canals.

For information on treatment failure, view the full summary at guidelines.co.uk/455656.article

How should I manage treatment failure in people with acute diffuse otitis externa?

  • Review the diagnosis and exclude and manage other conditions
  • Check compliance with medication and self-care advice:
    • 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 the affected area:
    • 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
  • Prescribe a 7-day course of an oral antibiotic, (for example, flucloxacillin, or clarithromycin), if there are signs of systemic infection, or if the infection is spreading outside the ear canal
  • If these measures have been tried or are not applicable, consider the following options:
    • take an ear swab to identify the causative organism and tailoring treatment accordingly
    • seek specialist advice.

When should I refer, or seek specialist advice, for someone with acute diffuse otitis externa?

  • Refer urgently if malignant otitis is suspected. Suspect malignant otitis if:
    • there is unremitting pain, otorrhoea, fever or malaise
    • there is granulation tissue at the bone-cartilage junction of the ear canal, or exposed bone in the ear canal
    • the facial nerve is paralysed (drooping of the face on the side of the lesion)
    • raised temperature—over 39°C
  • Consider seeking specialist advice if:
    • symptoms have not improved despite treatment and treatment failure is unexplained
    • cellulitis is extensive
    • pain or discomfort is extreme
    • there is a considerable amount of discharge, or extensive swelling of the auditory canal, and microsuction or ear wick insertion is required.

Chronic diffuse otitis externa

How should I assess someone with chronic otitis externa?

  • Assess people with chronic otitis externa as for people with acute otitis externa. However, in addition, assess for:
    • severity of itching (usually the most prominent symptom) and signs of scratching
    • signs of fungal infection in the ear canal—whitish cotton-like strands of Candida, or small black or white balls of Aspergillus
    • signs of generalised dermatitis—mild erythema and lichenification (thickening of the skin) in the ear canal, and signs of underlying disease elsewhere (for example 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 eczematisation) reaction—id reactions can result from an infection or inflammatory skin condition
      • a fungal infection elsewhere in the body (for example skin, nails, vagina) can cause a secondary inflammatory process in the external ear canal (presents as an itchy rash with blisters or vesicles).

How should I manage someone with chronic otitis externa?

  • Management of chronic otitis externa may be difficult and may require trials of more than one strategy
  • Advise the person to avoid any potential causes of otitis externa
  • If fungal infection is suspected (signs of fungal growth in the ear canal):
    • prescribe a topical antifungal preparation. For mild-to-moderate and uncomplicated fungal infections, consider one of the following options:
      • clotrimazole 1% solution
      • acetic acid 2% spray (unlicensed use)
      • clioquinol and a corticosteroid (for example Locorten–Vioform®).
    • seek specialist advice if there is inadequate response
  • If the cause is:
    • irritant, or allergic dermatitis—advise the person to avoid contact with the irritant or allergen, and prescribe a topical corticosteroid
    • 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:
      • continue the corticosteroid treatment. However, reduce the potency of the corticosteroid and/or the frequency of application to the minimum required to maintain control
    • if the response is inadequate, consider a trial of a topical antifungal preparation
    • if treatment needs to be continued beyond 2 or 3 months, seek specialist advice.
  • Reinforce self-care advice, such as avoiding damage to the external ear canal and keeping the ears clean and dry.

When should I refer, or seek specialist medical advice, for someone with chronic otitis externa?

  • Consider referral to a specialist when:
    • otitis externa does not respond to appropriate treatment in primary care
    • contact sensitivity is suspected—patch testing would be useful to guide further management
    • the ear canal is occluded or is becoming occluded
    • malignant otitis is suspected.

What follow up is required for people with chronic otitis externa?

  • For people with chronic otitis externa:
    • review the response after completion of a course of treatment—people with diabetes mellitus or compromised immunity are at increased risk of complications (for example malignant otitis externa) and should be followed up more closely.

© NICE 2018. NICE CKS on otitis externa. Available from: cks.nice.org.uk/topics/otitis-externa/. All rights reserved. Subject to Notice of rights.

NICE guidance is prepared for the National Health Service in England. All NICE guidance is subject to regular review and may be updated or withdrawn. NICE accepts no responsibility for the use of its content in this product/publication.

Published date: February 2018.