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Acute Otitis Media

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Overview

Acute otitis media (AOM) is sudden-onset inflammation of the middle ear associated with effusion. It is usually due to an ear infection and is very common in children.

AOM often develops following a viral upper respiratory tract infection (URTI). This is thought to be due to disruption of the normal nasopharyngeal microbiome, allowing bacterial infection.

Subtypes

Otitis media is an umbrella term for pathologies affecting the middle ear. Its subtypes are:

  • Acute otitis media:
    • Acute inflammation of the middle ear usually due to bacterial or viral infection
  • Otitis media with effusion (glue ear):
    • Chronic inflammation of the middle ear with glue-like fluid in the middle ear behind the tympanic membrane
  • Chronic suppurative otitis media:
  • Mastoiditis:
    • Inflammation of the mastoid bone which can result from acute otitis media spreading
  • Cholesteatoma:
    • Keratinising squamous epithelium is present in the middle ear leading to malodourous discharge and conductive hearing losses

Epidemiology

  • Very common in children but less common in adults
  • Acute otitis media often occurs in the winter
  • Incidence is higher in children from birth to 4 years of age

Causes

The most common bacterial causes are:

  • Streptococcus pneumoniae
  • Haemophilus influenzae
  • Moraxella catarrhalis
  • Streptococcus pyogenes

Viral causes may be:

  • Respiratory syncytial virus
  • Rhinovirus
  • Adenovirus
  • Influenza
  • Parainfluenza

Risk Factors

Presentation

The main presenting complaint is an earache. Features are usually acute in onset and may be:

  • Non-specific features in children e.g. fever, crying, ear-tugging/rubbing/holding
  • Hearing loss
  • Features suggesting a middle ear effusion may be seen. These are necessary for a diagnosis of AOM to be made:
    • A bulging tympanic membrane
    • Decreased mobility with pneumatic otoscopy
    • Otorrhoea
  • Other otoscopy findings include:
    • A red, yellow, or cloudy tympanic membrane
    • Perforation of the tympanic membrane and/or discharge seen in the external auditory canal

Differential Diagnoses

Otitis media with effusion (glue ear)

  • Fluid in the middle ear in the absence of signs/symptoms of an infection
  • Effusion is seen with an air-fluid level/bubbles behind a normal tympanic membrane
  • Patients usually present with conductive hearing loss

Chronic suppurative otitis media

  • Persisting inflammation and draining discharge for >2 weeks
  • The tympanic membrane is usually perforated
  • No fever or ear otalgia

Otitis externa

  • There is no fluid in the middle ear
  • The tympanic membrane is not bulging
  • There may be tenderness of the tragus and pinna – movement is usually painful

Investigations

All patients

  • None – diagnosis is usually clinical
  • Consider immediate referral if:
    • Severe systemic infection
    • Suspected complications e.g. meningitis/mastoiditis/facial nerve palsy
    • Children <3 months of age with a fever of 38°C or more

Management

Stable patients

  • 1st-line: analgesia and support – patients should seek help if symptoms worsen or do not improve after 3 days

Antibiotic indications

Give immediate antibiotic prescriptions to the following patients if they do not need hospital admission:

  • Systemically very unwell
  • Signs/symptoms of serious illness
  • High risk of complications
  • Immunosuppression
  • Cystic fibrosis
  • Young and premature children
  • Tympanic membrane perforation

Antibiotic options are:

  • 1st-line: 5-7 days amoxicillin
  • If allergic: clarithromycin or erythromycin

Perforated Tympanic Membrane

  • 1st-line: no treatment + avoid getting water in the ear
    • Usually heals within 6-8 weeks
    • Give antibiotics if the perforated tympanic membrane follows acute otitis media
    • Consider myringoplasty

Monitoring

  • Patients taking antibiotics should have their symptoms reviewed within 7 days or if symptoms worsen. Alternate diagnoses or complications should be considered in these patients and explored.

Patient Advice

  • Patients should be advised that acute otitis media usually resolves within 3 days but may last up to a week. If symptoms worsen or do not resolve after 3 days, patients should seek medical help.
  • Patients should be safety-netted on the signs and symptoms of more severe infection and should seek medical help should they arise
  • Children can continue going to school once the fever is gone and the child is feeling better
  • Patients should avoid swimming if the tympanic membrane has perforated
  • Patients should avoid smoking and smoking both in and out of the house should be avoided in children

Complications

  • Recurring otitis media with effusion
  • Recurrence of infection
  • Temporary conductive hearing loss
  • Tympanic membrane perforation
  • Mastoiditis
  • Meningitis
  • Brain abscesses
  • Facial nerve paralysis

Prognosis

  • Most patients improve within 3 days but symptoms may last up to a week

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