Lucan · Conditions

Acute otitis media (paediatric)

Australian guidance: eTG Antibiotic — Acute Otitis Media + RACGP

1. Definition and epidemiology

Acute otitis media (AOM) is a rapid-onset bacterial or viral infection of the middle ear cleft, characterised by signs of acute inflammation and middle ear effusion. It is the most common reason antibiotics are prescribed to children in Australia. By age 3 years, approximately 80% of Australian children will have experienced at least one episode, with Aboriginal and Torres Strait Islander children experiencing a disproportionately high burden, including earlier onset, greater severity, and higher rates of chronic suppurative otitis media. Peak incidence is between 6 and 18 months of age.

2. Pathophysiology

The pathophysiology of AOM is described in Robbins Ch 16 Head and Neck and centres on the Eustachian tube and its relationship to the nasopharynx. In young children, the Eustachian tube is shorter, more horizontal, and has reduced stiffness compared with adults, making it vulnerable to dysfunction. Preceding viral upper respiratory tract infection causes nasopharyngeal mucosal oedema, impairing Eustachian tube ventilation and mucociliary clearance. Negative middle ear pressure follows, drawing nasopharyngeal secretions into the middle ear cleft. Bacterial colonisers of the nasopharynx, principally Streptococcus pneumoniae, non-typeable Haemophilus influenzae, and Moraxella catarrhalis, gain access and proliferate within the warm, fluid-rich environment. The resulting acute suppurative inflammation produces the hallmarks of bulging, erythematous, and opacified tympanic membrane, middle ear effusion, and otalgia. Spontaneous resolution occurs in approximately 60 to 80% of cases without antibiotics, reflecting the immunological capacity of the middle ear mucosa and the self-limiting nature of many viral precipitants. Biofilm formation by non-typeable H. influenzae and S. pneumoniae contributes to recurrence and treatment failure. Pneumococcal conjugate vaccination reduces the proportion of AOM caused by vaccine serotypes of S. pneumoniae, though non-typeable H. influenzae has proportionally increased as a causative pathogen following widespread vaccine uptake.

3. Clinical presentation and diagnostic criteria

The diagnosis of AOM requires three criteria to be met: acute onset of symptoms, presence of middle ear effusion, and signs of middle ear inflammation. Acute onset symptoms include otalgia (ear pulling or tugging in non-verbal children), irritability, fever, and disturbed sleep; onset is typically within 48 hours of a preceding viral upper respiratory tract infection. On otoscopic examination, middle ear effusion is inferred by one or more of bulging tympanic membrane, absent or reduced light reflex, opacification of the tympanic membrane, and visible air-fluid level or bubbles behind the membrane. Signs of inflammation include distinct erythema of the tympanic membrane beyond that attributable to crying or fever, and the presence of spontaneous otorrhoea through a tympanic membrane perforation. Acute otitis media with otorrhoea (AOMWO) indicates a perforated tympanic membrane with purulent discharge in the ear canal and carries the same treatment principles. Pneumatic otoscopy demonstrating reduced or absent tympanic membrane mobility is the most reliable sign of middle ear effusion and is recommended when available. Bilateral AOM and recurrent AOM (three or more episodes within 6 months, or four or more within 12 months) are clinically important subgroups requiring additional consideration.

4. Investigations and AU-specific cutoffs

AOM is a clinical diagnosis. No investigations are required in uncomplicated presentations. Tympanometry, when available, confirms middle ear effusion and aids distinction from otitis media with effusion (OME); a type B flat trace is consistent with effusion. Tympanocentesis with microbiological culture of middle ear fluid is not routinely performed in primary care but is indicated in children with AOM who are immunocompromised, have failed two or more antibiotic courses, or have AOM with mastoiditis. Full blood count, C-reactive protein, and blood cultures are indicated when the child appears systemically unwell or when complications are suspected. High-resolution computed tomography of the temporal bones and mastoids is the investigation of choice if mastoiditis or intracranial extension is suspected. Audiological assessment including pure-tone audiometry is recommended after three or more episodes within 12 months, or persistent effusion beyond 3 months, to quantify conductive hearing loss.

5. Management

eTG Antibiotic guidelines stratify management by age, severity, and Indigenous status. Children aged 2 years and over with non-severe uncomplicated AOM may be offered a 48 to 72 hour period of observation without antibiotics if the family is willing and reliable follow-up can be arranged; most will improve without treatment. Antibiotics are indicated immediately for all children aged under 6 months, children aged 6 months to 2 years with bilateral AOM or AOM with otorrhoea, children of any age with severe AOM (otalgia rated severe, fever above 39 degrees Celsius, or appearance of systemic illness), and all Aboriginal and Torres Strait Islander children aged under 2 years given the high risk of rapid progression and chronic suppurative otitis media in this population.

First-line treatment is amoxicillin at a weight-based dose of 50 mg/kg per day in two divided doses (maximum 1.5 g per day) for 5 days in children aged 2 years and over, or 10 days for children under 2 years and those with severe AOM. In Aboriginal and Torres Strait Islander children and those with recurrent AOM, amoxicillin-clavulanate 22.5 plus 3.2 mg/kg per dose twice daily (maximum amoxicillin component 875 mg twice daily) for 10 days is preferred as the first-line agent given the higher prevalence of beta-lactamase-producing H. influenzae and M. catarrhalis. If the child is penicillin-allergic without anaphylaxis, cefalexin 25 mg/kg twice daily (maximum 500 mg twice daily) is used. True penicillin anaphylaxis warrants specialist referral. Oral ibuprofen or paracetamol at appropriate weight-based doses is recommended for analgesia regardless of whether antibiotics are prescribed. Topical anaesthetic ear drops (e.g. choline salicylate/glycerin, Auralgan) may be used for pain if there is no perforation.

For AOMWO through a perforation, aural toilet followed by topical ciprofloxacin drops (Ciloxan) is recommended in addition to systemic amoxicillin-clavulanate. Topical aminoglycoside drops are contraindicated in the presence of a tympanic membrane perforation due to ototoxicity risk. Failure to improve after 48 to 72 hours of treatment warrants changing to amoxicillin-clavulanate if initial therapy was amoxicillin alone, or further assessment including tympanocentesis culture if already on combination therapy.

6. Pharmacology and AU PBS notes

Amoxicillin (Amoxil and generics) is listed on the Pharmaceutical Benefits Scheme (PBS) for acute bacterial infection; it is available as a 250 mg per 5 mL oral liquid and as 250 mg and 500 mg capsules. Amoxicillin-clavulanate (Augmentin Duo Forte paediatric 400 mg plus 57 mg per 5 mL) is PBS-listed for paediatric bacterial infections. When prescribed for AOM in Aboriginal and Torres Strait Islander children or in high-risk groups, clinicians should document the clinical justification for combination therapy. Ciprofloxacin 0.3% ear drops (Ciloxan) for topical use are PBS-listed for otitis externa and AOMWO. Cefalexin (Keflex and generics) is PBS-listed for bacterial infection in penicillin-allergic patients. There is no PBS streamlined restriction specific to AOM. Topical analgesic ear drops (Auralgan) are available over the counter; they should not be used when tympanic membrane integrity is uncertain. Intranasal corticosteroids are not recommended for treatment of AOM, though they may be considered adjunctively for children with co-existing allergic rhinitis. Zinc supplementation reduces AOM recurrence in Aboriginal and Torres Strait Islander children and in children with deficiency; it is not routinely prescribed in non-at-risk populations.

7. Complications and monitoring

Complications of AOM are divided into intratemporal and intracranial categories. Acute mastoiditis, presenting as post-auricular erythema, oedema, and anterior displacement of the pinna, is the most common intratemporal complication and warrants hospital admission and intravenous antibiotics. Facial nerve palsy, labyrinthitis, and tympanic membrane perforation are additional intratemporal complications. Intracranial complications including meningitis, lateral sinus thrombosis, epidural abscess, and brain abscess are rare but life-threatening and require urgent neuroimaging and neurosurgical referral. Persistent conductive hearing loss from chronic middle ear effusion (OME, also called glue ear) is the most common long-term sequela, with implications for speech and language development, particularly in children under 3 years. All children with suspected persistent effusion beyond 3 months should be referred for audiological assessment. Children with three or more AOM episodes within 6 months or four or more within 12 months warrant referral to an otolaryngologist for consideration of tympanostomy tube (grommet) insertion. Aboriginal and Torres Strait Islander children with any AOM should receive audiological follow-up given the high rates of progression to chronic suppurative otitis media in this population. Vaccination with 20vPCV on the National Immunisation Program schedule reduces the incidence of pneumococcal AOM; ensuring age-appropriate vaccination status should be confirmed and documented at every AOM presentation.

Written for Australian practice and grounded in the guidance named above. Study material only — not medical advice. Always check against current guidelines.