Acute Otitis Media in Childhood

Acute otitis media (AOM) is an infection of the middle ear, defined by the presence of middle ear effusion together with signs of middle ear inflammation — a red, bulging, immobile tympanic membrane.^[1] It is usually preceded by a viral upper respiratory tract infection that impairs eustachian tube function, allowing nasopharyngeal bacteria to invade the middle ear; bacteria are isolated in most cases, but viral co-infection is common. Management is age- and risk-stratified, not one-size-fits-all: children under 6 months and those who are toxic-appearing, highly febrile, or in severe pain need an antibiotic started immediately, while well-appearing children over 6 months with mild, uncomplicated illness and reliable follow-up can be offered watchful waiting for 48 hours first — roughly 60% of AOM resolves spontaneously within that window regardless of antibiotics.^[2]

Typical presentation

An irritable child with 2-3 days of fever, runny nose, and cough — the presentation of a viral URTI — who then develops otalgia. Ear pain is not always easily communicated by infants and toddlers; disturbed sleep, irritability, tugging at the ear, or rubbing the head may be the only clue.

Etiology

Both viral and bacterial pathogens are involved; the primary bacterial pathogens are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Untreated, spontaneous resolution rates differ substantially by pathogen — roughly 20% for S. pneumoniae, 50% for H. influenzae, and 75% for M. catarrhalis — which is part of why a watchful-waiting approach is reasonable for many children. Since pneumococcal conjugate vaccination became routine, the proportion of AOM caused by S. pneumoniae has fallen while H. influenzae has become relatively more common, and penicillin-resistant S. pneumoniae has become substantially less common (well under 1% of invasive isolates in a large Western Canadian surveillance program).

This is why the two escalation questions in AOM are genuinely different: "does this child need more amoxicillin?" (double the dose) versus "does this child need a different drug?" (add clavulanate) — and why understanding which pathogen is more likely changes the choice.

Risk factors for infection

• Recent viral upper respiratory tract infection.
• Exposure to tobacco smoke — a modifiable risk factor for AOM itself.
• Daycare attendance.
• Lack of breastfeeding — breastfeeding is protective against nasopharyngeal colonization and lowers AOM rates.
• Craniofacial anomalies, immunodeficiency, or Down syndrome.

Risk factors for drug-resistant organisms — changes the initial antibiotic choice

• Recent antibiotic use (within the prior 3 months).
• Daycare attendance.
• Recent episode of AOM.
• Prior treatment failure or early recurrence.

A child with any of these should start on high-dose therapy rather than standard-dose, rather than being escalated only after a first agent fails.

Diagnosis requires both of the following

AOM diagnosis needs evidence of both middle ear effusion and middle ear inflammation — neither alone is sufficient.

The four-feature tympanic membrane exam

Proper visual inspection may require the child to be restrained by a parent, good lighting, and removal of any cerumen obscuring the view — do not diagnose AOM from an inadequate exam.

History

• Fever, and nonspecific viral URTI symptoms (cough, coryza) that often precede the ear symptoms.
• Otalgia — often the best clue, but ask about disturbed sleep, irritability, ear tugging, or head rubbing in infants and toddlers who cannot verbalize pain.
• Toxic appearance, temperature ≥39°C, or severe otalgia — these define "severe illness" and change the treatment pathway (see Clinical Decision Algorithm).
• Any episode of AOM in the preceding month, prior mastoiditis, intracranial infection, or facial paralysis — a prior complicated course rules out watchful waiting for this episode.
• Craniofacial anomalies, immunodeficiency, cardiac or pulmonary disease, or Down syndrome — these also rule out watchful waiting.
• Whether parents/caregivers can reliably recognize worsening illness and access medical care if watchful waiting is chosen.

Examination

• Head and neck exam to rule out other referred causes of ear pain — mastoiditis, dental abscess.
• The four-feature tympanic membrane exam above.
• Assess the external auditory canal — significant swelling, erythema, tenderness, or discharge suggests otitis externa instead of, or in addition to, AOM.

• Relieve symptoms — fever, irritability, pain.
• Sterilize the middle ear.
• Prevent complications — mastoiditis, intracranial infection, facial paralysis.
• Avoid inappropriate antibiotic therapy, which drives resistant pathogens and adverse effects such as antibiotic-associated diarrhea.

• Adequate analgesia is essential in the early stages of infection, whether or not an antibiotic is given.
• Watchful waiting, for children who meet the criteria above — provide caregivers with a clear rationale, a safety-net plan for worsening symptoms, and either a delayed/backup antibiotic prescription or a concrete follow-up plan.
• Nasal and oral decongestants, alone or combined with an antihistamine, have not shown benefit in resolving symptoms, infection, or preventing complications — they are not recommended.
• Probiotics can reduce the risk of antibiotic-associated diarrhea when an antibiotic is used (number needed to treat = 9).
• Vaccination — influenza and pneumococcal conjugate vaccines reduce AOM incidence; encourage up-to-date immunization per the current Canadian Immunization Guide, especially in children with recurrent AOM.

Under 6 weeks of age

Refer to the nearest emergency department for full assessment — investigate for bacteremia, since fever in this age group may reflect sepsis rather than isolated AOM.

6 weeks to 6 months

Treat all cases with an antibiotic (no watchful waiting) for 10 days — standard-dose or high-dose amoxicillin as first choice.

Recurrent AOM (≥3 episodes in 6 months or ≥4 in 12 months)

Refer to ENT for consideration of myringotomy and tympanostomy tubes, and for an audiology assessment. Consider conjugate pneumococcal vaccine if under 5 years of age if not already received, and give influenza vaccine yearly at any age.

Penicillin allergy

Verify a true anaphylactic-type allergy — hives; swelling of lips, mouth, or throat; wheezing; hypotension; sudden-onset vomiting and diarrhea — versus a nonspecific reaction such as a rash or GI upset, which parents and patients commonly overestimate as an allergy. Consider penicillin skin testing when the history is unclear. A dissimilar-side-chain cephalosporin (cefuroxime) is an acceptable option even after a prior penicillin allergy, including some IgE-mediated reactions; reserve macrolides/clindamycin for confirmed type I hypersensitivity.

Most children have middle ear effusion for some time after completing therapy — there is no need to treat an abnormal-appearing tympanic membrane in an asymptomatic child. If middle ear effusion persists beyond 3 months, arrange an audiology assessment to evaluate hearing. Treatment failure is defined as no improvement after 72 hours of antibiotic therapy.

1. Verify the AOM diagnosis before assuming treatment failure — reassess for the four-feature tympanic membrane findings and rule out otitis externa or a non-otologic cause of pain.
2. Confirm adherence and correct dosing (weight-based, not a flat pediatric dose).
3. Standard-dose amoxicillin failure: switch to high-dose amoxicillin or high-dose amoxicillin/clavulanate.
4. High-dose amoxicillin failure: switch to high-dose amoxicillin/clavulanate, cefprozil, cefuroxime axetil, or ceftriaxone IM/IV — consider tympanocentesis for culture-directed therapy, especially with recurrent failure.
5. Failure on day 10-28 (recurrence rather than true failure): choose an agent not previously used for this same infection.
6. Persistent or recurrent treatment failure: refer to ENT for tympanocentesis/culture and consider an infectious disease consult, particularly before using levofloxacin, which is reserved for this situation in penicillin-allergic patients after specialist consultation.

• Diagnosing AOM from effusion alone, or inflammation alone — both are required.
• Prescribing decongestants or antihistamines for AOM symptoms — no proven benefit.^[3]
• Treating an asymptomatic child's abnormal-appearing tympanic membrane found incidentally after therapy.
• Labelling a nonspecific reaction (rash, GI upset) as a penicillin "allergy" without clarifying whether it was truly anaphylactic/IgE-mediated — this unnecessarily pushes children toward less effective, broader-spectrum alternatives.
• Using high-dose amoxicillin/clavulanate as a single combined-ratio prescription at high dose — this increases diarrhea risk; give as 2 simultaneous prescriptions instead (see Drug Tables).
• Offering watchful waiting to a child under 6 months, or one who is toxic-appearing, highly febrile, or has a craniofacial anomaly, immunodeficiency, cardiopulmonary disease, or Down syndrome.
• Reaching for azithromycin or clarithromycin as a routine alternative rather than reserving macrolides for true type I beta-lactam hypersensitivity — resistance and failure rates are rising.

How to use this table: Doses are adult doses and require patient-specific confirmation (renal/hepatic function, weight, allergy history). Pediatric dosing is weight-based per the current product monograph unless stated. Drug pricing is intentionally omitted. Select any drug name to open its complete Pharmasist Drug Database page.

Penicillins

Cephalosporins

Lincosamides

Macrolides

Reserve for true type I (anaphylactic-type) beta-lactam hypersensitivity — rising resistance and treatment-failure rates versus amoxicillin.

Fluoroquinolones

Not a routine option — for treatment failure in a penicillin-allergic child, only after infectious disease consultation.