Ear Infection — Acute Otitis Media & External Otitis Causes & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Ear infections encompass several distinct clinical entities depending on the anatomical location affected. Acute otitis media (AOM) — infection of the middle ear (tympanic cavity) — is the most common, affecting 75% of children at least once by age 3 and the leading cause of antibiotic prescription in children globally. Otitis media with effusion (OME, 'glue ear') — chronic fluid accumulation in the middle ear without acute infection — is the most common cause of childhood hearing loss. Otitis externa ('swimmer's ear') — infection of the external auditory canal — is predominantly a bacterial or fungal condition in adults. Chronic suppurative otitis media (CSOM) — persistent tympanic membrane perforation with discharge — requires specialist management. Understanding the type of ear infection is essential for appropriate treatment.

Acute otitis media: bacterial (Streptococcus pneumoniae, non-typeable Haemophilus influenzae, Moraxella catarrhalis) and viral (RSV, rhinovirus, influenza — often precede bacterial superinfection via Eustachian tube dysfunction) causes. Risk factors: age under 2 years (Eustachian tube is shorter, more horizontal), daycare attendance (increased viral exposure), bottle-feeding (versus breastfeeding, which reduces AOM risk by 30–50%), passive smoking, dummy (pacifier) use, prone sleeping, and overcrowding. Otitis externa: Pseudomonas aeruginosa and Staphylococcus aureus predominate; fuelled by moisture (swimming, showering), trauma to the ear canal lining (cotton bud use), hearing aid use, eczema, and narrow external canals. Fungal otitis externa (otomycosis — Aspergillus, Candida) occurs in humid climates and after topical antibiotic use.

Acute otitis media: sudden-onset severe ear pain (otalgia), fever (above 38°C), irritability and reduced feeding in infants, hearing loss in the affected ear, and tugging or pulling at the ear (especially in pre-verbal children). Otoscopy shows erythematous, bulging tympanic membrane with loss of light reflex and landmarks. Tympanic membrane perforation (with mucopurulent discharge) provides pain relief — the membrane may heal spontaneously. Otitis media with effusion: painless, bilateral hearing loss in a child (may present as inattention, behavioural problems, or speech delay); otoscopy shows retracted, dull TM with an air-fluid level or amber discolouration. Otitis externa: severe, diffuse ear canal pain (worse on tragal pressure or movement of the pinna), pruritus, otorrhoea (discharge), and ear canal oedema causing conductive hearing loss. Fever is uncommon in uncomplicated otitis externa.

Acute otitis media diagnosis is clinical — based on acute-onset symptoms plus otoscopic evidence of middle ear inflammation (erythematous, bulging, or perforated TM). Pneumatic otoscopy assesses TM mobility — reduced mobility confirms middle ear effusion. Tympanometry: Type B flat trace (no peak) confirms middle ear effusion; Type A is normal; Type C indicates Eustachian tube dysfunction. Otitis media with effusion: tympanometry plus pure tone audiogram showing conductive hearing loss (bone-air gap above 20 dB). Otitis externa: clinical diagnosis based on examination — ear canal oedema, erythema, and discharge; discharge culture if treatment fails. If AOM is recurrent (3 episodes in 6 months or 4 in a year), audiological assessment and ENT referral are indicated. Mastoiditis (serious complication of AOM): retroauricular tenderness, pinna pushed forward, fever, and toxicity — requires CT temporal bones and urgent ENT review.

Acute otitis media: analgesia first (paracetamol or ibuprofen — reduces pain and fever effectively). Immediate antibiotics if: under 2 years with bilateral AOM, TM perforation with discharge, systemic toxicity, immunocompromise, or symptoms not improving after 72 hours. First-line: amoxicillin 40–90 mg/kg/day (children) or 500 mg TDS (adults) for 5–7 days. Penicillin-allergic: clarithromycin or erythromycin. Co-amoxiclav for treatment failure or recurrent AOM. Delayed prescribing strategy (written prescription to fill only if no improvement in 72 hours) reduces antibiotic use by 75% with equivalent outcomes. Otitis media with effusion: watchful waiting for 3 months (most resolve spontaneously); autoinflation (Otovent) may help; persistent OME with hearing loss above 25 dB for over 3 months: ENT referral for grommet insertion (ventilation tube) — restores hearing within 2–4 weeks; adenoidectomy often performed concurrently. Otitis externa: thorough aural toilet (microsuction), topical antibiotic/steroid drops (ciprofloxacin + dexamethasone; acetic acid 2% — mildly antifungal and antibacterial); keep ear dry; ear canal wick for severe canal swelling; oral antibiotics (flucloxacillin) only for spreading cellulitis; analgesia.

Most acute otitis media resolves without complications, but untreated or recurrent cases can cause significant harm. Persistent otitis media with effusion (OME/'glue ear') is the most common complication, affecting 40% of children after AOM — chronic fluid in the middle ear causes conductive hearing loss of 20-30 dB, affecting speech, language, and educational development. Tympanic membrane perforation from pressure buildup causes hearing loss and increases susceptibility to further infections; most perforations heal spontaneously, but chronic perforations require surgical repair (myringoplasty). Chronic suppurative otitis media (CSOM) — persistent ear discharge through a perforated eardrum — causes conductive hearing loss and may lead to cholesteatoma. Cholesteatoma (keratinised squamous epithelium in the middle ear) is a serious, destructive complication — eroding the ossicular chain, causing mixed hearing loss, and potentially extending into the mastoid. Mastoiditis (spread of infection to the mastoid air cells) presents with post-auricular swelling, redness, and pinna pushed forward — requires IV antibiotics and may necessitate mastoidectomy. Intracranial complications (meningitis, brain abscess, lateral sinus thrombosis) are rare but potentially fatal. Facial nerve palsy can result from infection extending along the facial nerve canal through the middle ear.

Reduce AOM risk in children: exclusive breastfeeding for 6 months reduces AOM incidence by 30%; pneumococcal conjugate vaccine (PCV13/PCV15) reduces vaccine-type pneumococcal AOM; annual influenza vaccination for high-risk children; avoid passive smoking completely; discontinue dummy use after 6 months; keep children home from daycare during acute respiratory infections; treat allergic rhinitis to improve Eustachian tube function. For recurrent AOM (3+ episodes per 6 months): ENT referral for consideration of grommet insertion (ventilation tubes) or prophylactic antibiotics. Prevent otitis externa: avoid inserting anything in the ear canal (no cotton buds — 'nothing smaller than your elbow'); after swimming, tilt head to each side to drain water, or use a hair dryer on low setting; topical acetic acid 2% drops after swimming in susceptible individuals.

Take your child to the GP the same day if: they are under 2 with severe ear pain, high fever, or are very unwell; an infant under 6 months has any ear infection symptoms; or pain has not improved after 24–48 hours. Seek emergency assessment immediately for: retroauricular redness, swelling, or tenderness (mastoiditis), facial weakness (indicating facial nerve involvement), severe headache, neck stiffness, or altered consciousness (intracranial spread). For adults: attend the GP for persistent ear pain longer than 72 hours, significant hearing loss, or visible perforation with discharge. Persistent conductive hearing loss in a child (with or without recurrent ear infections) warrants GP referral for tympanometry and audiological assessment to determine if grommets are needed.