Ear Infection — Symptoms, Causes & Treatment | MyMedicPlus

Ear infections encompass a spectrum of inflammatory conditions affecting different anatomical zones of the ear. Acute otitis media (AOM) is bacterial or viral infection of the middle ear space, causing fluid accumulation, pressure, and pain behind the tympanic membrane. It is among the most common childhood illnesses worldwide — approximately 80% of children experience at least one episode by age 3, and AOM is the leading reason for antibiotic prescriptions in children in high-income countries. Otitis media with effusion (OME or 'glue ear') is a non-infective accumulation of fluid in the middle ear — the most common cause of acquired conductive hearing loss in childhood, affecting 80% of children at some point. Otitis externa (swimmer's ear) is infection or inflammation of the outer ear canal, typically bacterial (Pseudomonas aeruginosa, Staphylococcus aureus) or fungal (Aspergillus — otomycosis), and is distinct from middle ear disease. Chronic suppurative otitis media (CSOM) is persistent tympanic membrane perforation with recurrent or continuous purulent discharge, causing progressive conductive hearing loss and requiring specialist ENT management.

Bacterial causes of AOM: Streptococcus pneumoniae (most important — causes most severe cases; dramatically reduced by PCV13 vaccination), Haemophilus influenzae non-typeable (most common in the post-PCV era — commonly produces beta-lactamase, causing amoxicillin treatment failures), and Moraxella catarrhalis (commonly self-limiting — nearly all strains produce beta-lactamase). Viral pathogens: RSV, rhinovirus, adenovirus, and influenza virus frequently precede bacterial AOM by causing Eustachian tube inflammation. Pathophysiology: viral URTI causes mucosal oedema and Eustachian tube obstruction, impairing middle ear drainage and creating negative pressure — bacteria ascend from the nasopharynx to colonise stagnant middle ear fluid. Otitis externa causes: Pseudomonas aeruginosa (thrives in warm, moist, macerated canal skin — swimmer's ear), Staphylococcus aureus, and Aspergillus/Candida (otomycosis — more common after antibiotic drop use). Risk factors for AOM: age 6-24 months (immature Eustachian tube — horizontal, short, flaccid); daycare attendance (high viral exposure); bottle feeding supine (milk refluxes through Eustachian tube); passive tobacco smoke (impairs mucociliary clearance); absence of breastfeeding (loss of maternal immunological factors); pacifier use (increases risk 25-30%); cleft palate (direct Eustachian tube dysfunction); incomplete PCV and influenza vaccination; and prior AOM episodes (structural or immune predisposition).

AOM in infants and pre-verbal children: non-specific signs — ear pulling or tugging (unreliable in isolation), persistent inconsolable irritability, difficulty sleeping (pain worsened supine), fever above 38°C (present in 50%), reduced appetite, vomiting, and crying more than usual. Older children and adults: otalgia (severe, unilateral ear pain) is the cardinal symptom; aural fullness or pressure; conductive hearing loss perceived as muffled sound; tinnitus. Spontaneous tympanic membrane perforation: sudden relief of pain (pressure released) followed by purulent otorrhoea — perforation typically heals within 2 weeks. Severe AOM: high fever above 39°C, severe pain, systemic illness (lethargy, poor feeding in infants) — indicates likely bacterial AOM requiring antibiotic therapy. Otitis media with effusion (OME/glue ear): typically asymptomatic or mild conductive hearing loss — child seems inattentive, turns up the television, has delayed speech development; no pain or fever distinguishes OME from AOM. Otitis externa: severe constant otalgia dramatically worsened by manipulation of the pinna or tragus (tragal tenderness — pathognomonic sign); ear canal discharge (watery then purulent); oedema causing conductive hearing loss and blockage; itching often precedes frank infection. Malignant otitis externa (necrotising — in diabetics and immunocompromised): severe pain radiating to the jaw, granulation tissue in the canal, cranial nerve palsies (VII, IX, X — facial nerve most common) — a life-threatening infection requiring urgent imaging and IV antibiotics.

AOM and OME diagnosis requires otoscopic examination of the tympanic membrane (TM). Otoscopic findings: AOM — moderate or severe bulging of the TM (most specific sign — specificity approximately 97%); marked TM erythema; perforated TM with purulent otorrhoea; loss of TM landmarks. OME — TM retracted or neutral; amber, yellow, or grey colour; visible fluid level or air bubbles; reduced TM mobility on pneumatic otoscopy (the most sensitive physical sign for middle ear effusion). Pneumatic otoscopy: positive and negative pressure applied to the ear canal via a sealed pneumatic attachment — assesses TM mobility; absent or reduced mobility is the key finding in effusion; requires adequate canal seal. Tympanometry: measures TM compliance and middle ear pressure — Type B flat tympanogram (low compliance — indicates effusion or perforation); Type C (large negative peak — Eustachian tube dysfunction preceding effusion). Audiometry: pure-tone audiogram with bone conduction — recommended for any child with OME lasting more than 3 months, hearing concerns, or developmental delay; conductive hearing loss of 20-40 dB is typical in OME. Otitis externa: ear canal examination reveals erythema, oedema, and debris — avoid aggressive swabbing in severe oedema; microbiological culture for persistent or treatment-resistant cases; CT scan of the temporal bone if malignant otitis externa or mastoid involvement is suspected (urgently in diabetic patients with severe pain).

AOM management in children: immediate antibiotic treatment is recommended for: infants under 6 months; children 6-24 months with bilateral AOM or severe AOM (TM perforation with discharge, high fever above 39°C, severe otalgia); all children with otorrhoea. Watchful waiting (observation without antibiotics for 48-72 hours) is appropriate for otherwise healthy children over 2 years with non-severe, unilateral AOM — 60-80% resolve spontaneously. Always provide adequate analgesia regardless of antibiotic decision: paracetamol (15 mg/kg every 4-6 hours) and ibuprofen (5-10 mg/kg every 6-8 hours — avoid under 3 months). Antibiotic choices: high-dose amoxicillin (80-90 mg/kg/day in two divided doses for 5-10 days) is first-line — achieves concentrations exceeding MIC of Streptococcus pneumoniae; amoxicillin-clavulanate (90/6.4 mg/kg/day) for treatment failure at 48-72 hours (beta-lactamase producing H. influenzae or M. catarrhalis); azithromycin for confirmed penicillin allergy (10 mg/kg/day for 5 days); ceftriaxone IM for patients unable to take oral antibiotics. Adults with AOM: amoxicillin 500mg three times daily for 5-7 days. Recurrent AOM (3 or more episodes in 6 months, or 4 in 12 months with one in the preceding 6 months): ENT referral for tympanostomy tube (grommets) insertion — reduces AOM recurrence by approximately 1.5 episodes per year and provides ventilation of the middle ear. OME (glue ear): watchful waiting for 3 months (most resolve spontaneously); if persistent beyond 3 months with documented hearing loss above 25-30 dB — grommets insertion plus adenoidectomy in children over 4. Otitis externa: topical antibiotic-steroid drops first-line — acetic acid 2% drops, or ciprofloxacin 0.3%/dexamethasone 0.1% for 7-10 days; ear canal microsuction to remove debris; keep ear dry; systemic antibiotics only for spreading cellulitis; topical clotrimazole for otomycosis.

The vast majority of AOM episodes resolve without sequelae, but a spectrum of local and intracranial complications can occur — particularly when treatment is delayed. Mastoiditis: the most common intratemporal complication — bacterial infection of mastoid air cells presenting with post-auricular erythema, swelling, tenderness, and forward displacement of the pinna; requires IV ceftriaxone and often cortical mastoidectomy; incidence approximately 1-4 per 100,000 children per year. Intracranial complications (rare but life-threatening): bacterial meningitis, epidural or subdural abscess, temporal lobe brain abscess, sigmoid sinus thrombosis (fever, headache, papilloedema), subdural empyema. Facial nerve palsy: from pressure on the fallopian canal — rare, requires urgent IV antibiotics and ENT review. Chronic suppurative otitis media (CSOM): persistent TM perforation with recurrent or chronic purulent otorrhoea, causing ossicular chain damage and conductive hearing loss — requires ENT management and often myringoplasty (repair of TM perforation). Cholesteatoma: pathological accumulation of squamous epithelium in the middle ear and mastoid — locally invasive, progressively eroding ossicles, semicircular canals, facial nerve canal, and tegmen; presents with painless foul-smelling otorrhoea and progressive hearing loss; requires surgical excision (mastoidectomy). Hearing impairment and developmental effects: OME causes conductive hearing loss of 20-40 dB during critical language development — even mild hearing loss impairs phonological awareness, vocabulary development, and literacy if untreated over months.

Breastfeed exclusively for at least 6 months — maternal IgA and immune factors reduce nasopharyngeal colonisation with AOM pathogens; breastfed infants have 30-50% lower AOM risk compared to formula-fed infants. Vaccination: complete the scheduled pneumococcal conjugate vaccine (PCV13/PCV15) course — dramatically reduces Streptococcus pneumoniae-related AOM; annual influenza vaccination reduces influenza-related secondary AOM by approximately 30%. Avoid passive tobacco smoke exposure — parental smoking doubles the child's risk of recurrent AOM and OME through mucociliary dysfunction. Feed infants in an upright position — prevents milk from pooling and refluxing through the Eustachian tube. Limit pacifier (dummy) use — associated with a 25-30% increased AOM risk through Eustachian tube dysfunction. Practice regular handwashing to reduce transmission of the viral URTIs that precipitate AOM. Reduce daycare group size exposure where possible during the first 2 years of life. Otitis externa prevention: use well-fitted silicone earplugs during swimming; dry the ear canal thoroughly after water exposure (tilt head to drain; hair dryer on low heat, 30 cm distance); never insert cotton buds into the ear canal (disrupts protective cerumen and traumatises canal skin); instil 2% acetic acid (white vinegar diluted 1:1) or swimmer's ear drops after prolonged water exposure in susceptible individuals.

Take your child to emergency services immediately for: fever above 39°C with marked irritability and a stiff neck or rash (possible meningitis — emergency); swelling behind the ear with ear displacement (mastoiditis requiring emergency ENT assessment and IV antibiotics); facial weakness or asymmetry (facial nerve palsy — rare complication requiring urgent ENT review); or sudden profound hearing loss. See your GP or paediatrician within 24–48 hours for: a child under 6 months with any ear infection symptoms; any child with high fever above 39°C and ear pain; ear pain lasting more than 24 hours without improvement; ear discharge (perforated eardrum); or failure to respond to 48–72 hours of watchful waiting. Refer to ENT if: a child has three or more episodes of AOM in 6 months; persistent otitis media with effusion lasting more than 3 months with hearing loss; or any adult with unilateral middle ear effusion persisting beyond 6 weeks (exclude nasopharyngeal carcinoma).