Ear infections

Introduction

Ear infections are a group of conditions involving inflammation and infection of the ear structures, which can be external (otitis externa), middle (otitis media), or inner ear (labyrinthitis/otitis interna). They are among the most common reasons for healthcare visits, especially in children, but also occur in adults.

The site of infection determines the clinical presentation, causative organisms, and treatment approach. The major types are:

• Otitis externa (OE) – infection of the external auditory canal.

• Otitis media (OM) – infection of the middle ear space, often with effusion.

  • Acute otitis media (AOM)

  • Otitis media with effusion (OME)

  • Chronic suppurative otitis media (CSOM)

• Otitis interna (labyrinthitis) – infection/inflammation of the inner ear structures.

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Epidemiology

• AOM: Peak incidence in children aged 6–18 months; very common by age 3.

• OE: Occurs in all ages, often in swimmers (“swimmer’s ear”).

• Labyrinthitis: Less common; typically follows viral URTI or AOM.

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Etiology and Pathogens

Otitis Externa

• Bacterial (most common):

  • Pseudomonas aeruginosa

  • Staphylococcus aureus

• Fungal (otomycosis):

  • Aspergillus niger, Candida albicans

• Predisposing factors: water exposure, trauma from cotton buds, eczema, hearing aids.

Acute Otitis Media

• Bacterial:

  • Streptococcus pneumoniae

  • Haemophilus influenzae (non-typeable)

  • Moraxella catarrhalis

• Viral: RSV, rhinovirus, influenza, adenovirus (often preceding bacterial superinfection).

• Risk factors: young age, daycare attendance, passive smoking, cleft palate, Down syndrome.

Chronic Suppurative Otitis Media

• Persistent middle ear infection with tympanic membrane perforation and discharge.

• Common organisms: P. aeruginosa, S. aureus, Proteus spp., anaerobes.

Labyrinthitis

• Viral (herpes simplex, mumps, measles, influenza)

• Bacterial spread from AOM, meningitis, or mastoiditis.

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Pathophysiology

Otitis Externa

Breakdown of skin-cerumen barrier → moisture/trauma → bacterial/fungal overgrowth → inflammation and edema of ear canal.

Otitis Media

Eustachian tube dysfunction from URTI or allergies → negative middle ear pressure → fluid accumulation → bacterial proliferation.

Labyrinthitis

Direct infection or post-viral inflammation damages vestibular and cochlear structures.

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Clinical Features

Otitis Externa

• Ear pain (otalgia), worse with tragal pressure or auricle movement

• Ear canal swelling, erythema

• Purulent discharge

• Itching (especially fungal)

• Hearing loss (conductive, due to debris/swelling)

Acute Otitis Media

• Rapid onset ear pain, fever, irritability (children)

• Hearing loss, blocked ear sensation

• Otoscopic findings: bulging, erythematous tympanic membrane, reduced mobility

• Possible otorrhea if TM perforates

Otitis Media with Effusion

• Conductive hearing loss without acute pain or fever

• TM may appear dull, retracted, with fluid level or bubbles

Chronic Suppurative Otitis Media

• Persistent/recurrent ear discharge through perforated TM

• Conductive hearing loss

Labyrinthitis

• Sudden-onset vertigo

• Hearing loss (sensorineural)

• Tinnitus

• Nausea, vomiting, gait imbalance

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Diagnosis

History and Examination

• Pain characteristics, hearing changes, discharge

• Preceding URTI, water exposure, trauma

• Otoscopic examination (pneumatic otoscopy for AOM/OME)

Investigations (if needed)

• Tympanometry for middle ear effusion

• Audiometry for hearing assessment

• Ear swab for culture (CSOM or persistent OE)

• Imaging (CT/MRI) for suspected complications

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Management

General Principles

• Treat according to infection site and severity

• Relieve symptoms (pain, fever)

• Prevent complications and recurrence

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Otitis Externa

Mild to moderate bacterial OE:

• Topical antibiotic + steroid drops (e.g., ciprofloxacin + hydrocortisone, neomycin/polymyxin B + hydrocortisone)

• Analgesics (paracetamol, NSAIDs)

• Ear canal cleaning by healthcare professional

Fungal OE:

• Topical antifungals (e.g., clotrimazole 1% drops)

• Keep ear dry

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Acute Otitis Media

• Pain management: paracetamol or ibuprofen

• Antibiotics (when indicated):

  • First-line: Amoxicillin 500 mg every 8 hours for 5–7 days (children: 40–90 mg/kg/day in divided doses)

  • Alternative (penicillin allergy): macrolide (azithromycin, clarithromycin)

• Watchful waiting in mild cases for 48–72 hours in older children/adults without severe symptoms

• Myringotomy for severe pain or complications

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Otitis Media with Effusion

• Usually resolves spontaneously within 3 months

• No antibiotics unless secondary infection develops

• Hearing assessment; consider tympanostomy tubes if persistent with hearing loss

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Chronic Suppurative Otitis Media

• Aural toilet (microsuction)

• Topical antibiotics (e.g., ciprofloxacin drops)

• Surgical repair (tympanoplasty) for persistent perforation

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Labyrinthitis

• Supportive: bed rest, vestibular suppressants (short-term: meclizine, diazepam)

• If bacterial: IV antibiotics (e.g., ceftriaxone) and treat primary source (e.g., mastoidectomy)

• Corticosteroids in some viral/post-viral cases to reduce inflammation

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Complications

Otitis Externa

• Malignant otitis externa (necrotizing OE; Pseudomonas infection in diabetics/immunocompromised)

Otitis Media

• Mastoiditis

• Hearing loss (conductive or sensorineural)

• Tympanic membrane perforation

• Cholesteatoma

• Intracranial spread (meningitis, brain abscess, lateral sinus thrombosis)

Labyrinthitis

• Permanent hearing loss

• Chronic balance dysfunction

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Prevention

• Avoid cotton buds and ear trauma

• Keep ears dry after swimming/bathing (drying drops if recurrent OE)

• Vaccination: pneumococcal, influenza (reduce AOM risk)

• Manage allergic rhinitis to reduce eustachian tube dysfunction

• Prompt treatment of URTIs and sinus infections

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Prognosis

• Most acute ear infections resolve without long-term effects if treated appropriately

• Chronic or complicated infections require specialist ENT management to prevent irreversible damage