What are the different types of ear infections?

Types of Ear Infections

Ear infections are classified into several distinct types based on the location and nature of the infection, with the primary categories being otitis media (middle ear infections) and otitis externa (outer ear infections). 1

Otitis Media (Middle Ear Infections)

Otitis media refers to inflammation of the middle ear without reference to etiology or pathogenesis. The main types include:

1. Acute Otitis Media (AOM)

• Definition: Rapid onset of signs and symptoms of inflammation in the middle ear 1
• Diagnostic criteria:
  • Moderate-to-severe bulging of the tympanic membrane
  • Mild bulging with recent (<48 hours) onset of ear pain
  • Intense erythema of the tympanic membrane
  • Acute ear discharge not caused by otitis externa 1
• Severity: Defined as having moderate-to-severe ear pain, ear pain for at least 48 hours, or temperature ≥39°C 1
• Pathogens: Primarily bacterial (Streptococcus pneumoniae, non-typeable Haemophilus influenzae, Moraxella catarrhalis) but always preceded by viral upper respiratory tract infection 1, 2

2. Recurrent Acute Otitis Media

• Definition: Three or more well-documented and separate AOM episodes in the preceding 6 months or four or more episodes in the preceding 12 months with more than one episode in the past 6 months 1
• Management: May require ventilation tubes and adenoidectomy to prevent recurrences 1

3. Otitis Media with Effusion (OME)

• Definition: Fluid in the middle ear without signs or symptoms of acute ear infection 1
• Primary symptom: Conductive hearing loss 1
• Occurrence: Very common, with 80% of children having one or more episodes by age 10 1

4. Chronic Otitis Media with Effusion

• Definition: OME persisting for ≥3 months from the date of onset or diagnosis 1
• Prognosis: Lower rates of spontaneous resolution than new-onset OME 1
• Management: Children with persistent MEE have a poorer prognosis and might benefit from ventilation tubes 1

5. Chronic Suppurative Otitis Media (CSOM)

• Definition: Chronic inflammation of the middle ear and mastoid mucosa with a non-intact tympanic membrane (perforation or ventilation tube) and persistent ear discharge 1
• Complications: A leading cause of hearing loss in developing countries 1
• Pathology: Often involves bacterial biofilms which protect bacteria against antibiotic treatment and the host's immune response 1

Otitis Externa (Outer Ear Infections)

1. Acute Otitis Externa (AOE)

• Definition: Inflammation of the external ear canal, often due to infection 2
• Presentation: Red and inflamed ear canal with discomfort upon manipulation of the affected ear 2
• Treatment: Topical antibiotics with or without corticosteroids 3, 2

2. Fungal Otitis Externa (Otomycosis)

• Prevalence: Common in tropical countries, humid locations, after long-term topical antibiotic therapy, and in immunocompromised patients 1
• Pathogens: Aspergillus species (60%-90%) and Candida species (10%-40%) 1
• Symptoms: Pruritus and thickened otorrhea, which may be black, gray, bluish green, yellow, or white 1
• Diagnosis: Should be suspected if patient fails to respond to initial topical antibiotic therapy 3
• Treatment: Debridement plus topical antifungal therapy; topical antibiotics are contraindicated as they may promote fungal overgrowth 1, 3

3. Necrotizing (Malignant) Otitis Externa

• Population: Predominantly affects elderly, diabetic, or immunocompromised patients 1
• Pathogen: Pseudomonas aeruginosa in >90% of cases 1
• Progression: Untreated disease develops into skull base osteomyelitis that can invade soft tissue, middle ear, inner ear, or brain 1
• Warning sign: Facial nerve paralysis may be an early sign 1
• Diagnosis: Confirmed with raised erythrocyte sedimentation rate plus abnormal CT or MRI scan 1
• Treatment: Surgical debridement and systemic antibiotics covering pseudomonal and staphylococcal infection 1

Special Considerations

Non-intact Tympanic Membrane

• Patients with tympanostomy tubes or perforated tympanic membranes require special consideration 1
• Only non-ototoxic preparations (fluoroquinolones) should be used; avoid aminoglycoside-containing products 3
• Ofloxacin otic solution is FDA-approved for middle ear infections in patients with perforated eardrums or tubes 4

Immunocompromised Patients

• Diabetic or immunocompromised patients are susceptible to otomycosis and necrotizing otitis externa 1
• These patients are more likely to require systemic antibiotics in addition to topical therapy 1
• Ear canal irrigation should be avoided as it may predispose to necrotizing otitis externa 1, 3

Prevention of Recurrent Infections

• Keep ears dry; use ear protection when showering or washing hair 3
• Consider acidifying ear drops after swimming if recurrent episodes occur 3
• Avoid inserting foreign objects into the ear canal 3
• For recurrent folliculitis, gentle cleansing with pH5 neutral bath and shower formulations with tepid water is recommended 3

By understanding the different types of ear infections and their specific management approaches, healthcare providers can effectively diagnose and treat these common conditions while minimizing complications and recurrence.