Is Ear Discharge Always Otitis Externa?
No—ear discharge is not always otitis externa; it can originate from the middle ear (acute otitis media with perforation, chronic suppurative otitis media, or tympanostomy tube otorrhea) or from the external canal (otitis externa), and distinguishing between these requires targeted history and otoscopic examination.
Critical Diagnostic Framework
The key to diagnosis is determining whether the discharge originates from the external auditory canal or the middle ear space 1, 2.
Step 1: Assess Tragal/Pinna Tenderness
- Positive tragal or pinna tenderness strongly indicates otitis externa (infection confined to the external canal) 1, 2, 3, 4.
- Absent tragal tenderness suggests middle ear pathology—acute otitis media with perforation or chronic suppurative otitis media 2.
Step 2: Perform Aural Toilet and Otoscopic Examination
Remove all debris, cerumen, and discharge using gentle suction, dry mopping, or irrigation (body-temperature water/saline) to visualize the tympanic membrane 1, 2.
- In diabetic or immunocompromised patients, use only atraumatic suction under microscopy—avoid irrigation to prevent necrotizing otitis externa 1.
Visualize the tympanic membrane:
- Intact tympanic membrane with canal edema/erythema = otitis externa 1, 3, 4.
- Visible perforation with purulent discharge = acute otitis media with perforation or chronic suppurative otitis media 5, 2.
- Tympanostomy tubes present with discharge = tube otorrhea (middle ear infection draining through the tube) 5, 2.
Step 3: Assess Clinical Context
- Recent water exposure or swimming strongly suggests otitis externa 2, 3, 4, 6.
- Recent upper respiratory infection in a child aged 6–47 months suggests acute otitis media with perforation 2.
- Persistent discharge ≥2 weeks to 3 months through a non-intact tympanic membrane = chronic suppurative otitis media 2.
Treatment Implications Based on Diagnosis
Otitis Externa (External Canal Infection)
First-line: Topical antimicrobial drops (fluoroquinolones, aminoglycosides/polymyxin B, or acetic acid 2%) 1, 3, 4.
Oral antibiotics are NOT indicated for uncomplicated otitis externa 1, 3, 4.
- Reserve systemic antibiotics for: extension beyond the canal, diabetes/immunocompromise, severe edema preventing topical delivery, or failure after 48–72 hours 1.
Acute Otitis Media with Perforation
- Use non-ototoxic topical quinolones (ofloxacin or ciprofloxacin) 2.
- Consider systemic antibiotics (amoxicillin-clavulanate or cephalosporins) targeting Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis based on severity, age, and bilateral disease 2.
Chronic Suppurative Otitis Media
Tympanostomy Tube Otorrhea
- Topical quinolone drops (with or without corticosteroid) achieve 77–96% cure rates versus 30–67% with oral antibiotics 2.
- Limit topical therapy to ≤10 days to prevent otomycosis 2.
- Avoid systemic antibiotics due to inferior outcomes 2.
Common Pitfalls to Avoid
- Assuming all ear discharge is otitis externa without visualizing the tympanic membrane leads to missed middle ear pathology 2.
- Failing to perform aural toilet before examination prevents adequate visualization and diagnosis 1, 2.
- Using aminoglycoside drops when tympanic membrane integrity is uncertain risks ototoxicity 1, 2.
- Prescribing oral antibiotics for uncomplicated otitis externa occurs in 20–40% of cases inappropriately 1.
- Irrigating the ear in diabetic or immunocompromised patients can precipitate necrotizing otitis externa 1.
Special Populations
- Diabetic or immunocompromised patients: Monitor closely for necrotizing otitis externa; avoid irrigation; consider systemic antibiotics even for seemingly uncomplicated cases 1, 2.
- Children with tympanostomy tubes: Discharge represents middle ear infection draining through the tube, not external canal infection 5, 2.
- Patients with Down syndrome or cleft palate: Higher risk of middle ear effusion and require closer monitoring 5.