What are the causes of serious ear discharge?

Five Serious Causes of Ear Discharge

The five serious causes of ear discharge requiring urgent recognition are: chronic suppurative otitis media (CSOM), acute otitis media with tympanic membrane perforation, malignant otitis externa, squamous cell carcinoma of the external auditory canal, and suppurative complications of otitis media including mastoiditis, meningitis, and brain abscess.

1. Chronic Suppurative Otitis Media (CSOM)

• CSOM is defined as persistent ear discharge for ≥2 weeks through a perforated tympanic membrane, representing a leading cause of hearing loss in developing countries 1
• This condition causes life-long sequelae including permanent hearing loss, with an estimated global prevalence of 30 per 10,000 individuals affected by OM-associated hearing loss 1
• The discharge is typically purulent and persistent, requiring non-ototoxic topical antibiotics due to direct middle ear exposure 2
• An estimated 21,000 people die annually from complications of otitis media, predominantly in low-income countries where CSOM is inadequately treated 1

2. Acute Otitis Media with Tympanic Membrane Perforation

• AOM with perforation presents with recent onset of purulent discharge following upper respiratory infection, most commonly in children aged 6-47 months 2
• The discharge represents drainage of infected middle ear fluid through the ruptured eardrum, with common bacterial pathogens including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis 2
• Children with AOM who present with ear discharge have significantly more severe systemic illness, with higher temperature (80% increased odds per degree Celsius), elevated pulse rate (9% increased odds per beat), and higher Yale scores (mean 10.5 versus 9.0) 3
• These children demonstrate proven bacterial infection in 58% of cases and have increased likelihood of adverse outcomes including persistent pain at 1 week, recurrent AOM episodes, and hearing difficulty at 3 months 3

3. Malignant (Necrotizing) Otitis Externa

• Severe otalgia that may be underappreciated by clinicians is a hallmark of acute otitis externa, which can progress to life-threatening necrotizing infection 2
• The condition is characterized by otalgia, tragal tenderness, itching, and discharge, with otoscopic findings of ear canal edema, erythema, and wet debris 2
• Common causative organisms include Pseudomonas aeruginosa and Staphylococcus aureus, which can invade deeper tissues in immunocompromised or diabetic patients 2
• Patients with tympanostomy tubes or pre-existing perforations can develop concurrent middle ear and external canal disease requiring both topical and systemic treatment 2

4. Squamous Cell Carcinoma of the External Auditory Canal

• Malignant tumors can present with non-specific symptoms such as persistent ear discharge, particularly when discharge fails to resolve despite adequate standard therapy 4
• This diagnosis must be considered in adults with non-resolving ear discharge who have been treated repeatedly with antibiotic ear drops without improvement 4
• The key clinical pitfall is failing to adequately visualize the tympanic membrane due to canal debris or discharge, which can lead to missed middle ear or canal pathology 2
• Aural toilet with microsuction, gentle dry mopping, or irrigation should be performed to allow proper examination when discharge persists 2

5. Suppurative Complications of Acute Otitis Media

• Suppurative complications including acute mastoiditis, meningitis, and brain abscesses are rare but potentially life-threatening sequelae of AOM 1
• These complications pose a significant threat in low-income countries where access to appropriate treatment is limited 1
• Local sequelae also include perforation of the tympanic membrane, which can occur as a direct complication of AOM or following ventilation tube placement 1
• If otorrhea persists after a full course of therapy, or if two or more episodes occur within six months, further evaluation is essential to exclude underlying conditions such as cholesteatoma, foreign body, or tumor 5

Critical Diagnostic Approach

• Positive tragal or pinna tenderness suggests otitis externa, while absence of manipulation tenderness indicates middle ear pathology (AOM or CSOM) 2
• Otoscopic findings of bulging, erythematous tympanic membrane with reduced mobility suggest AOM, while visible perforation with purulent discharge indicates AOM with perforation or CSOM 2
• Pneumatic otoscopy showing normal tympanic membrane mobility suggests otitis externa, while reduced or absent mobility indicates middle ear effusion 2
• Cultures should be obtained if infection does not improve after one week of treatment to guide further therapy 5