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Chronic suppurative otitis media (CSOM) is characterized by at least 2 weeks–3 months of inflammation and infection of the middle ear in patients with a nonintact tympanic membrane (TM). CSOM is one of the most common causes of hearing loss in low-income countries where it typically affects children under 5 years of age. Infections in CSOM are usually polymicrobial. Risk factors include recurrent acute otitis media, frequent upper respiratory tract infections, and poor nutritional status. Patients typically report painless, recurrent discharge from the ear and hearing loss. CSOM is a clinical diagnosis supported by a thorough history and otoscopic findings of otorrhea and a perforated TM. Hearing loss should be evaluated with diagnostic hearing tests. For uncomplicated infections, conservative treatment with topical medications (i.e., antibiotics +/- steroids) is preferred. Neuroimaging, laboratory studies, systemic antimicrobials, and/or surgery may be indicated for patients with persistent CSOM that does not respond to conservative measures. If left untreated, the infection may spread and result in extracranial and intracranial CNS complications. Primary prevention and timely management of acute otitis media are essential to preventing CSOM.
- North America: < 1% prevalence across all ages (adults and children) 
- 4–10% prevalence in some regions
- Most common in children ≤ 5 years of age (peak at ∼ 2 years) 
In many low-income countries, CSOM is the most common cause of hearing loss. 
Epidemiological data refers to the US, unless otherwise specified.
Common pathogens 
CSOM is typically a polymicrobial infection that may include any of the following pathogens:
- Fungal: Aspergillus
Risk factors 
- Painless, recurrent otorrhea for at least ≥ 2 weeks 
- Nonintact tympanic membrane (i.e., a perforation or tympanostomy tube is present) 
- Additional features may include: 
Patients with CSOM are usually clinically well; signs of systemic illness (e.g., fever) should raise concerns for complications. 
Red flags for complications of CSOM 
- Signs of systemic illness, e.g., fever
- Focal neurologic signs
- Altered mental status
Subtypes and variants
Tubotympanic CSOM 
- TM perforation is centrally located and only involves the pars tensa.
- Otorrhea may or may not be foul-smelling. 
- Complications are unlikely.
- No cholesteatoma
Atticoantral CSOM 
TM perforation affecting any of the following locations:
- Peripheral edge of the TM (i.e., marginal perforation)
- Superoposterior quadrant of the TM
- Pars flaccida (i.e., attic perforation)
- Otorrhea is typically foul-smelling. 
- Acquired cholesteatoma
- Increased risk for complications of CSOM
Post-tympanostomy tube CSOM 
- In North America and Europe, this is the most common cause of CSOM. 
- Is one cause of persistent tympanostomy tube otorrhea 
General principles 
- CSOM is a clinical diagnosis; based on characteristic symptoms and otoscopy confirming perforation of the TM.
- An audiogram should be performed to evaluate for hearing loss and to monitor hearing in response to treatment. 
- Further studies are usually only required for persistent symptoms or suspected complications.
Further studies 
- Bacterial, and possibly fungal, cultures of middle ear aspirate 
- Symptoms determine the imaging modality and location.
- For potential findings, see “Diagnostics of mastoiditis” and “ .” 
- Biopsy of persistent granulation tissue to exclude neoplasia or granulomatous disorders. 
- Evaluate for red flags for complications of CSOM and if present:
- For all other patients, determine subtype of CSOM. 
- All patients: Initiate ongoing management of CSOM.
The goals of treatment are to eradicate the infection and ensure healing of the TM (either spontaneously or through surgical repair). 
Conservative management for CSOM 
Preferred: usually determined in consultation with otolaryngology
- Topical antibiotic (usually a fluoroquinolone) with/without a topical steroid, e.g.: ; 
- Aural toilet (unclear benefit) 
- Suspected fungal infection: Add a topical antifungal in consultation with ID. 
Surgical management for CSOM 
- mastoidectomy with or without
- In individuals with complications, additional surgeries may be indicated. 
Ongoing management of CSOM 
- Recommend dry ear precautions until the TM has healed. 
- Advise patients to seek prompt if symptoms develop.
- For patients with recurrent CSOM 
Urgent complications of CSOM 
Similar to urgent, e.g.:
- Local spread (extracranial): facial nerve palsy , ,
- CNS spread (intracranial): lateral sinus thrombosis, ,
Nonurgent complications 
- Persistent hearing loss
We list the most important complications. The selection is not exhaustive.
Prevention of CSOM is predominantlyand the early recognition and .