Chronic Suppurative Otitis Media (CSOM)

Background

• CSOM is a chronic middle ear inflammation with tympanic membrane perforation and persistent or intermittent otorrhea (discharge persisting a minimum of 2-6 weeks).
  • The duration of time required to elapse for acute otitis media (AOM) to be considered CSOM is controversial.
    • World Health Organization (WHO) defines CSOM as ≥ 2 weeks of otorrhea.
    • Generally, patients with tympanic membrane perforations and discharge persisting from 6 weeks to 3 months, despite medical treatment, are diagnosed with CSOM.
• Chronic tympanic membrane perforation in CSOM is caused by healing of the outer squamous layer of the tympanic membrane with the inner mucosal layer, resulting in failure to approximate the edges of the perforation and a persistent hole. This may predispose to recurrent middle ear infection and chronic inflammation.
• 65-330 million people worldwide are reported to have CSOM, with the highest rates in developing countries. It is less common in developed countries, with < 1% reported prevalence in the United States, United Kingdom, Denmark, and Finland.
• Risk factors include AOM, especially if refractory to antibiotic therapy, perforation of tympanic membrane (including ventilation tubes), and persistent Eustachian tube dysfunction (as found in children).

Evaluation

• Confirm the diagnosis with otoscopy revealing tympanic membrane perforation plus middle ear inflammation (may be erythematous, polypoid, pale, and/or edematous), typically with persistent otorrhea (≥ 2 weeks).
• Perform audiometric testing to assess for presence and extent of hearing loss in all patients with CSOM.
• Consider computed tomography (CT) of temporal bones in patients with recurrent or persistent CSOM to help identify contributing factors (such as cholesteatoma) and complications (such as mastoid subperiosteal abscess).
• Magnetic resonance imaging (MRI) may be used as an alternative to CT scan for:
  • pediatric patients and patients at risk for long-term complications from CT radiation (for example, patients who have already had a number of CT scans)
  • better assessment of intracranial complications
  • postoperative follow-up after middle ear surgery in cases where CT images are unclear

Management

• Advise patients to maintain a dry ear to help avoid complications.
  • Use ear plugs during bathing and swimming.
  • Dry ears after contact with water.
• Topical otic antibiotics (often used in combination with topical otic dexamethasone, especially in the presence of polyps or granulation tissue) plus aural toilet are first-line conservative management for patients with CSOM.
  • Fluoroquinolones (such as ciprofloxacin) are the most commonly used topical otic antibiotics in the United States due to their established efficacy.
  • A short course of topical otic aminoglycosides can be considered as an alternative to quinolones, but may increase risk for ototoxicity in patients with a perforated tympanic membrane.
  • Perform aural toilet ≥ 2-3 times/week (in combination with topical otic antibiotic drops) to keep ear clean and dry.
• Second-line treatment is systemic antibiotics.
  • Consider oral antibiotics in patients with persistent otorrhea after 3 weeks of aural toilet and topical otic antibiotics, or in patients with severe intracranial complications.
  • Reserve IV antibiotics for patients who are refractory to topical otic and oral antibiotics due to potential to breed antibiotic resistance and risk for systemic side effects.
• Reserve surgery for patients with disease refractory to intensive pharmaceutical therapy.
  • Consider tympanoplasty to improve hearing and reduce risk for recurrent infections in patients with persistent perforations following resolution of infection (usually performed 6-12 months after resolution of infection).
  • Reserve mastoidectomy for patients with:
    • recurrent CSOM
    • cholesteatoma, which may be contributing to recurrent infection
    • severe or life-threatening complications, such as mastoiditis, petrositis, subperiosteal abscess, labyrinthitis, facial nerve paralysis, meningitis, extradural abscess, subdural abscess, or brain abscess