Condition
Chronic Suppurative Otitis Media (CSOM)
Editors: Theodore Schuman MD; Bassem Hanna MBBCh, MSc, MD, PhD, FRCSC; Eddy Lang MDCM, CCFP(EM), CSPQ; Alexander Rae-Grant MD, FRCPC, FAAN
Background Information
Description
- CSOM is a chronic middle ear mucosal inflammation with perforation of the tympanic membrane (ear drum) and persistent or intermittent otorrhea (discharge persisting minimum 2-6 weeks).,
- The duration of time in which acute otitis media (AOM) becomes CSOM is controversial:
- World Health Organization (WHO) defines CSOM as ≥ 2 weeks of otorrhea.
- Generally, patients with tympanic membrane perforations and discharge persisting for ≥ 6 weeks are diagnosed with CSOM.
Also Called
- Chronic otitis media without effusion
- Chronic ear drainage
- Otomastoiditis
- Active chronic otitis media
Definitions
- Otitis media is a progressive continuum of infectious and inflammatory conditions affecting the middle ear.
- Acute otitis media (AOM) is a bacteria- or virus-induced acute inflammation in the middle ear with rapid onset of otalgia and fever.
- Acute suppurative otitis media (ASOM) is a subtype of AOM characterized by pus in the middle ear, with accompanying discharge if the drum perforates. Perforation associated with ASOM typically heals spontaneously.
- Otitis media with effusion (OME) is an inflammation of the middle ear with liquid collected in the middle ear, but no signs or symptoms of an acute infection.
- Chronic suppurative otitis media (CSOM) is chronic middle ear mucosal inflammation with tympanic membrane perforation, with or without persistent otorrhea. Discharge persists for a minimum of 2-6 weeks.
- Reference - Infect Drug Resist 2014 Jan 10;7:15
Types
- CSOM is classified into 2 main types:
- Attico-antral type (attic or marginal perforation) PubMed22311665Current infectious disease reportsCurr Infect Dis Rep20120401142121-7121involves the pars flacida or posterosuperior marginal quadrant.
- Attico-antral type is also called "unsafe" type due to potential for dangerous intracranial complications, most commonly caused by cholesteatoma.
- Discharge is usually scanty and malodorous.
- Patients may have moderate to severe hearing loss, potentially resulting in permanent deafness.
- Tubo-tympanic (mucosal) type (central tympanic perforation) involves the pars tensa.
- Tubo-tympanic type is also called "safe" type as it is less likely to result in serious intracranial complications (such as meningitis and brain abscess) compared with attico-antral type.
- Discharge is mainly mucoid or micropurulent and intermittent.
- It is often associated with respiratory tract infection.
- Patients may have mild hearing loss.
- Reference - Bangladesh Med Res Counc Bull 2002 Apr;28(1):36
- Attico-antral type (attic or marginal perforation) PubMed22311665Current infectious disease reportsCurr Infect Dis Rep20120401142121-7121involves the pars flacida or posterosuperior marginal quadrant.
Image 1 of 7
Normal tympanic membrane (left ear)
This otoscopic view of a healthy tympanic membrane (white arrow) shows a circular, translucent membrane and the protruding handle (blue arrow) of the malleus, the first of the three small bones that connect the membrane to the inner ear. To the right of the handle of the malleus can be seen part of the second bone (black arrow), the incus where it attaches to the stapes. At center left (red arrow) is the reflection of the otoscope light used for illumination, (called a light reflex).
Image 2 of 7
Attic cholesteatoma
Otoscopic view showing a mass of dead skin cells have accumulated in an attic retraction pocket (red arrow). An attic retraction pocket is where the tympanic membrane has retracted in the region surrounding the top of the malleus bone.
Image 3 of 7
Tubotympanic type
Otoscopic view of a perforated tympanic membrane (black arrow) following a bacterial otitis media and failed to heal. There is a purulent discharge (red arrow) in the floor of the middle ear and thickened middle ear mucosa.
Epidemiology
Incidence/Prevalence
- Worldwide, 65-330 million people are reported to have CSOM, with the highest rates in developing countries. 31 million new cases of CSOM are reported annually, with 22.6% of new cases reported in children < 5 years old.,
- The incidence is reported to be similar across sexes, but male individuals are more likely to have accompanying cholesteatoma.
- Both children and adults may be affected.
- Populations most likely to be affected include:
- Inuits of Alaska, Canada, and Greenland
- American Indians
- Australian Aborigines
- CSOM is less common in high-income settings:,
- 0.4% reported prevalence in western Europe.
- 2%-4% reported prevalence in low- and middle-income countries.
- STUDY SUMMARY0.3% prevalence of chronic suppurative otitis media in North AmericaSYSTEMATIC REVIEW: PLoS One 2012;7(4):e36226
- Rates of CSOM are reported to be higher in certain ethnic groups.,
- In the United States, reported prevalence is higher in Indigenous Peoples compared to White or Black populations:
- 8%-30% reported prevalence in Indigenous Peoples.
- 12%-30% reported prevalence in Alaska Native populations.
- 7%-46% reported prevalence in Inuits of Alaska, Canada, and Greenland, American Indians, and Australian Aborigines.
- STUDY SUMMARY15% prevalence of chronic suppurative otitis media in high-risk Australian Aboriginal communitiesCROSS-SECTIONAL STUDY: BMC Pediatr 2005 Jul 20;5:27
- 1%-6% reported prevalence in the South Pacific Islands, Africa, Korea, India, and Saudi Arabia.
- STUDY SUMMARY3.13% prevalence of chronic suppurative otitis media in South Korean patients > 4 years oldCROSS-SECTIONAL STUDY: Laryngoscope 2016 Oct;126(10):2351
- In the United States, reported prevalence is higher in Indigenous Peoples compared to White or Black populations:
- STUDY SUMMARYprevalence of chronic suppurative otitis media in Nigeria appears to be decliningBEFORE AND AFTER STUDY: Eur Arch Otorhinolaryngol 2016 Sep;273(9):2461
Risk Factors
- Risk factors include early or recurrent acute otitis media and persistent tympanic membrane perforation.,
- Acute otitis media (AOM) may precede CSOM, especially if refractory to antibiotic therapy.
- Family history of ear disease may be a risk factor.
- Persistent perforation of tympanic membrane following the use of a ventilation tube may lead to CSOM.
- Early or frequent respiratory infections may increase risk:
- In low-resource settings, exposure to a higher frequency and density of respiratory viruses and bacteria may explain the higher prevalence of CSOM.
- In Indigenous Peoples (such as Aboriginal, Torres Strait Islander, and Inuit Peoples), early and high-density bacterial colonization of the nasopharynx has been found, which may explain the higher prevalence in these groups.
- STUDY SUMMARYsnoring, passive smoke exposure, allergy or atopy, upper respiratory tract infection, and history of acute or recurrent otitis media each associated with increased risk for chronic or recurrent otitis mediaSYSTEMATIC REVIEW: PLoS One 2014 Jan 23;9(1):e86397
- Genetic factors may make some patients more susceptible to otitis media, including:
- Variants of genes involves in the innate immune response, such as:
- Toll-like receptor 4 (TLR4)
- Cluster of differentiation 14 (CD14)
- Mannose-binding lectin-2 (MBL2)
- Surfactant protein A1 (SP-A1)
- Variants of genes involves in the adaptive immune response, such as:
- Interleukin-1 beta (IL-1 beta)
- Interleukin-10 (IL-10)
- Reference - J Genet Genomics 2014 Nov 20;41(11):567
- Variants of genes involves in the innate immune response, such as:
- STUDY SUMMARYEustachian tube dysfunction/immaturity associated with increased risk for chronic suppurative otitis mediaCASE-CONTROL STUDY: Laryngoscope 2015 Sep;125(9):2187
Associated Conditions
- Cholesteatoma is associated with CSOM.
- Otitis media associated with antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is rare.
- It is characterized by:
- Otitis media refractory to antibiotics and tube insertion
- Otitis media with sudden or progressive hearing loss (mixed or sensorineural hearing loss)
- Serum positive for myeloperoxidase or proteinase 3-antineutrophil cytoplasmic antibody (common in conditions such as granulomatosis with polyangiitis or eosinophilic granulomatosis with polyangiitis)
- Improvement with combination therapy of steroids and immunosuppressive agents such as cyclophosphamide or methotrexate
- Vestibular symptoms may or may not be present in patients with otitis media-associated AAV.
- References - Otol Neurotol 2017 Jan;38(1):97, ANCA-associated vasculitis NIH Genetic and Rare Diseases Information Center Apr 2018
- It is characterized by:
- STUDY SUMMARYabnormalities in contralateral ear, including retraction or perforation of tympanic membrane, common in patients with chronic otitis mediaCROSS-SECTIONAL STUDY: Arch Otolaryngol Head Neck Surg 2008 Mar;134(3):290
Etiology and Pathogenesis
Causes
- CSOM is thought to be caused by persistent or recurrent middle-ear infection, leading to inflammation and nonhealing tympanic membrane perforation.,
- Common causes of tympanic membrane perforations differ across age groups.
- In children, perforations are more often caused by acute otitis media or grommet insertion (typically indicated to treat glue ear or acute otitis media).
- In adults, perforations are more often caused by complications from chronic otitis media.
- In developed countries, CSOM often arises from ventilation tube insertion with perforation of the tympanic membrane.
- Infectious agents identified in bacterial biofilms of patients with CSOM include: ,
- Bacteria, most commonly:
- Pseudomonas aeruginosa (18%-67% of cases)
- Staphylococcus aureus (14%-33% of cases)
- Proteus vulgaris (4%-43% of cases)
- Klebsiella pneumoniae (4%-43% of cases)
- Other aerobic bacteria:
- Acinetobacter baumannii
- Enterobacter aerogenes
- Escherichia coli
- Proteus mirabilis
- Streptococcus pneumoniae
- Other anaerobic bacteria:
- Species of Bacteroides
- Species of Clostridium
- Species of Prevotella
- Fusobacterium nucleatum
- Fungi:
- Aspergillus niger
- Aspergillus flavus
- Candida albicans
- Candida krusei
- Bacteria, most commonly:
- STUDY SUMMARYabout 40% of patients with chronic suppurative otitis media reported to have medication-resistant bacteria isolated from ear dischargeCOHORT STUDY: Braz J Otorhinolaryngol 2017 Mar - Apr;83(2):201
Pathogenesis
- The pathogenesis of CSOM is multifactorial and likely involves a combination of immunological factors, genetic predisposition, and anatomical factors.,,
- Chronic inflammation can eventually lead to disintegration of the fibrous layer of the tympanic membrane and disruption of the gaseous pressure in the middle ear, leading to tympanic retraction or perforation.
- Once the tympanic membrane has been perforated, the middle ear becomes more prone to infection.
- Acute otitis media (AOM) may progress to CSOM when:
- Middle ear infection does not respond to antibiotics and persists
- Infection and inflammation spread to the mastoid area
- Perforation of tympanic membrane is persistent, with intermittent or continuous otorrhea
- Atelectasis of tympanic membrane, retraction pocket, or cholesteatoma develop
- Reference - Int J Infect Dis 2014 Dec;29:259
- Bacterial biofilms likely contribute to the pathogenesis of CSOM but their exact role has yet to be determined.
- Biofilms are difficult to eradicate and can contribute to recurrent infection due to:
- Resistance to antibiotics and other antimicrobial compounds
- Ability to attach firmly to damaged tissue (such as exposed osteitic bone and ulcerated middle ear mucosa) or to otological implants (such as tympanostomy tubes)
- Ability to periodically release planktonic bacteria, causing local and systemic illness
- Reference - Otolaryngol Head Neck Surg 2009 Nov;141(5):567
- Evidence for molecular mechanisms contributing to biofilm formation in the middle ear during CSOM is limited.
- Biofilms are difficult to eradicate and can contribute to recurrent infection due to:
- Cytokines have been implicated in the pathogenesis of AOM, but studies in patients with CSOM are lacking:
- High levels of inflammatory cytokines (such as interleukin-8 [IL-8]) have been detected in the middle ear effusion of patients with CSOM.
- Increased messenger RNA (mRNA) and protein levels of tumor necrosis factor alpha (TNF-a), IL-6, IL-1b, and interferon gamma (IFN-y) have also been found in the middle ear mucosa of CSOM patients compared to healthy controls.
- Up-regulation of pro-inflammatory cytokines causes tissue damage and can contribute to the progression from acute to chronic otitis media.
- Complications may develop secondary to:
- Chronic infection and excessive host immune response to inflammation (paracrine and autocrine secretions and regulation of tissue regeneration and associated angiogenesis)
- Acute exacerbation (for example, pathogen overcomes the host's defense) or lowered immunity
- Progressive erosion of bone due to associated cholesteatoma
- Reference - Biomed Res Int 2015;2015:854024
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