This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Go to /pro/cpd-dashboard page

This page is worth 0.05 CPD credits. CPD dashboard

Go to /account/subscription-details page

This page is worth 0.05 CPD credits. Upgrade to Pro

Chronic suppurative otitis media (CSOM)

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

Chronic suppurative otitis media (CSOM), (also often referred to as chronic otitis media (COM))

  • is a chronic inflammation and infection of the middle ear and mastoid cavity, characterised by ear discharge (otorrhoea) through a perforated tympanic membrane

  • no universally accepted definition of CSOM. Some define CSOM in patients with a duration of otorrhoea of more than two weeks but others may consider this an insufficient duration, preferring a minimum duration of six weeks or more than three months (1)
    • some include diseases of the tympanic membrane within the definition of CSOM, such as tympanic perforation without a history of recent ear discharge, or the disease cholesteatoma (a growth of the squamous epithelium of the tympanic membrane)
      • if considering two types of chronic suppurative otitis media then may be considered as:
        • safe, tubotympanic or mucosal disease:
          • there is a perforation of the pars tensa, and local destruction doesn't occur
        • unsafe, atticoantral or bony disease:
          • there may be a cholesteatoma developing in the pars flaccida and posterosuperior portion of the pars tensa. This may lead to local destruction of bone

Clinical features of CSOM include:

  • predominant symptoms of CSOM are ear discharge and hearing loss
    • ear discharge can be persistent or intermittent - dscharge is often visible and odorous (3) and hence leads to social embarassment
    • most patients with CSOM experience temporary or permanent hearing loss with average hearing levels typically between 10 and 40 decibels
      • hearing loss can have an impact on speech and language skills, employment prospects, and on children's psychosocial and cognitive development, including academic performance (2)
      • there may be tinnitus and/or a sensation of pressure in the ear (7)
      • CSOM can also progress to serious complications in rare cases (and more often when cholesteatoma is present):
        • extracranial complications (such as mastoid abscess, postauricular fistula and facial palsy) or
        • intracranial complications (such as otitic meningitis, lateral sinus thrombosis and cerebellar abscess) (4)


If suspected chronic suppurative otitis media (CSOM) (7):

  • if diagnosis of CSOM is suspected then do not swab the ear or initiate treatment - role of ear swabs in CSOM is controversial
    • some expert opinion suggest that that treatment failure is rarely due to resistant organisms (topical antibiotic concentrations are so high that they kill even resistant organisms) and is mainly due to poor administration
  • referral for ENT assessment is indicated
  • suggested that ENT referral is required because need to:
    • allow confirmation of diagnosis of CSOM.
      • microsuctioning or debridement will allow examination of tympanic membrane perforation
        • will facilitate detection of other pathology such as ossicular lesions, polyps, cholesteatoma, mucosal oedema or granulation tissue
      • CT imaging of the temporal bone may be required - will allow the identification of the presence of cholesteatoma or granulation; as well as assessment of tympanic membrane and surrounding structures
    • allow assessment of risk of complications - if a perforation is in the atticoantral tympanic membrane then higher risk of complications such as cholesteatoma
    • treatment initiation:
      • topical quinolones are used off-licence in CSOM
      • aminoglycosides are a potential alternative may cause ototoxicity
      • specialist supervision is therefore indicated for both of these treatment option
      • surgical intervention may be required to repair the tympanic membrane

A systematic review states (5):

  • treatments for CSOM may include topical antibiotics (administered into the ear) with or without steroids, systemic antibiotics, topical antiseptics and ear cleaning (aural toileting), all of which can be used on their own or in various combinations
  • surgical interventions to repair the tympanic membrane are an option in cases where complications arise or in patients who have not responded to other treatments
  • cholesteatoma is considered by many clinicians to be a variant of CSOM, but it will not respond to non-surgical treatment (or will only respond temporarily)

A further systematic review (6) has investigated the use of systematic antibiotics in CSOM:

  • limited amount of evidence available to examine whether systemic antibiotics are effective in achieving resolution of ear discharge for people with CSOM
  • when used alone (with or without aural toileting)
    • very uncertain if systemic antibiotics are more effective than placebo or no treatment
    • when added to an effective intervention such as topical antibiotics, there seems to be little or no difference in resolution of ear discharge (low-certainty evidence)
    • very uncertain whether one class of systemic antibiotic may be more effective than another


  • WHO definition of chronic suppurative otitis media used a duration of otorrhoea of two weeks
  • if earache or headache is present, the clinician should consider the possibility of a complication - when considering CSOM in the developing world (2)
    • common extracranial complications were subperiosteal abscess andlabyrinthine fistula; facial weakness, post-auricular swelling and otalgia were the most frequent symptoms and signs
    • meningitis was the most common intracranial complication, usually presenting with fever, headache, and meningeal signs
  • CKS suggests to suspect CSOM if (7):
    • ear discharge persisting for more than 2 weeks, without ear pain or fever.
    • hearing loss in the affected ear
    • there also may be an a history of allergy, atopy, and/or upper respiratory tract infection.
    • there may be tinnitus and/or a sensation of pressure in the ear
    • clinical features (red flags) suggested when to consider either intracranial complications or mastoiditis include :
      • headache
      • vertigo
      • fever
      • nystagmus
      • facial paralysis
      • post auricular tenderness/swelling


Related pages

Create an account to add page annotations

Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.