This article aims to provide an overview Acute Otitis Media – including associated clinical signs, investigations, management and possible complications. This condition is one of the most frequent diagnoses for children seeking acute medical care and, as such, it is imperative that we have a good understanding of it!

 


Anatomy of the Middle Ear

The middle ear is one of three major components of the ear. The middle ear is located within the petrous temporal bone, between the tympanic membrane and the lateral aspect of the inner ear (see diagram). Its chief function is to transmit vibrations from the external ear to the inner ear where they are interpreted as sounds.

The middle ear contains the three smallest bones in the body – the ossicles. The largest of these is the malleus (colloquially – ‘the hammer’) which is attached to the tympanic membrane by its handle. The malleus articulates with the incus (‘the anvil’), which in turn attaches to the stapes. The stapes (‘the stirrup’) is the smallest of the ossicles and joins the inner ear at the oval window.

The middle ear contains two small muscles; the tensor tympani and the stapedius. These muscles are responsible for the acoustic reflex and will contract in response to sudden loud noises to prevent movement of the ossicles damaging the inner ear.

The Middle Ear and Ossicles

Figure 1: The Middle Ear and Ossicles ¹

 

 

The Eustachian tube (or auditory tube) travels between the middle ear and opens at the fossa of Rosenmuller in the lateral wall of the nasopharynx. This tube is 1/3 bone and 2/3 cartilage and is lined by ciliated pseudostratified columnar epithelium. The Eustachian tube helps to equalise pressure in the middle ear. It is shorter and straighter in children leading to an increased risk of acute otitis media and otitis media with effusion.

The mastoid process, located in the inferior aspect of the temporal bone, contains a cavity called the mastoid antrum. The antrum is filled with a collection of air cells that help maintain the pressure of the middle ear.

 


Types of Otitis Media

Acute Otitis media (AOM) is inflammation of the middle ear of less than 3 weeks duration, and is usually secondary to a bacterial infection spreading from the upper respiratory tract via the Eustachian tube.

Acute suppurative otitis media (ASOM) is a complication of AOM where there is a perforation of the tympanic membrane with mucopurulent discharge.

 

Otitis media with effusion (OME, also called serous otitis media) is defined as middle ear fluid without acute signs of infection. It occurs when fluid collects within the middle ear causing pain and hearing loss. It is thought to be secondary to:

  • Recurrent inflammation of the middle ear causing the epithelium to increase production of mucous
  • Eustachian tube dysfunction preventing adequate clearance of mucous

 


Risk factors

Risk factors for AOM:

  • Young age, with peak incidence in first year of life
  • Male gender
  • Daycare or Nursery attendance
  • Lack of breastfeeding (bottle feeding)
  • Exposure to tobacco smoke and air pollution
  • Congenital craniofacial abnormalities including Trisomy 21 and cleft palate
  • Immunocompromised children

 

Risk factors for OME:

  • As per AOM: young age, male gender, bottle feeding and daycare attendance, exposure to tobacco smoke and craniofacial abnormalities (particularly cleft palatte)
  • Atopy/asthma
  • Chronic respiratory conditions including Kartagener syndrome and cystic fibrosis

Clinical History

Symptoms to ask about include:

  • Recent onset ear pain (Otalgia) – irritability or ear pulling noted in preverbal children
  • Fever, anorexia/poor feeding, vomiting/diarrhoea or lethargy – may indicate AOM
  • Aural fullness

 

Findings associated with complications of AOM:

  • Veritgo
  • Nystagmus
  • Tinnitus
  • Swelling around the ear
  • Facial paralysis – possibly suggesting invasion into the temporal bone in AOM
  • Otorrhoea – may suggest ASOM or a concurrent otitis externa
  • Hearing loss
  • Headache or photophobia and neck stiffness may suggest meningitis as a complication of AOM
  • Speech and language delay in recurrent OME in young children
  • Poor school performance and bad behaviour in recurrent OME/ AOM

 


Examination

For a comprehensive guide to otoscopy and hearing assessment, check out our guide here.

Inspection

  • Inspection of the pinna for erythema/ heat and mucopurulent discharge.
  • Presence of a tender boggy swelling behind the pinna with loss of the post-auricular sulcus and auricular proptosis suggests acute mastoiditis – an ENT emergency.

 

Otoscopy

  • AOM findings:
    • Red, bulging and tender tympanic membrane
    • Mucopurulent discharge in acute suppurative otitis media

 

  • OME findings:
    • Dull yellow/grey tympanic membrane
    • Bulging with loss of cone of light reflex
    • Visible fluid level behind the tympanic membrane

Hearing assessment

  • Rinne and Weber’s tests demonstrate conductive hearing loss

 

  • Free field voice testing (at an arm’s length):
    • Correctly identifies 50% or more words when whispered: normal hearing
    • Correctly identifies 50% or more words when at a conversational level: mild-moderate hearing loss
    • Correctly identifies 50% or more words when said in a loud voice: severe hearing loss

 

 

Other examinations to consider

 


Investigations

AOM and OME are clinically diagnosed, however investigations to consider include:

  • Ear swab for microbiology, culture and sensitivity (MC&S)
  • Audiological assessment for determination of ongoing hearing loss: Pure tone Audiography and Tympanometry (may also be used to determine the presence of middle ear fluid in AOM and OME)

 


Management

Acute Otitis Media

AOM is a self-limiting disease lasting 3 days to 1 week and often does not require antibiotics. Antibiotics have been shown to make little difference to the number of children whose symptoms improve as well as making little difference to the number of children with recurrent infections, short-term hearing loss or perforated tympanic membranes.

 

NICE Guidelines recommend

  • Reassurance
  • Simple analgesia and antipyrexial agents (i.e. paracetamol or ibuprofen).

 

  • Immediate antibiotics and consideration of referral for admission to hospital if the child or young person:
    • is systemically unwell
    • has signs/symptoms of a more serious condition
    • has a high risk of complications (i.e. mastoiditis)

 

  • In the presence of otorrhoea or the child is under 2 y.o. with bilateral AOM:
    • Consider providing a back-up prescription (for use if no improvement in 3 days) or immediate antibiotic prescription (with advice to seek medical help if symptoms worsen).

 

  • Choice of antibiotic agent:
    • First line: Amoxicillin
      • 1 to 11 months: 125 mg three times a day for 5 to 7 days
      • 1 to 4 years: 250 mg three times a day for 5 to 7 days
      • 5 to 17 years: 500 mg three times a day for 5 to 7 days
    • Alternative first line if penicillin allergy: Clarithromycin or Erythromycin.
    • Second line: Co-amoxiclav (worsening symptoms or first choice taken for at least 2 to 3 days). Consult local microbiologist if penicillin allergic.

 

  • Decongestants or antihistamines have not been shown to alleviate symptoms.

Otitis Media with Effusion

OME is a self-limiting disease with 50% resolving in 3 months.

 

NICE guidelines recommend

  • Watchful waiting for 3 months with Valsalva manoeuvre (i.e. blowing up balloons with nose)
  • Grommets +/- adenoidectomy is recommended in hearing loss for >3months, speech and language delay, craniofacial abnormalities and recurrent AOM with OME
  • Hearing aids
  • Antibiotics, steroids and decongestants have no benefit in OME.

 


Complications

The complications of acute otitis media include:

  • Acute Mastoiditis (see below)
  • Sensorineural and conductive hearing loss
  • CSOM and cholesteatoma
  • Facial Nerve Palsy
  • Bacterial Meningitis
  • Neck and intracranial abscesses
  • Sigmoid sinus thrombosis

 

Acute mastoiditis is a rare complication of AOM where continued inflammation of the mucosa of the middle ear and mastoid leads to a mastoid abscess. The condition presents with similar symptoms to AOM in addition to:

  • Mastoid pain and tenderness
  • Fluctuant erythematous retro-auricular swelling
  • Auricle proptosis (abnormal protrusion of the pinna).

 

Mastoiditis is an ENT emergency and management includes:

  • CT scan of temporal bone and brain
  • Intravenous antibiotics and fluid resuscitation
  • Analgesia and antipyrexial agents
  • If failure to improve may require surgical intervention by incision and drainage +/- cortical mastoidectomy +/- grommets
Mastoiditis

Figure 4: Erythematous swelling with loss of post-auricular sulcus in keeping with acute mastoiditis. 4

 


References/Further Reading

  1. National Institute for Health and Care Excellence. (2008). Respiratory tract infections (self-limiting): prescribing antibiotics (NICE Clinical guideline [CG69]). Retrieved from https://www.nice.org.uk/guidance/cg69
  2. National Institute for Health and Care Excellence. (2018). Otitis media (acute): antimicrobial prescribing (NICE guideline [NG91]). Retrieved from https://www.nice.org.uk/guidance/ng91
  3. Probst, Grevers. Iro (2017). Basic Otorhinolaryngology: A step by step learning guide. Thieme Medical Publishers, New York.
  4. Wald (2018). Acute otitis media in children: Diagnosis. In Edwards & Isaacson (Ed.), Retrieved January 31, 2019, from https://www.uptodate.com/contents/acute-otitis-media-in-children-diagnosis
  5. Warner, Burgess, Patel, Martinez-Devesa & Corbridge (2009). Oxford Specialist Handbook of Otolaryngology and Head and Neck Surgery. Oxford University Press, Oxford.

 

Figures

  1. Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. Reproduced under creative commons licence.
  2. B. Welleschik [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], from Wikimedia Commons
  3. By Michael Hake MD (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons
  4. B. Welleschik [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], from Wikimedia Commons

Editor

Dr Thomas Finnerty

Paediatric Lead


 

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