Otitis Media | Simple Revision Notes for Medical Students

The Eustachian tube connects the middle ear to the nasopharynx. It is crucial for draining middle ear secretions, as well as allowing equalisation of pressure.
Otitis media is usually preceded by a viral upper respiratory tract infection. This can result in inflammation and oedema of various structures, including the nasal mucosa and nasopharynx.
Ultimately, this causes Eustachian tube dysfunction and can result in a negative pressure forming in the middle ear.
This negative pressure essentially pulls bacterial/viral pathogens into the middle ear from the nasopharynx.
Furthermore, any blockage of the Eustachian tube i.e. secondary to an infection, can result in fluid stagnating in the middle ear which subsequently is more prone to becoming infected.
Additionally, these preceding viral infections can alter the mucosal immunity and changing surface antigens that encourage adherence of bacteria.
Children, particularly those <1 year, have shorter, more horizontal, and wider Eustachian tubes, increasing their risk of developing otitis media.

Lars Chittka; Axel Brockmann, CC BY 2.5 , via Wikimedia Commons

Middle Ear Anatomy

Craniofacial abnormalities that result in Eustachian tube dysfunction e.g. cleft palate
Down’s syndrome: Due to abnormal mucosa and reduced immunity
Primary ciliary dyskinesia: Due to reduced mucus clearance
Tobacco smoke exposure
Bottle feeding (breastfeeding is protective)
History of atopy
Day care attendance: Due to increased infection risk
Family history

Bacterial causes: The following microbes account for approximately 95% of otitis media
- Streptococcus pneumoniae
- Haemophilus influenza
- Moraxella catarrhalis
- Streptococcus pyogenes
Viral causes: Influenza, rhinovirus, RSV, adenovirus

Otalgia
Rubbing/pulling of the ear
Fever
Change in behaviour: Otitis media is more common in younger children/babies, so symptoms may be less specific. For example:
- Reduced feeding
- Restlessness
- Crying
Otoscopy
- Bulging of the tympanic membrane
- Erythematous/cloudy/yellow tympanic membrane
- Acute suppurative otitis media:
  - You may be able to see an air-fluid level behind the tympanic membrane.
  - Patients might complain of increasing pain in the ear, followed by discharge – this usually happens where there has been a perforation of the tympanic membrane.
  - Patients might feel a pop when this occurs.

Otitis externa: Will not involve the tympanic membrane, and the external auditory canal will be the main site of pathology.
Myringitis: Erythema and vessel injection of the tympanic membrane only i.e. inflammation of the tympanic membrane alone. The middle ear is unaffected here.
Otitis media with effusion: Also known as glue ear – a chronic condition without signs of acute infection.

Admission

Patients with severe infection and systemic involvement.
People with complications of otitis media.
<3 months with temperature >38 (can consider admission in patients <3 months or patients 3-6 months with temperature >39).

Conservative

Analgesia
Safety-netting: Not all patients require antibiotics, so safety-netting with regards to worsening symptoms, systemic involvement, or no symptom improvement after 3 days is important (the usual course of otitis media is 3 days but it can last for 1 week)

Medical

Oral antibiotics
- First line: 5-7 days amoxicillin, or clarithromycin/erythromycin in patients who are penicillin allergic.
- Second line: 5-7 days of co-amoxiclav if patients have no symptom improvement within 2-3 days of taking the first-line antibiotic.

Facial nerve palsy
Tinnitus
Otitis media with effusion
Mastoiditis: Infection of the mastoid air cells - these patients will be very unwell and present with a boggy swelling of the mastoid process.
Meningitis
Intracranial abscess

Also known as glue ear; occurs when the middle ear becomes fluid filled. In this scenario, there are no signs or symptoms of acute infection/inflammation.
It results in hearing loss.
On examination, the ear drum may have an abnormal colour, and it is possible to see bubbles or an air-fluid level as well. The ear drum may also be retracted, as opposed to bulging.
Initially, patients can be monitored for a 3-month period, as OME can often resolve on its own.
Hearing aids may be offered to patients with bilateral OME and hearing loss, if surgery is not possible/contraindicated.
The surgical intervention for OME is a myringotomy (creating a small hole in the ear drum), followed by the insertion of grommets – these are small tubes that allow air to pass into the middle ear and equalise pressures.
Grommets (tympanostomy tubes) fall out on their own and the tympanic membrane self-heals.

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