Acute otitis media is extremely common in young children, with around half of children having three or more episodes by the age of 3 years.

Pathophysiology

• whilst viral upper respiratory tract infections (URTIs) typically precede otitis media, most infections are secondary to bacteria, particularly Streptococcus pneumonaie, Haemophilus influenzae and Moraxella catarrhalis
• viral URTIs are thought to disturb the normal nasopharyngeal microbiome, allowing bacteria to infect the middle ear via the Eustachian tube

Clinical features and diagnosis

Features

• otalgia
  • some children may tug or rub their ear
• fever occurs in around 50% of cases
• hearing loss
• recent viral URTI symptoms are common (e.g. coryza)
• ear discharge may occur if the tympanic membrane perforates

Possible otoscopy findings:

• bulging tympanic membrane → loss of light reflex
• opacification or erythema of the tympanic membrane
• perforation with purulent otorrhoea
• decreased mobility if using a pneumatic otoscope

Whilst guidelines vary, the majority use the following criteria to diagnose otitis media:

• acute onset of symptoms
  • otalgia or ear tugging
• presence of a middle ear effusion
  • bulging of the tympanic membrane, or
  • otorrhoea
  • decreased mobility on pneumatic otoscopy
• inflammation of the tympanic membrane
  • i.e. erythema