This article aims to provide an overview of 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.
Anatomy of the middle ear
The middleear 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 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 fewer 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 the production of mucous
Eustachian tube dysfunction preventing adequate clearance of mucous
Risk factors for AOM:
Young age, with peak incidence in first year of life
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
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 palate)
Chronic respiratory conditions including Kartagener syndrome and cystic fibrosis
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
For a comprehensive guide to otoscopy and hearing assessment, check out our guide here.
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.
Red, bulging and tender tympanic membrane
Mucopurulent discharge in acute suppurative otitis media
Dull yellow/grey tympanic membrane
Bulging with loss of cone of light reflex
Visible fluid level behind the tympanic membrane
Rinne and Weber’s tests typically 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 conversationallevel: mild-moderate hearing loss
Correctly identifies 50% or more words when said in a loudvoice: severe hearing loss
Ear swab for microbiology, culture and sensitivity (MC&S)
Audiological assessment to assess hearing loss: pure tone audiography and tympanometry
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.
Systemically well child
If a child is systemically well and not at high risk of complications:
Simple analgesia and antipyretic agents (i.e. paracetamol or ibuprofen)
Unwell child and/or at high risk of complications
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)
Otorrhoea and/or less than 2 years old with bilateral AOM
In the presence of otorrhoea or if the child is under 2 years old 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 antibiotics
NICE recommends the following antibiotic choices:
First line: amoxicillin (clarithromycin or erythromycin if penicillin-allergic).
Second line: co-amoxiclav (worsening symptoms or first choice taken for at least 2 to 3 days).
Decongestants or antihistamines have not been shown to alleviate symptoms.
Otitis media with effusion
OME is a self-limitingdisease with 50% of cases resolving in 3 months.
Watchful waiting for 3 months with Valsalva manoeuvre.
Grommets +/- adenoidectomy is recommended if hearing loss is present for greater than 3 months, language is delayed, there are craniofacial abnormalities or if there is a history of recurrent AOM with OME.
Hearing aids if significant hearing loss is identified.
Antibiotics, steroids and decongestants have no benefit in OME.
The complications of acute otitis media include:
Acute mastoiditis (see below)
Sensorineural and conductive hearing loss
Facial nerve palsy
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 may include:
CT scan of the 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
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