Acute otitis media (AOM) – a middle ear infection – is a common problem and accounts for many pediatric antibiotic prescriptions.
The middle ear infection is defined by;
(1) bulging of the tympanic membrane (which may be moderate or severe) or;
(2) new onset of otorrhea not due to otitis externa accompanied by acute signs of illness and signs or;
(3) symptoms of middle ear inflammation.
- Acute otitis media (AOM): is an infection of the middle ear caused by bacteria or viruses.
- Acute suppurative otitis media (OM): the presence of pus in the middle ear. It is a subtype of AOM. And in around 5% of cases, the eardrum perforates.
- Mild symptoms: middle ear pain for <48 hours and temperature < 39 degrees celsius.
- Severe symptoms: moderate or severe ear pain for > 48 hours, or temperature > 39 degrees celsius and bilateral AOM in children < 24 months of age.
- Otitis media with effusion (OME): OME is a chronic inflammatory condition without acute inflammation, which often follows a slowly resolving AOM. There is an effusion – that is a glue-like fluid behind an intact tympanic membrane in the absence of signs and symptoms of acute inflammation.
- Chronic suppurative otitis media (CSOM): CSOM is a long-standing suppurative (i.e., pus-forming) middle ear inflammation, usually with a persistently perforated tympanic membrane.
- Mastoiditis: is an acute inflammation of the mastoid periosteum and air cells occurring when an AOM infection spreads out from the middle ear.
- Cholesteatoma: occurs when keratinising squamous epithelium (skin) is present in the middle ear as a result of tympanic membrane retraction.
Acute otitis media, i.e., AOM ear infection, is more common in boys than girls and occurs in all ages but is most prevalent between 6 and 24 months of age, after which it begins to decline. Acute otitis media is infrequent in school-age children and adolescents.
Children who have early-onset of AOM ear infections (i.e. before the age of 6 months) are at increased risk of recurrent AOM. Children who have fewer or no episodes of AOM before three years are unlikely to have subsequent severe or recurrent AOM.
Middle ear location
The middle ear cavity is between the external ear canal and the inner ear that contains the ossicular chain, i.e., incus, malleus and stapes. The facial nerve traverses the (medial) wall of the middle ear. The middle ear is contiguous (; shares a common border or continuous with) the Eustachian tube, attic (epitympanum), and mastoid air cells.
The tympanic membrane is divided into four quadrants:
The pars flaccida is the small portion of the tympanic membrane above the lateral process of the malleus; it is thicker and less taught than the rest of the tympanic membrane. The remainder of the tympanic membrane (pars tensa) is thinner than the pars flaccida and is suspended from the fibrous tympanic annulus.
The normal ear is aerated, and the normal tympanic membrane is intact, slightly convex, translucent and mobile.
Pathogenesis & risk factors of acute otitis media ear infection
Risk factors for otitis media ear infection
Ageis the most important risk factor for AOM. As such, AOM most commonly presents between 6 and 12 months of age. After that, the rate declines with age, with a small increase between 5 to 6 years (school entry age). AOM is not common in school children and adolescents.
Other risk factors for AOM include:
- Immature anatomy (e.g. in infants, the Eustachian tube Is shorter, more floppy and more horizontally positioned than in adults, permitting nasal secretion to enter the middle ear easily)
- Genetic predisposition
- Family history: family history of AOM is a risk factor for AOM, especially among children who have siblings
- Daycare centres
- Tobacco smoke and air pollution
- Race and ethnicity: Native Americans, Alaskan & Canadian Inuit children and indigenous Australian and Greenlander children have a higher risk than European descent
- Lack of access to medical care: increased risk of suppurative episodes of otitis media
- Season: AOM increases in the winter months
- Altered host defences: HIV, cleft palate. The Cleft palate is a risk factor because of incorrect insertion of the tensor veli palatini muscle in the soft palate, which results in the inappropriate opening of the eustachian tube on swallowing or wide mouth opening. And thus, a functional obstruction of the tube results. Other risk factors include; down syndrome and allergic rhinitis.
- A lack or low levels of breastfeeding increases the risk of AOM. This is because breastfeeding protects against AOM during the first two years of life. And thus, any breastfeeding is better than none. Furthermore, breastfeeding reduces colonisation of the nasopharynx by bacterial otopathogens (e.g. Streptococcus pneumoniae, nontypeable Haemophilus influenzae).
The middle ear is a small chamber within an air-filled system that includes the nares, Eustachian tube, and mastoid air cells. The respiratory mucosa lining the system is highly permeable; changes in one place are generally reflected throughout the whole system as a result of events affecting other areas. Mastoiditis, labyrinthitis, petrositis, meningitis, and lateral sinus thrombosis.
The following events occur in the pathogenesis of AOM in at-risk children:
Step 1: The patient has an antecedent event (usually a viral upper respiratory tract infection) while colonised with an otopathogen(s). Some evidence suggests that co-colonisation with bacterial pathogens may trigger the cascade of events in the absence of viral respiratory infection.
Step 2: The event results in inflammatory oedema of the respiratory mucosa of the nose, nasopharynx, and Eustachian tube.
Step 3: Inflammatory oedema obstructs the narrowest portion of the Eustachian tube (the isthmus).
Step 4: Poor ventilation and negative middle ear pressure lead to obstruction of the isthmus. Thus, the accumulation of secretions is produced by the middle ear mucosa.
Step 5: Viruses and bacteria that colonise the upper respiratory tract enter the middle ear via aspiration, reflux, or insufflation.
Step 6: In the middle ear, microbial growth leads to secretions which often progresses to producing the clinical signs of acute otitis media, i.e., bulging tympanic membrane [TM], middle ear fluid, erythematous tympanic membrane.
Step 7: The middle ear effusion may persist for weeks to months following sterilisation of the middle ear infection.
S. pneumoniae; Accounts for 15-25 %. And symptoms are more severe, i.e., high fever, intense otalgia and the potential for complications such as bacteremia and mastoiditis.
Nontypeable H.influenzae (NTHi); Accounts for 50-60 % and is more commonly isolated in bilateral than unilateral AOM. It is also associated with concurrent conjunctivitis and milder symptoms, e.g. lower fever and less inflamed tympanic membrane. However, it is associated with an increased risk of treatment failure and recurrence despite appropriate antibiotic therapy and chronicity.
Moraxella catarrhalis; Accounts for approximately 12-15 % of bacterial middle ear isolates in children with AOM.
Group A streptococcus; Accounts for 2-10% and is more common in older children and more frequently associated with local complications (e.g. tympanic membrane perforation, mastoiditis) and less frequently fever and systemic or respiratory symptoms than AOM caused by other organisms.
Staphylococcus aureus; Uncommon cause of AOM
Viral pathogens; RSV, picornaviruses, coronaviruses, influenza viruses, adenoviruses.
Mixed bacterial and viral co-infection; Has clinical implications because patients may respond differently to antibiotic therapy. The presence of viruses may increase middle ear inflammation, decrease neutrophil function, and reduce antibiotic penetration into the middle ear.
Sign, symptoms & clinical presentation
Symptoms include combinations of the following:
- Ear pain, ear rubbing, hearing loss and ear drainage
- Fever occurs in one to two-thirds of children with AOM, though temperature >40 degrees celsius is unusual without bacteremia or another focus of infection.
- Ear pain is the most common complaint and best indicator of AOM (however, not always present)
- Infants may present with non-specific symptoms and signs (e.g. fever, fullness, disturbed or restless sleep, poor feeding/anorexia, vomiting, diarrhoea.
- Symptoms of AOM may overlap with those of upper respiratory tract infection without AOM or may be subtle or absent.
Physical examination findings
Otoscopy is crucial (make sure the cerumen does not disrupt your view)
Assessment of the tympanic membrane
Each quadrant should be assessed systematically to evaluate position, mobility, translucency, colour and other findings.
1. Tympanic membrane findings may include:A bulging TM
Bulging(a hallmark of inflammation and differentiates middle ear effusion from AOM. It indicates both inflammation and MEE), opaque, yellow or white. Bulging (83-99% predictive value) is more common in the posterosuperior quadrant. When the tympanic membrane (TM) is bulging, the handle of the malleus is obscured. The TM may appear full rather than bulging when there are smaller amounts of infected middle ear fluid.
2. A retracted TM
This suggests a Eustachian tube dysfunction
3. Acute perforation with purulent otorrhea:
This establishes the diagnosis of AOM provided Otitis externa (OE) is ruled out. The colour of an infected TM may be white or pale yellow. And this usually indicates pus in the middle ear cavity, which is a sign of AOM.
It is important to remember that middle ear fluid that is not infected (i.e., OME) usually appears amber, grey, or blue. Conversely, a red or hemorrhagic TM may indicate acute inflammation, but these findings are non-specific because they could be caused by crying or high fever.
Other findings; Bullae, bubbles, myringosclerosis, perforation
Diagnosis of AOM
Acute otitis media – AOM
- Middle ear effusion with acute signs of middle ear inflammation
- Bulging tympanic membrane +/- perforation
- White or pale yellow, perforation with purulent otorrhea
Bulging of TM or signs of acute inflammation (e.g. marked erythema of the TM, fever, ear pain) are all signs which suggest AOM. Although in the early stages, you may not get the bulging of the TM.
Middle ear effusion – MEE
Abnormal colour (white, amber, grey or blue) of the TM. But no bulging. Although it may be red or retracted and in a neutral position
Other symptoms may include conjunctivitis (otitis-conjunctivitis), which is usually caused by Haemophilus influenzae.
The clinical course of AOM
Systemic and local signs and symptoms of AOM usually resolve within 72 hours. Symptoms and signs resolve more slowly in children who are managed with analgesia and observation than those who were prescribed appropriate antibiotic therapy.
Persistence of middle ear effusion after the resolution of acute symptoms is common.
- Otitis media with effusion (OME)
- Otitis externa
1. Hearing loss: Conductive hearing loss is common due to the fluid being in the middle ear and preventing the tympanic membrane and ossicles from functioning properly. The hearing loss is comparable to having earplugs in the ear. Fluid may persist for weeks to months after the onset of signs of AOM. However, sensorineural hearing loss is uncommon.
2. Balance and motor problems: Children may have balance, motor or vestibular problems related to vestibular dysfunction. Dizziness and vertigo with or without tinnitus or nystagmus may be related to labyrinthitis, mastoiditis or cholesteatoma.
3. Cranial nerve palsies (facial nerve, abducens nerve) may be related to acute mastoiditis, petrositis, cholesteatoma, or intracranial complications.
4. Tympanic membrane abnormalities:
Perforation; can result in central ischemia, necrosis, and spontaneous perforation of the TM, usually accompanied by otorrhea.
Myringosclerosis;This is calcification of connective tissue and is a complication of frequent middle ear disease. It is characterised by whitish plaques in the TM and occasionally in the middle ear.
Retraction or collapse: Chronic or recurrent decreased pressure in the middle ear in children with recurrent AOM may lead to retraction or collapse of the TM.
Chronic suppurative otitis media: This is defined as perforation of the TM with chronic purulent drainage from the middle ear cleft for more than six weeks. Or perforation without drainage for three months or longer needs a referral.
Cholesteatoma: This is an abnormal growth of the squamous epithelium in the middle ear and mastoid regions that progressively enlarge to surround and destroy the ossicles. Recurrent AOM may lead to retraction pockets in the TM, and this is a risk factor for cholesteatoma. Clinical features include a white mass behind the TM, focal granulation at the periphery of the TM, new-onset hearing loss, and ear drainage for more than two weeks despite treatment.
Mastoiditis: Most episodes of AOM are associated with some inflammation of the mastoid bone because the mastoid air cells are connected to the distal end of the middle ear through a small canal or antrum. Postauricular swelling and protrusion of the auricle
- Facial nerve paralysis
- Brain abscess
Treatment of otitis media
Pain is a common feature of AOM and may be severe. Therefore consider treatment of the pain with ibuprofen or paracetamol.
Decongestants & antihistamines (can prolong middle ear effusion)
Olive oil, herbal extracts
Antibiotic therapy versus observation
In addition to pain control, there are two strategies for initial management of AOM
1. Immediate treatment with antibiotics
2. Observation with the initiation of antibiotics therapy if the symptoms and signs worsen or fail to improve after 48 to 72 hours
The choice of strategy depends on the age of the child, the severity of illness and parental preference:
< 6 months of age with AOM treat with antibiotics. Febrile infants who are younger than six months should be referred
Six months to 2 years with unilateral or bilateral AOM: treat with antibiotics
Six months to 2 years with unilateral AOM: you may observe and wait
Treat children greater than two years who appear toxic have persistent otalgia for more than 48 hours and have a temperature > 39 degrees Celcius in the past 48 hours. Also, consider treating children who have bilateral AOM or have uncertain access to follow up.
For children greater than two years who are normal hosts with mild symptoms and signs and no otorrhea, initial observation may be appropriate.
When considering prescribing antibiotics, the following should be kept in mind:
- Clinical & microbiological efficacy
- Acceptability (taste, texture)
- Absence of side effects and toxicity
- The convenience of the dosing schedule
1. No recent beta-lactam therapy (within 30 days), no concomitant purulent conjunctivitis, and no history of recurrent AOM
Amoxicillin (90mg/kg divided into two doses) if < 2 years than ten days and those > 2 years for 5 to 7 days
2. Recent beta-lactam therapy, concomitant purulent conjunctivitis or history of recurrent AOM unresponsive to amoxicillin
Co-amoxiclav if < 2 years for 10 days and those > 2 years for 5 to 7 days
3. Treatment of otitis media in adults with penicillin allergy
Azithromycin, clarithromycin or clindamycin
4. AOM with perforation
Oral antibiotics such as amoxicillin
5. Initial observation
> 2 years of age who are normal hosts (e.g., immune-competent, without craniofacial abnormalities), without otorrhea, and who have mild symptoms and signs of unilateral AOM.
Follow up patients
Children who fail to improve after 48-72 hours of antibiotic therapy should be seen during follow up to confirm AOM and evaluate other causes of symptoms.
If no antibiotics are given, then treat with antibiotics
See children < 2 years of age eight to ten weeks after diagnosis
Children > two years who have language or learning problems be seen 8 to 12 weeks after diagnosis
Children > 2 years who are without language or learning problems should also be followed up
The tympanic membrane tends to heal within hours to days, and pain should reduce. If the pain does not subside, then consider another diagnosis, e.g. mastoiditis
Perforation greater than three months or longer should be referred
Treatment failure (lack of improvement in symptoms by 48 to 72 hours)
Try co-amoxiclav if not treated with this already or if tried already, then levofloxacin
Defined as signs and symptoms of AOM within 30 days after completion of successful treatment. If within 15 days use IV antibiotics
Evaluate the immune system if children have >4 episodes of AOM within 12 months.
Children should stay awake during descent and chew gum or food.
Otitis media in adults treatment guidelines
Refer to the National Institute for Health and Care Excellence (NICE) guidelines
Treatment of chronic otitis media in adults
This usually requires referral to an ear, nose and throat (ENT) specialist. On assessment, usually, antibiotics and steroid drops are prescribed.
Antibiotic treatment of otitis media in adults
Treatment involves the use of penicillin and sometimes a combination of drugs such as co-amoxiclav.
Treatment of serous otitis media in adults
Referral to a specialist is usually required, and they may prescribe the following:
- Steroids and decongestants
Is otitis media common in adults?
More common in children. However, the incidents have been reported at 0.25% per annum in adults.
How to prevent otitis media in adults
Otitis media is not common in adults. However, prevention strategies that are common include; (1) removal of risk factors (mentioned above) ; (2) Medication, i.e., antibiotic prophylaxis where necessary; and finally, (3) surgical intervention, i.e., insertion of grommets.
is otitis media curable?
Yes. This may include the use of antibiotics, or if the cause is viral, then with time, it should clear up.
History taking in earache for pharmacists example.
Getting started with history:
Let the patient tell the story
- time course of the ear pain; is it chronic, i.e., months, years or acute?
- associated symptoms
- aggravating factors
- Pain unresponsive to simple analgesics or that is burning or lancinating in quality may be nerve related.
The three factors above allow you to distinguish between numerous causes of ear pain.
Note: You must differentiate between acute and sub-acute ear pain from chronic and remove ear wax before diagnosis
OM produces severe pain and can affect night sleep
- Presence of URTI suggests OM or serous otitis
- Age: children with ear pain, most commonly acute OM
Referred pain from malignancy:
- Present for some time, usually more than a month
- Typically, in older patients
Necrotizing (malignant) external otitis
- External otitis progresses to invade the temporal bone and adjacent structures
- Common in older diabetic, immunocompromised.
- Consider when the patient does not respond promptly to treatment for otitis externa
- Patients over 50 years reporting acute or subacute onset of headache, pain in the temporal area or scalp tenderness
- Specific symptom is jaw claudication: pain in the proximal jaw near the temporal mandibular joint (TMJ) brought on or aggravated by a brief period of chewing and relieved by resting in the jaw.
- Prompt treatment otherwise blindness.
Common in children when OM spreads to the mastoid air cells behind the ear.
- Fever, postauricular swelling, tenderness, and erythema which can push the ear with mass effect
- Must be promptly recognised as patients report becoming ill several weeks before improving but then developing fever and signs of local infection. Infection can destroy temporal bone and meninges and penetrate the brain.
History of presenting complaint
Tell me about your pain?
Was the ear pain preceded by an upper respiratory tract infection (UPRI)?
- 10 days or less: OM or serous otitis
- 10 days or more: Mastoiditis
Few weeks: referred pain
Severe pain at the time of air travel or diving underwater? Barotrauma
Where is the pain?
How long have you had the pain?
Describe how the ear pain feels?
- Severe, deep within the ear? OM
- Like pressure or a clogged feeling? Ear wax, Eustachian tube dysfunction (serous otitis)
- Burning, knife-like or tingling? Neuralgia (trigeminal, glossopharyngeal, or cervical nerve root?)
- Bilateral? Otitis externa, gastro oesophagal reflux disease (GORD), TMJ dysfunction
What makes the pain worse?
- Chewing? Temporal arteritis
- Arthritis of the neck (referred pain from C2, C3 radiculopathy)
Does ear pulling worsen pain?
Is the pain worse with swallowing?
- Elongated styloid process
Pain worse in the morning?
- TMJ dysfunction or GORD
Is the pain worse with hot or cold foods?
- Infected 3rd molar
Was pain provoked by light touch?
What other symptoms do you have?
- Fever? AOM or mastoiditis
Do you grind your teach
- Perforated eardrum or otitis externa
Pain decrease after discharge began?
- Perforated eardrum from OM
- Eustachian tube dysfunction (serous otitis)
Crackling or gargling sounds in the affected ear?
- Eustachian tube dysfunction (serous otitis)
Itch as well as pain?
- OE or psoriasis or seborrhea
Allergies or hay fever?
- Serous otitis
Do you use Q-tips or other objects to clean your ears?
- Otitis externa
What treatment have you tried?
Past medical history
Diabetic? On chemotherapy?
Skin conditions such as psoriasis or seborrheic dermatitis?
- Otitis externa
Is anyone else in the family unwell?
Any allergies to medication and food?
Do you swim?
- Otitis externa
Have you been scuba diving?
Review of symptoms
Weight loss: tumours?
Persistent ear pain with discharge worse at night: Necrotising malignant external otitis?
Pain near the ear with chewing in a patient over 50 years: Temporal arteritis
Pain and swelling behind the ear with recent URTI or ear infection: Mastoiditis