The child should not unnecessarily be labelled as a ”chronic ear patient”. Wrong and uncertain diagnoses result in unnecessary courses of antibiotics and tympanostomy tube insertions.
Acute otitis media (AOM) is an infectious disease associated with a respiratory tract infection or a common cold. A bulging tympanic membrane is the most reliable sign of bacterial infection of the middle ear. In a child with no symptoms of infection, AOM is highly unlikely.
Pneumatic otoscopy and tympanometry Tympanometry provide indirect information on the presence of effusion, considerably improving the diagnostic accuracy.
Definition
In lay language, "ear infection" conventionally means acute otitis media (AOM). A physician, however, should define the disease more accurately, as ‘ear infection' may also mean other conditions, such as external otitis.
The spectrum of findings associated with the tympanic membrane and middle ear is wide. Of these, it is essential to recognize AOM, otitis media with effusion (OME) and chronic OME ("glue ear", with effusion persisting for more than 3 months), and it should be borne in mind that OME alone is not an indication for antibiotics.
The criteria for acute otitis media (AOM)
Symptoms of acute infection
Middle ear effusion
Infectious tympanic membrane findings
Bulging is the most reliable sign of bacterial infection.
Other typical findings include a cloudy, yellowish tympanic membrane with displaced or absent light reflex.
Redness alone is not a diagnostic finding.
OME means that there is secretion in the middle ear in the absence of AOM.
The tympanic membrane is typically either normally concave or retracted.
Effusion may be visible behind the tympanic membrane (as a fluid level, for example). Cloudiness of the tympanic membrane may be due to either effusion behind it or to thickening of the tympanic membrane.
OME is very common, because effusion in the middle ear is present in as many as one in four infants during a common cold and always (for 2 weeks to 3 months) after AOM.
"Glue ear" (chronic OME) means that there has been effusion in the middle ear for more than 3 months Otitis Media with Effusion (Glue Ear). A child may also have symptoms of acute infection in association with ‘glue ear'.
Symptoms
A diagnosis of AOM cannot be made on the basis of symptoms Unspecific Symptoms of Acute Otitis Media but, on the other hand, AOM cannot be diagnosed in the absence of symptoms.
As "asymptomatic otitis media" is not AOM, antibiotics are not indicated.
AOM does not cause any specific symptoms. It is difficult to evaluate otalgia in a small child and pulling at the ears, for example, is also common during a common cold. Analgesics should be given if otalgia is even suspected.
Hearing is impaired due to middle ear effusion.
Clinical examination
Tympanometry Tympanometry in the Diagnosis of Acute Otitis should be performed before otoscopy and before cleaning the ear canal, whilst the child sits comfortably on the parent's lap. A tympanogram obtained whilst the child is struggling is rarely reliable. See tympanometry Tympanometry.
When the ear is being inspected, an adult should hold the child securely on his/her lap and restrain the child's head; this way the examination will not be painful.
The minimum equipment for diagnosis consists of a powerful pneumatic otoscope able to create an airtight seal and several specula of varying sizes. A reasonably priced operating otoscope head, which is easy to attach to the otoscope handle, should also be available to enable the removal of cerumen under direct vision.
Cerumen should be removed from the ear canal.
It is essential that the examiner is able to recognise the tympanic membrane landmarks (manubrium of malleus, umbo, light reflex).
The position, translucency, colour and mobility of the tympanic membrane must be observed.
Findings
The spectrum of findings associated with the tympanic membrane and middle ear is wide.
AOM should be distinguished from other situations where there is effusion in the middle ear .
It should be borne in mind that middle ear effusion alone is not an indication for antibiotics.
The position of the tympanic membrane is a central criterion in differential diagnosis.
A bulging tympanic membrane is specifically associated with an acute bacterial inflammation.
As the ear heals the tympanic membrane becomes either concave, which is the normal position, or retracted.
"Glue ear" is typically associated with a retracted tympanic membrane.
Middle ear effusion can be detected based on a fluid level or air bubbles, by tympanometry Tympanometry or by using a pneumatic pump, as necessary, if it is not otherwise clear whether there is effusion.
References
Blomgren K, Pitkäranta A. Current challenges in diagnosis of acute otitis media. Int J Pediatr Otorhinolaryngol 2005 Mar;69(3):295-9. [PubMed]
Bluestone CD, Klein JO. Otitis media in infants and children. 4th edition. Hamilton, Canada, BC Decker, 2007.
Laine MK, Tähtinen PA, Ruuskanen O, Huovinen P, Ruohola A. Symptoms or symptom-based scores cannot predict acute otitis media at otitis-prone age. Pediatrics 2010 May;125(5):e1154-61 [PubMed]