2.1 Definitions

Otitis media is the generic term for middle ear inflammation which can exist in an acute and chronic state and can occur with or without symptoms. Different management strategies require that this disease be classified clinically as acute otitis media (AOM) or otitis media with effusion (OME). However, these should be considered as end points in a spectrum of conditions, the distinction between which is often difficult to determine.⁷

There is no agreed universal definition of AOM. The working definition in this document is inflammation of the middle ear of rapid onset presenting most often with local symptoms (the two most common being earache and rubbing or tugging of the affected ear) and systemic signs (fever, irritability and poor sleep for example). There may be a preceding history of upper respiratory symptoms including cough and rhinorrhea (see section 2.4).

Otitis media with effusion is defined as inflammation of the middle ear, accompanied by the accumulation of fluid in the middle ear cleft without the symptoms and signs of acute inflammation. OME is often asymptomatic and earache is relatively uncommon (see section 2.4).⁸

2.2 History taking

The history and clinical assessment of children with symptoms, which may be associated with otitis media, are used to differentiate between AOM, OME and non-otological pathology.

The symptoms most associated with acute otitis media are fever, earache, irritability, otorrhoea, lethargy, anorexia and vomiting. These lack sensitivity or specificity for diagnosis particularly in children under two in which group the symptoms of earache, conjunctival symptoms and rhinorrhoea are associated with AOM.

In the case of OME, there may be no history to indicate the presence of the disease. A relevant element to be elicited in the history includes information about disability in terms of hearing difficulty, together with information on social interaction, behaviour, function in the educational setting and speech and language development. Clumsiness and poor balance may also be relevant.

A history alone is not sufficient to diagnose otitis media.

2.3 Examination techniques

The diagnosis of middle ear pathology and the ability to distinguish between AOM and OME, especially in children, can be difficult. In addition to appropriate training, otoscopy requires the use of a high quality, well illuminated otoscope. Disposable speculae for otoscopes are preferable, otherwise they should be sterilised appropriately. It has been suggested that the sensitivity of a skilled validated otoscopist in detecting the presence of middle ear fluid should be 90%, with a specificity of 80%.⁹ Clearly this level of accuracy may be difficult to achieve in general non-specialist practice. The sensitivity of otoscopy in diagnosing middle ear pathology may be increased by the use of pneumo-otoscopy, which helps in the differentiation of a healthy middle ear from one containing fluid, but this technique is not widely used in UK clinical practice. The available literature suggests that the sensitivity of pneumo-otoscopy when compared with the finding of fluid at myringotomy will range from 87%-99% with a mean of 93%. The mean specificity was 78%. These figures appear to be very similar amongst Otolaryngologists, Paediatricians and Paediatric Nurse Practitioners.¹⁰ If pneumo-otoscopy is to become part of routine practice in the UK, this will have to involve the training of practitioners.

2.4 Diagnosis

2.4.1 DIAGNOSIS OF AOM

Acute otitis media is a purulent middle ear process and, as such, otoscopic signs and symptoms consistent with a purulent middle ear effusion in association with systemic signs of illness are required.^{11, 12, 13, 14, 15, 16} Ear related symptoms may include earache, tugging or rubbing of the ear, irritability, restless sleep and fever. Children may also have a history of cough and rhinorrhea, symptoms which are reported to increase the risk of AOM.¹¹ Earache, however, is the single most important symptom. Evidence level 2+,3,4

Otoscopic appearances typical of AOM include bulging tympanic membrane with loss of the normal landmarks, change in colour, (typically red or yellow) and poor mobility.¹³ Evidence level 2+

Systemic signs of illness with a middle ear effusion are not sufficient to make the diagnosis, and similarly, neither is the finding of an incidental effusion in an otherwise well patient.

It should be borne in mind that the typical symptoms and signs (see Table 1) may have resolved by perforation of the tympanic membrane and discharge of pus.¹⁶ Additionally, AOM may leave a middle ear effusion for a variable period of time following resolution of the acute symptoms - the two forms of otitis media should be considered part of a disease continuum.^{7, 17, 18} Evidence level 1+,4

2.4.2 PRESENTATION PATTERNS FOR CHILDREN WITH OME

Most children have middle ear effusions at some time during childhood but these are transient in the majority and often asymptomatic.¹⁹ There is a minority in whom effusions persist over months or years causing hearing loss which in turn potentially impairs speech development and educational performance.^{20, 21} Evidence level 4

Boys are more susceptible to OME than girls, as are children in day care and those with older siblings.²² Rates of bilateral OME are twice as high during winter than summer.²³ Common cold and OME are the most frequent diseases of infancy, characterised by a multifactorial pathogenesis.²⁴ There is an association between OME and respiratory infections²⁵ and there is likely to be a causal relationship between parental smoking and both acute and chronic middle ear disease in children.^{22, 26, 27} Newborns in neonatal intensive care units have a high incidence of OME, which is also more prevalent in the first than second year of life.²⁸ Evidence level 2++,2+,4

Some case control studies have shown that balance problems are significantly worse in children with persistent OME than in healthy children.^{29, 30} Other studies do not show these associations.^{31, 32, 33, 34} Evidence level 2+,3,4

Healthcare professionals should have an increased awareness of the possibility of the presence of otitis media with effusion in asymptomatic children. The following groups of children are at particular risk: those in day care those with older siblings those with parents who smoke those who present with hearing or behavioural problems.

Otitis media with effusion may lead to a variable group of behavioural symptoms including clumsiness, inattentive behaviour, and speech or language development difficulties.

The evidence shows that there is only a weak association between OME in early life and slowed speech and language development in children under four years of age. Similarly, only a weak association between early OME and delay in expressive language development has been demonstrated.^{32, 35} Evidence level 2++,2+

More research is needed to show whether persistent OME causes language delay and/or behavioural problems, and whether early intervention is indicated.

2.4.3 DIAGNOSIS OF OME

In many studies OME is diagnosed if there is middle ear effusion on pneumatic otoscopy with no signs of acute inflammation. In practice, pneumatic otoscopy is not used in primary care. No evidence based studies were identified concerning the most commonly used primary care diagnostic tool - otoscopy (with or without tuning fork testing).

Evidence of middle ear effusion consists of the presence of either:

• at least two tympanic membrane abnormalities (abnormal colour such as yellow, amber,or blue; opacification other than due to scarring; and decreased or absent mobility) and/or
• otoscopy typically showing a retracted/concave tympanic membrane with a colour change (typically yellow or amber). Air bubbles or an air/fluid level may be present and, while not typical, fullness or bulging may be visualised. Pneumo-otoscopy will demonstrate reduced or absent mobility.

The main symptom associated with OME is hearing loss (see Table 1). However this hearing loss is often not identified in infants and young children.⁷ Evidence level 4

Table 1: Diagnostic features of AOM and OME

In most situations, the GP will have to depend on history and otoscopy for diagnosing otitis media.

2.5 Audiological evaluation

2.5.1 AUDIOMETRY

Where audiometry is required for assessment of hearing thresholds and middle ear function (not screening) it should be carried out by suitably trained personnel, in quiet surroundings and with the correct equipment. This is a very specialised procedure and practices should adhere to specific criteria regarding staff training, room size and background noise levels to guarantee accuracy. If GPs wish to conduct audiological evaluation within the surgery setting, they should have the appropriate equipment and suitably trained staff. This can be expensive and time consuming, so such cases may be better referred to a local Community Audiology Clinic or to a local hospital otolaryngology (ENT) outpatient department.

2.5.2 TYMPANOMETRY

Tympanometry is a very useful tool for diagnosis but is rarely used in the primary care setting in the UK.

Children who require hearing loss assessment should be referred to an audiologist.