Middle ear effusion is the accumulation of fluid behind the eardrum.

Human ear is divided into three parts; the outer ear, the middle ear and the inner ear.

The middle ear is a small cavity filled with air and it contains several important structures such as ossicles and facial nerve (cranial nerve VII). It is connected to the nasopharynx via eusthasian tube which allows ventilation of the middle ear. The eardrum, also known as tympanic membrane, separates the middle ear from the outer ear.

The main function of middle ear is to transmit sound wave from the outer ear to the inner ear. It magnifies the sound intensity and converts it into electrical impulses. Effusion in the middle ear will disturb the transmission of sound, causing conductive hearing loss. This condition is known as otitis media with effusion (OME). It can either occur in one or both ears.

OME is common in children. The prevalence of OME in preschool children is 18% according to a study.

Children with craniofacial anomalies, cleft palate and Down syndrome are more prone to OME. A research conducted in this country reported that the incidence of OME in children with cleft palate is 57.6%.

OME can occur in adult, though it is less common. If OME occurs in one side of the ear, a thorough nose examination should be performed to exclude any tumour of the nasopharynx.

Etiology

Causes of middle ear effusion are:

1. Acute suppurative otitis media (ASOM). Fluid can accumulates in the middle ear following ASOM despite adequate treatment given.
2. Eusthasian tube dysfunction. May be as a result of cleft palate or tumour of the nasopharynx.
3. Upper respiratory tract infection

Studies have shown that children who were exposed to cigarette smoke, not breastfed, having nasal blockage and craniofacial abnormalities, such as cleft palate and Down’s syndrome, are at higher risk of developing middle ear effusion.

Sign and Symptoms

The main presentation of middle ear effusion is reduced hearing. In children, they often seen turning up the volume of the television louder than usual.

Many international and local studies reported that children with middle ear effusion have poor academic performance. Hearing impairment can significantly interrupts learning process at school.

Children with middle ear effusion could have problem with balance, speech and difficulty to concentrate.

Recurrent ear pain due to middle ear infection also may suggest middle ear effusion.

Clinically, doctors can identify middle ear effusion by examining the ear using otoscope or microscope. The audiologists will perform a hearing test to confirm the diagnosis and measure the degree of hearing loss.

In adult, one sided middle ear effusion can present with tinnitus and unilateral loss of hearing. Thus they should be examined by otorhinolaryngologists.

Treatment

Usually, more than half of middle ear effusion in children will resolve after three months. Intranasal steroid nasal spray might help to relief symptom temporarily. Other treatments such as oral steroid, antibiotic, antihistamine, homeopathy and prolonged usage of intranasal steroid are not proven to treat middle ear effusion.

If symptoms persist after three months of watchful waiting, a minor operation can be done to drain the fluid in the middle ear. A small incision is made on the tympanic membrane and ventilation tube is inserted through the tympanic membrane to drain the fluid and allows good ventilation through middle ear.  This will improves conductive hearing loss and prevent cholesteatoma.