The ear, in the world of medicine, is not just the ear that we commonly refer to. The ear is quite a complex structure and consists of 3 parts: the outer ear, the middle ear and the inner ear. Otitis media, as the name suggests, refers to infection in the middle ear.

How does otitis media occur? The middle ear, which is the space behind the eardrum, is normally filled with air. A tube normally connects the middle ear to the throat. This tube is called auditory tube or the Eustachian tube (Eustachian was a chap who discovered the tube hundreds of years ago). The function of the tube is to normalize or equalize the pressure between the middle ear and the atmosphere. When blocked, pressure in the middle ear decreases, causing mucus (or fluid) to fill up the space. The mucus may then become contaminated by bacteria and viruses, thus allowing infection to occur.

This is the basic mechanism of middle ear infection. There are many reasons for the Eustachian tube to become blocked. One of the commonest being an upper respiratory infection or common cold, which causes the Eustachian tube to swell up and block. This is particularly common in children as their Eustachian tubes are smaller and not yet fully developed. The other less common cause being a tumor growing around the opening of the Eustachian tube in the throat, causing the tube to obstruct. This is particularly common in the middle age or the elderly population, where tumor of the throat is prevalent. Having said that, very often, an ear infection occurs 'out of the blue' for no apparent reason.

What are the symptoms of a middle ear infection? Earache is the most common complaints. It is often described as a deep ache or pressure, sometimes bad enough to disrupt sleep. Dulled hearing and deafness are also common symptoms; they usually last for several days. Fever is also common, but not very 'specific' as other infections can also cause fever. Young children with middle ear infections may also vomit and tend to look very ill. Babies cannot point to their pain but if they are irritable, feel hot and crying all the time, a middle ear infection should always be suspected. Discharge is a common symptom too. As the infection progresses, pressure begins to build up in the middle ear. When it is too high, the eardrum 'pops', allowing its content (usually pus) to flow out from the middle ear.

Are all earaches caused by middle ear infection? Absolutely not! Lots of other diseases can cause earaches as well. For example, people with toothache can sometimes have earaches, this is due to pain being 'referred' to the middle ear. Other causes of earache due to referred pain include sinusitis (infection of the sinus), sore throat, tongue ulcers, thyroid problems, outer ear infections, so on and so forth.

What is the treatment for a middle ear infection? The aim of treatment is to kill the bugs responsible, to control the pain and to control the fever (to bring the high temperature down to normal). Antibiotics are commonly given to kill the germs responsible, the commonest being Amoxicillin. Pain killers (or analgesics) are given to control the pain, panadol is usually sufficient but some people may need stronger pain killers. Lastly, panadol can also do the job in lowering the high temperature as well. The course of the disease is usually between 7 to 14 days.