It occurs as a result of nasal obstruction left untreated or inadequately treated, most often caused by colds or allergies. It happens usually in small children because of the small size of the eustachian tube, a 'tube' connecting the middle ear and the back of the nose. These usually present with fairly sudden onset of earache, not uncommonly at night, several days after the onset of a 'cold'. Hearing is often impaired because the presence of pus in the middle ear impedes sound transmission through the middle ear to the inner ear. Left untreated, the ear drum may rupture, resulting in pus or bloody discharge from the ear.
Treatment involves the use of a combination of decongestants and antibiotics.
Elevation of the head of the bed may be useful. Decongestant nose drops may be helpful in certain situations, but its use must be limited to no more than 3-4 days. Pain-relieving ear drops may be used if there is no rupture of the ear drum. Such fluid accumulation is especially likely if treatment is inadequate. It can also be associated with nasal allergies, adenoid enlargements, and other causes of eustachian tube obstruction.