Barotitis is an inflammation of the ear caused by changes in atmospheric pressure. It is also called aerotitis.
This is a problem of inflammation or bleeding in the middle ear caused by a difference between the air pressure in the middle ear and that of the atmosphere - as occurs in sudden changes of altitude, in diving, and in hyperbaric chambers.
Modern jet aircraft, including the supersonics, maintain cabin pressure equivalent to 5,000 and 8,000 feet. At such altitudes, free air in body cavities tends to expand by about 25 percent and may aggravate certain medical conditions. The occasional loss of cabin pressure and the fact that some airplanes are unpressurized can present problems.
During a sudden increase in ambient pressure, gas must move from the nasopharynx into the middle ear to maintain equal pressure on both sides of the tympanic membrane. If the eustachian tube is not functioning properly, as in upper respiratory tract infections or allergy, the pressure in the middle ear is lower than the ambient pressure. The relative negative pressure in the middle ear results in retraction of the tympanic membrane and a transudate of blood from the vessels in the lamina propria of the mucous membrane forms in the middle ear.
If the difference in pressure becomes great, ecchymosis and subepithelial hematoma may develop in the mucous membrane of the middle ear and in the tympanic membrane.
Very severe pressure differentials cause bleeding into the middle ear and rupture of the tympanic membrane. A perilymph fistula through the oval or round window may occur.
Pressure differentials between the middle ear and ambient pressures usually produce severe pain and a conductive hearing loss.
Upper respiratory inflammation or allergy may obstruct eustachian tubes or sinus ostia, resulting in barotitis media or a sinusitis.
Intense pain in the ear is the hallmark of this problem. Facial pain of dental origin also may occur with air pressure changes.
A sensorineural hearing loss or vertigo during descent suggests the possibility of a perilymph fistula, while the same symptoms during ascent from an aquatic dive suggest bubble formation in the inner ear.
A person with an acute upper respiratory infection or allergic reactions should be advised not to fly or dive. However, if these activities are undertaken, a nasal vasoconstrictor such as phenylephrine 0.25 percent applied topically 30 minutes before descent is of prophylactic value.
Frequent yawning or closed-nose swallowing during descent, decongestant nasal sprays and antihistamines taken before or during flight often prevent or relieve these conditions.
Children are particularly susceptible to barotitis media and should be given oral fluids or feeding during descent to encourage swallowing (chewing gum or hard candy is even more effective than eating).