The Middle Ear and Allergies
The middle ear is an important part of the auditory system. It is a cavity inside the head found between the external auditory canal and the inner ear. In the cavern there are three very small bones, called ossicles which move and transmit sound waves by their movements into the fluid of the inner ear canals. The middle ear is an air filled cavity that house ossicles. They are three very small bones connected to each other in series. The first one, the hammer, is in contact with the eardrum and the last one the stirrup fits into a window leading to the inner ear canal. The middle ear cavity also has a long tube that connects it to the area in the back of the throat, called the Eustachian tube. The function of this tube is to equalized pressure and to provide and outlet for ear secretions.
If the middle ear cavity is supposed to be air-filled, then how does fluid get in it? The cavity is lined with tissue that can be irritated by viruses, bacteria and allergens. Once the tissue is irritated there are chemical reactions that can cause the tissue the weep, like when the nose runs. Under normal conditions the secretions run down the Eustachian tube into the throat and are swallowed. Sometimes the tissue of the Eustachian tubes becomes inflammed due to irritants, they swell and prevent the flow of secretions out of the middle ear. This happens in young children who suffer repeated ear infections. Eventually, there is enough fluid build up in the ear that tubes must be placed in the eardrum to allow the middle ear secretions to drain through the external ear canal instead of the eustachian tube. Once the ear infection cycle is stopped, the tissue inflammation goes down and the eustachian tube relaxes allowing normal drainage.
The middle ear membranes and the Eustachian tube can also respond to allergens. Allergens are contact irritants, they don't cause a disease or illness, they cause a tissue reaction, the tissue swells and weeps. Again, this is a chemical reaction, but it can be impaired by taking antihistamines, Benadryl, Allegra, Claratin, Zyrtex, just to name a few. With the weeping tissue also comes congestion and that is what blocks the Eustachian tubes as well as causing that feeling of pressure and the feeling that the ears need to "pop". This can be helped by decongestants, the most common being pseudoephedrine.
Ideally allergy medicine and decongestants should help, but sometimes in extreme cases they don't. If you have fluid in your middle ear that is not being drained out through the Eustachian tubes, most likely you won't be able to hear well and you are probably feeling a lot of pressure in your ears. If this is the case you should run, not walk, to an Ear, Nose , and Throat specialist or at the very least your Primary Care Doctor who should be wise enough to refer you to a specialist. If drainage of fluid from the middle ears is blocked for a long period of time, permanent hearing loss can result. Who knows you may even have an infection of the middle ear that needs to be treated with antibiotics. If you are sure that the fluid build up in the middle ears was caused by allergy irritants then finding a good program to decrease your sensitivity to those irritants should be pursued.
