Ear disease causes significant discomfort and hearing loss. It also creates work loss and decreased productivity-- this increases as the persons communicative skills decrease when associated hearing loss increases. In children, developmental delays and academic failure may result. Complications such as deafness, meningitis, brain abscesses, and facial nerve paralysis may also occur. Proper management of ear disease is critica.
The basic underlying problem causing most forms of otitis is eustacian tube dysfunction. Most otitis occurs in patients whose eustacian tube, the tube between the nose and the middle ear (the area behind the eardrum), does not work properly. When air cannot adequately get through this tube to the middle ear,the negative pressure created can "suck" fluid out of the lining of the middle ear/mastoid, filling the middle ear and mastoid air cells with fluid. A mild hearing loss usually accompanies the fluid. The hearing loss disappears when the fluid is gone as long as there are no other causes for the hearing loss. Three kinds of otitis can result from eustacian tube dysfunction. They are serous and secretory otitis, where fluid fills the middle ear and mastoid, acute otitis, where pus fills the middle ear and mastoid but its presence is of short duration, and chronic otitis, where pus fills the middle ear and mastoid and it has been present for months or years. Chronic otitis is associated with infection of the bone itself and thickening and polyp formation of the mucosal lining of the middle ear and mastoid. The highest incidence of otitis media occurs in preschool children and decreases gradually after age 6. The highest incidence occurs poor children, children in day care, and Native Americans. Additional factors that cause or aggravate otitis include the presence of enlarged adenoid tissue, lack of proper muscle in the back of the throat (as in those with a cleft palate), allergy, immune deficiencies, sudden change in atmospheric pressure (like poor pressurization in an airplane dropping from a high altitude), scarring or tumors in the nasopharynx, and abnormal cell function of the mucosa of the ear and nose. Diabetes does not increase the incidence of otitis, but can make it much more difficult to treat.
Serous otitis, where fairly clear fluid fills the middle ear and mastoid, occurs with fairly sudden obstruction of the eustacian tube. A sudden descent of an airplane with poor pressurization or a bad cold are two of the most common causes of acute serous otitis media. Usually decongestants will clear the fluid or even blood that can be sucked from the mucosa into the middle ear with wither of these processes. If the fluid does not clear within a few weeks, it is considered chronic serous otitis. Older people with poorly functioning eustacian tubes commonly have recurrent serous otitis and may require intermittent tube placement over many years. Hearing loss is present depending on the amount of fluid in the ear. The hearing loss usually resolves when the fluid is cleared out of the ear, either medically or surgically.
Secretory otitis, where somewhat thicker fluid fills the middle ear and mastoid, is common in small children and is often "outgrown" by the time they reach their teens. It is the most common disease process requiring the placement of PE tubes. This thicker fluid has components that are actually "secreted" by the mucous glands of the middle ear. There are actually tissue breakdown enzymes in this fluid; that, if left untreated, can gradually eat away bone and cause chronic hearing loss/damage. Luckily, it generally takes quite a while for these enzymes to cause damage to the ear, so treating secretory otitis in children with medication for a few weeks or months is safe. Leaving this kind of fluid in an ear for more than several months, however, places the ear tissues (including the tiny ear bones) at risk of damage or destruction by these enzymes. Not treating infections with antibiotics at all places the ear structure at even higher risk of permanent damage/destruction by the fluid.
Acute otitis media occurs when pus fills the middle ear. It is usually sudden in onset and is often associated with sudden obstruction of the eustacian tube at the same time infections bacteria are present to cause the acute otitis. Without antibiotic treatment, a true bacterial acute otitis is often associated with sudden perforation of the eardrum, with profuse drainage from the ear. Often the eardrum will spontaneously heal over after the infection has resolved, but a perforation can be left and damage to the middle ear and/or the inner ear can accompany the infection. The eardrum may be bright red or the creamy color of the fluid can sometimes be seen through the eardrum. It sometimes looks "soggy." Pain and fever may accompany an ear infection, but usually disappear rapidly if the eardrum perforates. Pain and fever are rarely present if there is a hole (perforation) in the eardrum before the infection starts. The standard treatment of acute otitis media is oral antibiotics. Ear drops are added if the eardrum perforates. IV antibiotics are indicated for severe infections, if the mastoid bone is also infected, or if the facial nerve becomes paralyzed as a "complication" of the acute infections. Hearing loss is present but usually goes away when the infection clears.
Chronic otitis media occurs when chronic infection fills the middle ear space and mastoid cavity. True chronic otitis media is almost always a form of chronic mastoiditis, where the bone of the mastoid cavity (the honeycombed bone behind the ear) is chronically infected along with the tissues of the middle ear space. It is important to realize that antibiotics alone usually cannot remove infection from the bone; surgical removal of the infected bone is usually necessary to accomplish this. Even IV antibiotics do not often eradicate a true bone infection, especially in the mastoid, which has its connection to the bacteria-filled nose through the eustacian tube. A cholesteatoma is a common additional finding along with chronic otitis and mastoiditis. A cholesteatoma is a skin sac that grows back into the middle ear or mastoid from the eardrum, creating a mass of skin and debris that keeps getting larger and larger over time, destroying anything in its path. The ear bones, the inner ear, the facial nerve (the nerve that makes all the muscles of one side of your face work), and the brain next to the ear can all be damaged or destroyed by either spreading infection or cholesteatoma. These diseases must be removed fore the safety of the ear, the head, and the brain. Infection or cholesteatoma involving the inner ear, facial nerve, or the brain requires immediate attention by an ear surgeon and often required immediate surgery.
Hearing loss usually accompanies chronic otitis and cholesteatoma. There is usually a considerable conductive hearing loss and there may be sensorineural hearing loss as well. The longer the ear is infected, the more likely it is that toxins from the infection seep into the inner ear, causing sensorineural hearing loss. Sensorineural hearing loss resulting from infection is generally permanent and can rarely be reversed. Repair of the conductive hearing loss should only be attempted after the infection and/or cholesteatoma is controlled. Sometimes ear surgery has to be done in "stages" because of this fact.
Cholesteatoma is skin cells that grow in the wrong places in the middle ear and mastoid. Less commonly, it can invade the inner ear, brain, or any other structure of the ear area/brain. As the skin mass expands, it can destroy anything in its path. Infection often accompanies a cholesteatoma. The ossicles (ear bones) are often destroyed by even the smallest cholesteatoma. These masses are not cancerous but must be removed to prevent the ear from being severely damaged.
Otosclerosis is a kind of ear disease in which the otic capsule, the hard and "different" bone that is present only around the inner ear, is replaced in patches by soft bone at random locations around the inner ear. When this soft bone starts growing at the edge of the stapes footplate, the stapes bone cannot move like it should and sound is not passed properly from the middle ear to the inner ear, creating a conductive hearing loss. This is often repairable. When otosclerotic bone replaces bone in other parts of the otic capsule, a sensorineural hearing loss can result. The nerve hearing loss cannot be repaired surgically.
Menière's disease is caused by an imbalance in the fluid in the sacs in the inner ear. When the sacs of the endolymphatic system of the inner balloon within the inner ear, a sudden hearing loss, vertigo, ringing (tinnitus), and/or pressure in the ear occur. This disease is episodic (by definition) and erratic in its progression. If left to its natural course, it may progress to total deafness in the affected ear. At that point, the episodes of vertigo and the tinnitus may spontaneously subside.
An acoustic neuroma is a benign tumor of the balance nerve between the inner ear and the brain. It grows very slowly. It can cause vertigo (dizziness), hearing loss, and loss of function of the facial nerve. It causes its damage by local enlargement with destruction of the structures it presses against. It is especially noted for creating a loss in understanding ability (discrimination) of the ear that is significantly worse than the actual hearing loss. When hearing loss is not equal between the two ears (unless there is a known reason for this), an acoustic neuroma should be suspected. An MRI scan enhanced with gadolinium is the test most often used to diagnose an acoustic neuroma. If diagnosed when tiny, it may be observed or removed surgically depending on its size at the time of diagnosis and the age of the patient. Larger tumors should generally be removed surgically. This is generally done by a neurotologist with or without the assistance of a neurosurgeon.
The following topics are nicely discussed in excerpts from the website of the American Academy of Otolaryngology, Head and Neck Surgery. Please click on any of the topics to connect:
How the Ear Works