Serous otitis media is an accumulation of fluid in the middle ear, which occurs either from incomplete resolution of acute otitis media or from the obstruction of the eustachian tube from noninfectious causes. It is most commonly observed among children, and symptoms include hearing loss and a sense of fullness and pressure in the ear. Diagnosis is made through physical examination, and treatment is indicated only if the symptoms persists for months.
The clinical presentation of serous otitis media can be asymptomatic, and about 40-50% of documented cases report no symptoms. However, the most common clinical presentation of patients is hearing loss, and sometimes parents of children are the first to notice these changes. In addition to hearing loss, a sense of fullness and pressure is also reported by patients. Further, a popping sensation in the ear when swallowing is also observed.
Patient history is vital in the setting of serous otitis media, as most cases occur after an acute infection of the middle ear. In all patients who had a prior middle ear infection, the suspicion toward serous otitis media must be made, especially if symptoms last for a prolonged period of time.
The otoscopic examination is performed to evaluate the status of the tympanic membrane and the surrounding structures. During otoscopy, a grayish color of the tympanic membrane may be observed, displacement of the light reflex, and a certain degree of retraction. If a pneumatic otoscope is used, the tympanic membrane may be immobile.
Workup comprises a targeted physical examination, including an otoscopic examination of the ears, in order to determine the cause of hearing loss. Tympanometry may be performed to confirm the presence of fluid in the middle ear, and thus establishing the diagnosis of serous otitis media [9].
In addition to ear examination, the workup should include a full examination of the nasal cavity and pharynx, to exclude other causes that may be responsible for obstruction of the eustachian tube, such as hypertrophied adenoids, or malignant and benign tumors.
Serous otitis media resolves on its own in a period of two to three weeks, and no therapy is usually required. However, if the condition gains a chronic course, treatment is necessary and is primarily targeted to the underlying cause.
The middle ear can be temporarily ventilated with the Valsalva maneuver. The maneuver is performed by keeping the mouth fully closed and both nostrils pinched. The patient tries to blow the air forcibly through the nostrils, which will result in an air trying to reach the middle ear through the eustachian tube, and "ear popping" will occur as a result, leading to a temporary relief. Another maneuver is called politzerization, which requires the presence of a physician and includes blowing air with a middle ear inflator into one of the patient's nostrils while keeping the other nostril tightly closed. While the patient swallows, the air is forced into the eustachian tube and the middle ear. However, neither of these procedures should be performed if the patient is suffering from rhinorrhea or other respiratory infections.
If no improvement occurs after one to three months, myringotomy may be performed [10]. Myringotomy comprises incision of the tympanic membrane, in order to relieve the pressure in the middle ear and drain the existing fluid, which can sometimes be performed by insertion of tympanostomy tubes [11], which aid in the process of drainage. Tympanostomy tubes may be also inserted for patients with a persistent conductive hearing loss, but also to prevent recurrent acute otitis media, which may cause further complications.
Patients who are suffering from allergies need to receive proper therapy including antihistamines and topical corticosteroids, which may be helpful in alleviating symptoms. Patients with hypertrophied adenoids and those with discovered tumors should be treated surgically. Antibiotics and decongestants are not effective therapeutic strategies [12], hence antibiotic therapy is given only if there is an evidence of additional bacterial rhinitis, sinusitis, or nasopharyngitis.
Serous otitis media generally has a good prognosis, and most episodes spontaneously resolve without treatment and need for intervention. However, this condition often goes undiagnosed, and chronic serous otitis media may cause permanent hearing loss. Moreover, it is considered to be the leading cause of a hearing loss in young children. In some children, even appropriate surgical therapeutic measures may not prevent the recurrence of serous otitis media, and it is estimated that about 20-50% of children will have a recurrence after spontaneous ventilation tube extrusion, which then requires placement of such tubes for years. Additionally, it is associated with delayed language development in children younger than 10 years. All of these factors implicate the potentially debilitating consequences of this condition and signify the importance of prompt diagnosis and proper therapy when necessary.
Serous otitis media may occur as a result of several conditions, the most common being an incomplete resolution of bacterial otitis media (most commonly caused by Streptococcus pneumoniae), which makes the middle ear susceptible to fluid accumulation and improper drainage. Secondary inflammatory processes in the nasopharynx, such as rhinitis, sinusitis, and pharyngitis may also be responsible for the development of this condition, through mechanical obstruction of the eustachian tube. Non-infectious causes, such as the presence of hypertrophic adenoids, lymphoid aggregations, but also malignant and benign tumors may be the causes as well, through the same mechanism. Allergic conditions, such as hay fever, in which swelling of mucous membranes could occur, may also cause obstruction of the eustachian tube. Congenital conditions, such as cleft palate [3], have also been implicated as causes of serous otitis media [4].
Serous otitis media is most commonly diagnosed in children [5], and it was estimated that about 90% of children had at least one episode of serous otitis media by four yeas of age [6]. Additionally, the prevalence rate of serous otitis media decreases with age, being about 3-4% in children between six to eight years. However, this condition may be observed in any individual, regardless of age and gender.
Under physiological conditions, the eustachian tube serves as a ventilation mechanism, thus establishing the pressure equilibrium, and is the primary route for removal of secretions. The eustachian tube is still immature and underdeveloped in young children, which is why this condition is much more commonly observed among them [7].
When the functions of the eustachian tube are disrupted, as in the presence of acute otitis media, or mechanical obstruction from any causes, negative pressure inside the middle ear is created as a result of mucosal absorption of oxygen and other substances, which leads to the formation of a transudate fluid within the middle ear. This fluid (which is called serous because of its composition) accumulates in the middle ear, leading to obstruction of the hearing apparatus, thus causing symptoms of impaired hearing. If this fluid is not drained, or removed from the middle ear, it may cause permanent hearing loss. Initially, this fluid is sterile, but it is a favorable medium for bacterial growth.
It is mentioned that serous otitis media most commonly occurs after acute otitis media. In the setting of acute otitis media, the bacterial infection of the middle ear causes disruption of a regular function of the middle ear and creates favorable conditions for the development of serous otitis media. Newer theories suggest that some other factors are involved in the pathogenesis of serous otitis media, such as extraesophageal reflux, which brings into question other mechanisms that are involved in the development of this condition [8].
Factors which may aid in the prevention of serous otitis media:
Prevention of consequences of serous otitis media can be achieved primarily through a timely diagnosis since the majority of cases reach chronic stage due to missed diagnosis.
Serous (or secretory) otitis media occurs due to insufficient drainage of fluid inside the middle ear, leading to fluid accumulation [1]. It most commonly occurs after acute otitis media (most commonly caused by bacterial infection), or due to obstruction of the eustachian tube from noninfectious causes [2]. It is one of the leading causes of deafness in children and is primarily encountered among young children. The course of illness may be asymptomatic, but symptoms are often present, including hearing loss, and a feeling of pressure and fullness in the affected ear. It is not uncommon that family members recognize a hearing loss of the patient first. The diagnosis of serous otitis media is made clinically and by performing otoscopy. Also, tympanometry may be performed to confirm the presence of the fluid in the middle ear. The clinical examination must comprise nasopharyngeal inspection, to exclude malignant or benign tumors as causes of eustachian tube obstruction. Treatment comprises supportive therapy in most cases, while myringotomy with tympanostomy may be indicated if the disease does not spontaneously regress within a few months. Underlying nasopharyngeal conditions which may cause this condition to be chronic should be managed, such as adenoidectomy, while antibiotic therapy is given only if the development of bacterial rhinitis, sinusitis and nasopharyngitis occur. Prognosis is good, the majority of cases resolve either with or without treatment, but about 5% of children who do not receive proper treatment for chronic serous otitis media experience permanent hearing loss.
Serous (or secretory) otitis media implies the presence of fluid in the middle ear, in which the key components of the hearing apparatus are located. This condition most commonly occurs after an acute infection of the middle ear (most commonly due to bacteria), or due to other causes that cause obstruction of the eustachian tube, which is responsible for normal ventilation of the middle ear. When the eustachian tube is obstructed, the negative pressure inside the middle ear causes the surrounding cells to create small amounts of fluid, which accumulate over time and cause hearing difficulties and may even cause hearing loss.
Apart from preceding otitis media, other causes include enlarged adenoids (lymphoid tissue in the throat), allergies, but also malignant and benign tumors that mechanically obstruct the eustachian tube.
Serous otitis media most commonly occurs in young children, which can be partly explained by the fact that the eustachian tube is not completely formed until three years of age, making children particularly prone to this condition.
The most common clinical presentation is hearing loss, which is often noticed by family members, while a sense of pressure or fullness is also commonly reported. This condition may be asymptomatic as well. A definite diagnosis is achieved through a detailed examination of the ear with an otoscope, with which the physician evaluates the status of the eardrum, and can indirectly assess the status of the middle ear. Other procedures may aid in the diagnosis, such as tympanometry.
Serous otitis media can spontaneously resolve without any therapy. However, if the condition becomes chronic, and remains untreated, it may lead to permanent hearing loss, and this condition is the most common cause of hearing loss among children, which is why this condition must be diagnosed promptly and treated properly.
The fluid that is chronically accumulated inside the middle ear needs to be drained, and it is performed through a procedure called myringotomy, which implies incision of the eardrum, and sometimes a placement of a tube that aids in draining the fluid from the middle ear. These tubes may often stay there for months, or sometimes even years, if necessary. Antibiotics and decongestants are not effective for treatment of this condition, and bacterial infection is not responsible for the accumulation of fluid, which is why antibiotics will not help.
Treatment strategies also include the elimination of the underlying cause, such as surgical removal of enlarged adenoids, or managing allergies with proper drugs.