Expert interview: Talal Nsouli, M.D.TOPIC: Serous Otitis Media and Acute Otitis Media (middle ear infections)

Featuring: Talal Nsouli, M.D.

Expert interview: Talal Nsouli, M.D.

TOPIC: Serous Otitis Media and Acute Otitis Media (middle ear infections)

Dr. Nsouli's Background:

Clinical assistant professor of Pediatrics, Allergy and Immunology at Georgetown University Hospital

Clinical research associate at the International Center for Interdisciplinary Studies of Immunology

Director of the Watergate Allergy and Asthma Center

Medical director of Burke Allergy and Asthma Center Board committee member of the American College of Allergy and Immunology

Board committee member of the American Academy of Allergy and Immunology

Definitions: Serous Otitis Media and Acute Otitis Media

Serous otitis media is also popularly known as otitis media with effusion. These terms are used interchangeably to identify a chronic inflammatory disease of the mucoperiosteal lining of the Eustachian tube, middle ear, and mastoid air cells. With serous otitis media, obstruction of the Eustachian tube occurs that leads to accumulation of fluid in the middle ear. This in turn decreases the compliance or vibration of the eardrum, frequently leading to a conductive hearing loss as well as problems with speech, learning, and behavior.

In contrast, acute otitis media is an infection of the middle ear. Serous otitis media can result from acute otitis media, if not effectively treated, and vice versa. That is, if serous otitis media is not effectively treated and becomes chronic, the fluid that accumulates in the middle ear allows pathogenic bacteria or viruses to replicate, increasing the risk of a mucopurulent fluid buildup, reflecting an acute infection. Clinically acute otitis media is usually characterized by severe, persistent ear pain and fever, while otitis media with effusion is more often associated with much milder symptoms or no symptoms at all.

A culture performed on the fluid of serous otitis media would show bacteria in the middle ear fluid, even without infection. In at least 60 percent of affected children, sample fluid from the middle ear obtained by tympanocentesis will culture pathogenic bacteria.

Up to one-third of acute otitis media patients have evidence of serous otitis media four weeks or later after acute infection has been brought under control. Acute otitis media might lead to serous otitis media and vice versa. The picture is not always clear which condition precedes or causes the other.

In about 75 percent of cases, both ears develop middle ear effusion. In contrast, with acute otitis media, the tendency is for only one ear to become infected.

Statistics on the Costs and Prevalence of Otitis Media

Recurrent or relapse of serous otitis media is considered one of the most challenging problems to the clinician. Serous otitis media is the most common disease in children under 15 years of age, responsible for approximately 25 million office visits each year and afflicting some 10 million children each year in the United States. Also, it's the most common reason for an initial visit to the pediatrician and represents approximately 75 percent of all the follow-up visits. Serous otitis media is the most common disease diagnosed by the otolaryngologist and the most common reason for pediatric surgery in the United States and England.

Serous otitis media is on the increase, with a 150 percent increase overall since 1980, and a 224 percent increase among children under 2 years of age.

Limiting the estimate to medical and surgical intervention along, the annual cost for treatment of otitis media is between $3 to $4 billion each year. However, including the expense of special speech and language therapists, academic enhancement services, learning audiologists, pediatric neurologists, psychologists, and other professional services, the total cost soars to $30 billion per year.

The reason all of these different interventions are needed is very simple. The fluid in the middle ear leads to decreasing eardrum compliance, resulting in conductive hearing loss. This hearing loss might lead to serious alterations in normal language and speech development especially if it occurs at a very early age in the child. Significant hearing loss early in life can have a profound impact on the child in terms of socialization; academic performance; and emotional, mental, and psychological development—all requiring intensive, long-term, and often very expensive treatment.

Risk Factors for Otitis Media

Serous otitis media is more frequent in boys than girls; more frequent in a child if his parent or sibling has also had it; more frequent in Hispanics than in whites, Native Americans, and Eskimos; and more frequent in whites than American blacks.

One study found that if a child experiences an episode of serous otitis media before one year of age and the child's mother has blood type A, the child has up to a 2600 percent increased risk of recurrences.

There are two age peaks with this condition, one from 6 months to 2 years and the other from 5 to 6 years. Then the incidence drops off precipitously from abut 6 to 12 years of age.

One possible explanation for the age peaks might be the problem of food allergies at an early age. Food allergy is a very common problem in childhood, especially during the first 3 to 5 years. After age 5, food allergies seem to decrease significantly.

The reason is because children are bombarded with food beginning at birth. If the child has a personal or family history of atopy, certain foods begin to produce immune responses. It normally takes awhile for the immune system to mature in a very young child in order to start to control the food hypersensitivity. The second phase at about 4 or 5 years of age occurs when the child starts playing outdoors, becoming sensitized to environmental allergens such as the tree, grass, and weed pollens.

Recent upper respiratory infections may precede many episodes of serous otitis media. Some patients will develop otitis media after getting an upper viral respiratory infection, yet other patients will not. A likely explanation for this disparity is that children with atopic diseases have a predisposition to develop certain anti-viral antibodies. Researchers have shown that the most frequently encountered virus in the upper respiratory system in patients with recurring otitis media is the RSV, or respiratory syntitial virus, the same virus frequently associated with asthma and bronchopneumonia in children.

Patients with allergies have a tendency upon acquiring the RSV to develop an anti-RSV IgE antibody that leads to an immune reaction. This reaction includes the RSV virus as the allergen, an anti-RSV IgE antibody, and the mast cell. In other words, children with atopy seem to be prone to develop upper respiratory viral infections in which the virus behaves as an allergen, causing a Type I-like IgE-mast cell degranulation.

Additional important risk factors include the following:

· Seasons of the year appear to represent a risk factor in otitis media, with winter and spring associated with a higher incidence.

· Day care centers and children from large families also seem to be associated with a higher incidence. Day care centers are the best source of pathogenic bacteria, in terms of acquiring upper and lower respiratory infections and exposing the child continuously to infectious agents.

· Passive cigarette smoke and children don't mix either. Children subjected to passive cigarette smoking have a reported 30 to 40 percent increased risk.

· Enlarged, inflamed adenoids appear to increase risk.

· Rhinitis seems to adversely affect the incidence of serous otitis media.

· Many children with autism and attention deficit hyperactivity disorder also seem to have problems with middle ear disease.

Breast feeding appears to offer babies protection from otitis media during the period of breast feeding and for about 12 months after termination. Thereafter, the incidence of otitis media in previously breast fed babies is the same, as if the child had never been exposed to breast milk.

Diagnostic Procedures for Otitis Media

Serous otitis media is a very tricky diagnosis and is often missed, primarily because it's a silent disease. Many of the 10 million children who get chronic middle ear effusion each year get it quietly. Often, the only symptom is loss of hearing. The parent might only notice that the child turns the volume on the TV extremely high. This could be he only observable indicator that it's time to check the child's ears. If clinicians give routine physical exams to the child and only look in the ears with an otoscope, they can very easily miss effusion in the middle ear because the majority of children are uncooperative during an ear exam. They're crying, protesting, twisting, and pushing. in such a situation, even the very best pediatrician would have great difficulty diagnosing middle ear fluid. More sophisticated materials and techniques—such as the pneumatic otoscope—are needed to accurately detect fluid.

The pneumatic otoscope is a simple, but sensitive test. An air bulb introduces a small amount of air into the external ear canal while the physician evaluates the vibration of the eardrum. This technique is called tympanometric testing. Another more accurate method to detect ear effusion is the tympanometric test using a microchannel computer. By using the tympanometer, the clinician can quickly and easily obtain an accurate diagnosis of middle ear fluid.

If the child is less than 6 months of age or is crying during the test, it is not possible to use a tympanometer. Instead, an alternative is to use the sonar analyzer, an acoustic reflectometer, that provides extremely precise ideas about the fluid behind the eardrum.

This much more sophisticated equipment for diagnosing middle ear effusion may explain some of the reported 224 percent increase. Another important message for physicians is that relying solely on a routine otoscopic exam can cause frequent misdiagnoses of otitis media, thereby running a real risk of adversely affecting children later in life.

Of real concern is a 2-year-old who isn't complaining of ear pain, isn't tugging on the ear, isn't feverish, and yet may have chronic fluid in the middle ear that affects the child in a variety of ways, including some irreversible changes in the child's brain. Not only does chronic, recurrent serous otitis media lead to conductive hearing loss, but if left untreated might turn into acute otitis media. Acute otitis media might then spread through the round window that connects the middle ear to the inner ear, causing a purulent labyrinthitis. Because the microorganisms can gain access to the subarachnoid space by means of the cochlear aqueduct, this condition is frequently followed by meningitis, a very serious, life-threatening situation. A simple, uncomplicated case of serous otitis media that's undetected and untreated not only might lead to conductive hearing loss, but also sensory neural hearing loss if an infection spreads to the inner ear.

Therapeutic Approach for Otitis Media

Even a relatively benign middle ear effusion should be treated as a potentially serious medical condition, despite the good chance that the fluid might resolve by itself.

The real concern is not with children who develop one acute otitis media episode a year or one or two episodes of serous otitis media a year, but with the child who is having three, four, five, or six episodes of otitis media each year. These are the children who require a complete, full evaluation; who should be checked by specialists with an interest and expertise in chronic, recurring middle ear disease; and who badly need clinical and laboratory evaluations.

A child developing his or her first episode of acute otitis media, associated with fever and severe, persistent ear pain, should be started immediately on an antibiotic such as amoxicillin in accordance with the recommendations of the 1994 U.S. Public Health Guidelines for the treatment of acute otitis media.

If the child starts with amoxicillin, the usual length of treatment is 10 days. As part of the routine follow-up, in our clinic, we call the parents about three days after the 10-day period of antibiotic therapy has ended. If the child continues to have fever and otalgia, we change antibiotics. The new antibiotic of choice is either macrolide or cephalosporin, depending on the child and the child's hypersensitivities. We routinely see the child 6 to 8 weeks later. If we observe ear fluid at that time, we begin "watchful waiting." Even though the child continues to have fluid in the ears, we advocate a wait-and-see period, choosing not to use any antibiotics.

If the child continues to have middle ear fluid 1½ to 2 months later, we begin to ask detailed questions about atopy in the family and at the same time perform a thorough allergy evaluation. If we don't uncover allergies and the child is not atopic, we continue the watchful waiting. However, if the patient continues to have fluid in the middle ears 2 or 2½ months thereafter, another antibiotic should be tried.

If the child continues to have middle ear problems, we would seriously consider the myringotomy surgical procedure with insertion of tympanostomy tubes in the following circumstances:

· The child has had fluid in the ears for more than four to five months.

· Both ears are involved.

· All therapeutic treatments have been tried, including antibiotics, decongestants, antihistamines, major allergy evaluation, and allergy treatment.

The U.S. Public Health guidelines do not mention the use of systemic corticosteroids, but they can be extremely effective in clearing middle ear effusion and improving the status of the child. Systemic corticosteroids can clear middle ear effusion in a lot of children considered to be candidates for myringotomy with tympanostomy tube insertion, resulting in deferral of surgery. The treatment regimen with systemic corticosteroids is 7 to 10 days. Ten days is the maximum to avoid corticosteroids' well-known side effects.

If the child doesn't clear on corticosteroids, myringotomy with tympanostomy tubes should be performed to prevent irreversible ear disease.

If the child has an underlying food allergy that wasn't diagnosed and treated, after the extrusion of the tympanostomy tubes 3 to 6 months later you would expect a recurrence of middle ear fluid.

The Antibiotics Controversy Regarding Otitis Media

The overuse of antibiotics has become a very controversial subject. Major resistance of pathogenic bacteria to antibiotics is one of the most serious problems in the field of medicine. In response, many doctors withhold antibiotic treatment initially due to the recognition that 60 to 80 percent of otitis media episodes remit spontaneously within the first few months.

A study reported in JAMA that was performed by Dr. Cantekin, Ph.D., from the University of Pittsburgh, concluded that there was a lack of evidence that antibiotics worked better than no antibiotics at all in the prevention of recurring serous otitis media. Further, Cantekin found an up to 600 percent increased risk of recurring serous otitis media with the antibiotics over no antibiotics. The Cantekin study concluded that early antibiotic intervention made the situation worse.

A similar study, appearing in a 1981 issue of Lancet, concluded the same. Von Buchem and colleagues performed a comparative study using antibiotics alone, placebo alone, antibiotics with myringotomy, and myringotomy alone. Their conclusion was that in terms of preventing otitis media, the placebo worked as well as any one or combination of the more traditional therapies.

However, a number of variables may not have been considered in studies like Cantekin's and von Buchem's. For example, some of the patients in the group chosen to be evaluated could have had hidden, undetected food allergy or allergic rhinitis. Other key variables could be the time of year the study was done, where the study was done, and how the study was performed. It's necessary to consider a number of variables before passing judgment about use or overuse of antibiotics in the treatment of otitis media.

The Role of Food Allergies in Otitis Media

The premise underlying antibiotic treatment is that the pathogenesis of the disease is primarily bacterial in origin. But the pathogenesis of serous otitis media is not fundamentally a microbiological or pathogenic bacterial process. Fluid in the middle ear is more an inflammatory process, more specifically a chronic inflammatory disease of the mucoperiosteal lining that causes obstruction, closing off the Eustachian tube, middle ear, and mastoid air cells. This is where food allergy plays a key role. Often a chronic ear inflammation results from a food-allergic response, one that clinicians frequently underestimate and misdiagnose.

If you ask any knowledgeable clinician what he or she thinks causes serous otitis media, or if one carefully reviews the medical literature, the honest answer is that we don't really know how to treat serous otitis media. But we should carefully review what we do know. For example, at least 55 percent of the people afflicted with recurrent serous otitis media have allergies or atopy. In other words, in a normal, controlled population of 100 children suffering from recurring serous otitis media, at least 55 percent of these patients have allergies. This is one important fact that we do know and we should treat what we know—namely allergies—before we say we don't know the cause of serous otitis media.

The purpose of our study ("The role of food allergy in serous otitis media," Annals of Allergy, September 1994) was to show a possible cause-and-effect relationship between food hypersensitivity and recurrent serous otitis media. Initially, we had about 220 patients selected for recurrent serous otitis media. We did not select them for food allergy whatsoever. After a careful selection process, we were left with 104 patients with recurrent otitis media.

Of the 104 patients, 81 of them suffered from IgE-mediated, Type I food allergies as identified by the skin prick test and the food-specific IgE ELISA blood test. We focused on 10 of the most common food allergens, including cow's milk, eggs, wheat, corn, soybean, and peanuts. After identifying the 81 food-allergic patients and the foods to which they were individually allergic, we then put these 81 patients on exclusion diets for approximately 16 weeks, monitoring the middle ear fluid of each patient about every 2 weeks in our office.

We observed that 70 out of the 81 patients, or 86 percent, cleared their effusion. Seven of the 81 patients quit the diet because they didn't want to stop eating the suspected allergic foods, and only four patients failed to improve at all by avoiding foods. We then asked the responsive patients to eat the food allergens. That is, we challenged them with the specific offending food allergens for 16 weeks, again seeing them every 2 to 3 weeks in our office.

We used not only our eyes but objective testing as well. Using the tympanometer and sonar analyzer, we recorded objective data over a period of 12 to 16 weeks. We found that 66 of the 70 food-allergic patients (94 percent) relapsed with recurrence of middle ear fluid while eating allergic foods. Two patients dropped out of the study, so only two patients out of the 70 who completed the study did not have a reactivation. At least 94 percent of them had a reactivation of serous otitis media, with P value less than 0.001.

Our clinic is known to deal with food allergies, with referrals for food allergy workups from pediatricians, otolaryngologists, and others. Therefore, we might have inadvertently allowed a certain bias into the study. This might explain the unexpected 78 percent incidence of otitis patients with food hypersensitivity.

Nevertheless, our findings are still extremely significant. We were able to help a lot of these patients who were considered hopeless. The parents had given up hope of ever controlling their child's middle ear disease. Before being referred to our clinics, most of these children had already had major complications, including significant hearing loss and learning disabilities in school. The parents had incurred major expenses resulting from these complications. Thanks to the food allergy evaluation and the resulting avoidance of allergic foods, we were able to control and reverse major middle ear problems. The children began hearing well again and returned to school with normal hearing.

Our article's concluding recommendation is this: The possibility of a food allergy should be considered in all patients with recurrent serous otitis media and a diligent search for the putative food allergen made for proper diagnostic and therapeutic management.

The important concept to emphasize here is recurring middle ear problems. We are not talking about the child who has one or two episodes of otitis media a year, but of children who have multiple recurrences.

Atopy exists in at least 55 to 60 percent of children with recurring middle ear fluid. It's important to take a close look at the allergy side of otitis media by performing a thorough allergy evaluation and treatment protocol. If our experiences with food allergy and serous otitis media are of any value, physicians following our recommendations should begin to see significant improvement in many of these severe cases.