Joey’s mom was really worried. Joey had been treated with four antibiotics in the past six months. Now his fever was 101 degrees. Last night, green pus drained out of his ear onto his pillowcase. Joey’s pediatrician had recommended they see an ear specialist, and now Dr. Johnson, the specialist, was suctioning the pus from the ear. He let Joey’s mother look through the ear microscope, and she could see the eardrum had a small hole in it. Dr. Johnson said it would heal itself. When Joey returned a week later, the perforation was indeed gone—but the fluid remained. Dr. Johnson did a hearing test that showed Joey had some hearing loss that would probably be temporary.
Otitis media (OM) is an inflammation of the middle ear. The middle ear is a small space that is normally filled with air (see chapter 1) and is lined by a thin mucous membrane. The middle ear is also connected to the airway system that includes the lungs, trachea, nose and sinuses, Eustachian tube, and middle ear. All of the airway structures contain air and are lined with a continuous mucous membrane from top to bottom. Because of the connections between the parts, infection of one part can spread to another. For example, infections like sinusitis can spread downward to the lungs or upward to the middle ear.
Otitis media is the most common childhood illness, causing some twenty million doctors’ office visits per year. It has been estimated that 90 percent of children have at least one episode of OM before age two and 30 percent of children have at least six episodes by age seven. Otitis media occurs most frequently in babies between six and eighteen months of age, and there is another peak incidence around the time children enter large day care facilities or preschool. Children younger than age six get otitis media much more often than older children. If the first infection occurs in the first year of life, many more usually follow.
Figure 4.1
In otitis media, the middle ear space is filled with fluid that blocks sound waves.
Eustachian Tube Dysfunction
The Eustachian tube (ET) is a narrow connection between the middle ear and the nose and throat. As noted in chapter 1, it is lined with mucous membrane and is normally in the closed position. Specialized muscles open it automatically during swallowing, yawning, or chewing. Or it can be opened consciously by blowing air pressure back into the nose (as we do when we clear our ears for landing in an airplane).
The Eustachian tube is shorter and more nearly horizontal in young children than in adolescents and adults. These two characteristics tend to allow infection or stomach acid to enter the middle ear and cause inflammation of the lining (mucous membrane). The mucous membrane of the Eustachian tube can also become inflamed by inhaled allergens (such as pollen) and by milk that enters the middle ear when a bottle-fed infant drinks while lying on his or her back.
When the Eustachian tube is inflamed, it tends to swell and close more tightly. Mucous from the middle ear may then stop draining and begin to build up, leading to an infection. As a child matures, the Eustachian tube becomes longer and more vertical, and ear infections become less common.
Many other factors play a role in the frequency of otitis media in young children. These include immaturity of the immune system, lack of prior exposure to different strains of viruses and bacteria, inhalation of secondary smoke, and contact with other children who have respiratory infections (runny nose, cough, or sneezing).
Types and Symptoms of Otitis Media
Inflammation of the middle ear takes several forms and can be categorized by the appearance of the eardrum, how long the problem lasts, and complications that may occur. The diagnosis is made by looking through a magnified otoscope or ear microscope while using a pressure bulb. A small puff of air from the pressure bulb will move the eardrum slightly if no infection is present. If fluid is present in the middle ear, the eardrum will not move. The combination of the appearance and movement of the drum are used to make the diagnosis. The most common types of OM are acute otitis media and otitis media with effusion (see below). The other categories can be thought of as progressive stages of complications.
Acute Otitis Media
Acute otitis media (AOM) is usually a bacterial infection that is associated with a rapid onset of pain and temporary hearing loss. The child may also be irritable and have a fever and headache. On examination, the eardrum looks red and often bulging because of the infected fluid buildup behind it. It does not move in response to a slight puff of air. AOM can also be caused by viruses and other less common disorders.
Otitis Media with Effusion
Otitis media with effusion (OME) is a buildup of fluid behind the eardrum without signs of bacterial infection. It may be the result of blockage of the Eustachian tube due to allergy, irritation, or acid reflux. Otitis media with effusion may also be the first or last stage of acute otitis media.
Children with cleft palate or Down syndrome are at higher risk for developing otitis media with effusion because of differences in their anatomy. In addition, children from lower socio-economic families are more likely to have both AOM and OME. This is thought to be correlated with a higher incidence of parental smoking, the use of bottle feeding, and crowded conditions in group day care or the home. Otitis media with effusion is not associated with rapid onset of pain or fever; instead, the symptoms are hearing loss, fullness, and, sometimes, imbalance.
Children who ask for a louder volume on the TV, have difficulty understanding instructions, pull on their ears, or display lethargy or irritability may actually have OME. Sometimes there are no symptoms so it is up to the doctor to order hearing tests and follow-up on anyone who has had acute otitis media to be certain that the fluid resolves after treatment.
Otitis media with effusion may begin with thin watery fluid, but if it persists over time the fluid thickens and turns yellowish. When the fluid reaches a gel-like or even semi-solid consistency, the condition is called chronic otitis with effusion, or sometimes “glue ear.” At this point, the thick fluid is unlikely to resolve even with medications or further waiting.
OME often causes conductive hearing loss by blocking sound waves, and if the condition is not controlled, may lead to multiple recurring episodes of acute otitis media. If allowed to persist for a period of more than three months, OME can lead to language acquisition delays, reading delays, degeneration of the eardrum, and other structural complications. The first few years of life are a crucial time for children to learn language by hearing other people talk. If a young child has even a mild hearing loss, he or she may miss parts of words and that can interfere with language development.
Diagnosis
Medical Examination
The key to the diagnosis is the appearance of the eardrum, but getting a good look at it is often not easy. Infants may have tiny, collapsible outer ear canals, often filled with vernix (the creamy coating from uterine life). Older children may have wax obstructing a full view. Crying in response to being restrained can cause a normal eardrum to turn red (just as the face turns red when a child is crying). Young children and infants generally allow the doctor just a momentary glance before they move. It may become necessary to refer a child to an ear specialist just to get a good look and diagnosis.
Testing
The most useful test for OME is tympanometry (see chapter 26). Tympanometry is used to measure the movement of the eardrum. It is very sensitive to the presence of fluid, stiffness, and position of the drum and middle ear and, in the authors’ experience, it is accurate about 90 percent of the time. This test is done by inserting a probe into the outer ear canal of a child for five seconds or so. If the ear canal is completely blocked, for example by wax, tympanometry will not work. The hearing is also tested to determine the type and degree of loss. Most typical is a mild to moderate conductive loss (see chapter 26).
Treatment
Efforts to prevent OM are safe, effective, and important. The routine vaccination of all children against Streptococcus pneumoniae and Haemophilus influenzae is very helpful, since most episodes of AOM are caused by these two bacteria. Other preventative factors are living in a smoke-free environment, avoiding large day care facilities early in life, nursing for six months, and using a proper nursing position (not flat on the back).
Acute Otitis Media
Unlike throat cultures, which can be easily performed with a swab, cultures of the ear for AOM are more invasive (requiring a needle puncture of the eardrum). Consequently, they are not routinely performed. However, it has been found that 90 percent of AOM can be traced to three bacteria. Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are the most common. Together they cause over 90 percent of AOM. Therefore, antibiotic treatment, when indicated, is tailored to be effective against these three.
However, in newborns and infants less than six weeks of age, more resistant bacteria can also cause AOM and must be accounted for. Some newborns get otitis media before they are discharged from the hospital. That means the bacteria may be resistant to usual treatment. For newborns and infants, the infection is often cultured before treatment.
Viruses play an important role by causing inflammation and mucous membrane damage that allow bacteria to gain a foothold. The most common are respiratory syncytial virus, influenza, rhinovirus, and adenovirus.
Discussions are ongoing concerning withholding antibiotics in routine cases of acute otitis media as well as which antibiotics to use if necessary. As of 2013, a committee of the American Academies of Pediatrics and Family Practice made several recommendations (table 4.1).
Nonetheless, some controversy exists, especially about withholding antibiotics and using the largely ineffective antibiotic amoxicillin. Randomized, prospective, placebo-controlled studies show that antibiotics are highly effective in treatment of AOM and cured study subjects two weeks faster than non-antibiotic treatment.
And although amoxicillin is least expensive, it does not provide the best coverage. Of the three bacteria that cause 90 percent of AOM, H. influenzae is up to 50 percent resistant and M. catarrhalis is 90 percent resistant to amoxicillin.
Use of an antibiotic with such high levels of bacterial resistance can result in unnecessary trips to the doctor’s office and avoidable expense. Resistance varies by community, and individual physicians will know best what works for patients in their community. (The authors of this book favor individualized treatment of all patients rather than one-size-fits-all medical practice.) Ventilation tubes are also used when multiple episodes of AOM occur within a short period of time in spite of multiple courses of antibiotics.
Table 4.1
Recommendations for Physicians Treating Acute Otitis Media (AOM) from the American Academies of Pediatrics and Family Practice
• Avoid using antibiotics in mild cases
• Prescribe amoxicillin as the antibiotic of choice
• Re-evaluate children within seventy-two hours if not treated
• Encourage breastfeeding for the first six months
• Give Pneumococcal and H. influenzae vaccinations
Simplified and summarized from the American Academy of Pediatrics Clinic Practice Guideline, Pediatrics (2013 Mar); 131(3).
Otitis Media with Effusion
About two of every three patients with AOM (active infection) develop OME (residual fluid behind the eardrum). The residual fluid will eventually resolve on its own in most children. As a rough rule of thumb, 30 percent resolve in thirty days, 60 percent resolve in sixty days, and 90 percent in ninety days. If fluid is still present at three months, chances are high that the middle ear effusion will not resolve on its own. While conservative practice, in the authors’ opinion, requires children to wait for three months to see if the fluid will clear up on its own, most adults with the same disorder demand the fluid be removed by one month owing to discomfort and hearing loss. Unfortunately, medical treatments for OME, including antihistamine-decongestants, steroids, and allergy treatment, have no measurable benefit compared to placebo.
Ventilation tubes are often recommended when fluid is present and causes hearing loss in both ears for three months. If OME begins to cause damage by weakening and collapse of the eardrum itself, ventilation tubes may become necessary sooner in order to prevent long-term damage.
Ear Tubes
Ear tubes (also called tympanostomy tubes, pressure equalizing tubes, ventilation tubes, etc.) are small grommets placed through a tiny incision in the eardrum. The tubes are made of a variety of plastics, Teflon, or stainless steel and work by holding the incision open for six to eighteen months before they are extruded by the body. Tubes allow middle ear fluid to escape rather than build up inside the middle ear. Tubes also permit antibiotic drops to enter the infected middle ear space along with air to help the mucous membranes to return to normal. There are several widely accepted indications for placing tubes (table 4.2).
Complications with tubes include perforation of the eardrum, drainage from the ear, obstruction, and early or delayed extrusion of the tubes. With standard tubes, there is a 2 percent chance that the opening in the eardrum may not close on its own. With so-called long-lasting tubes, the residual perforation rate can approach 16 percent. The tube may not extrude on its own and may have to be removed after three or four years of careful observation (2 percent of cases). Some doctors suggest removal by two years, but in our experience, this may lead to the need for re-insertion of tubes a few months later. If drainage through the tube occurs and is not treated with ear drops, the drainage may solidify and form a crust that blocks the tube.
Table 4.2
Indications for Middle Ear Tube Placement
Acute otitis media (AOM)
Three infections in six months
Four infections in twelve months
Otitis media with effusion (OME)
Fluid present for three months in both ears
Fluid present for six months with degeneration in one ear
It was once thought that children with tubes should avoid swimming. However, it is safe for most children to swim without ear plugs or headbands in private, adult pools. Avoid submerging the ear in soapy bath water, hot tubs, and unfiltered or non-chlorinated kiddie pools, freshwater lakes in hot climates, at the beach, and in large public pools. Swimming in the ocean, away from the beach, is permitted because the water is less contaminated and does not contain sand and seaweed particles.
Adenoidectomy
If middle ear infections or effusions return after the first set of ear tubes are extruded it may be wise to replace the tubes in combination with removal of the lymphatic tissue called the adenoids. The adenoids normally act as a trap for bacteria, but after too many infections they may become a reservoir and lead to new infections. Adenoidectomy is a somewhat more risky and painful operation than insertion of ear tubes. There is no reason for someone to have their tonsils removed—to have a tonsillectomy—to treat otitis media, because that surgery does not help prevent or cure ear infections.
Complications of Otitis Media
Chronic Suppurative Otitis Media
Chronic Suppurative Otitis Media (CSOM) is a bacterial infection of the middle ear (AOM) that lasts more than six weeks. To make this diagnosis, some ear specialists also require evidence of drainage of infected material through a perforation of the eardrum. Perforations are caused by infected material under pressure in the middle ear. Most of the time, perforations will close after the pus drains out of the middle ear. But if the perforation persists, you will be referred to an ENT for more comprehensive diagnostic evaluation and treatment.
Adhesive Otitis Media
If fluid remains in the middle ear more than a few months, a series of progressive degenerative changes begin to affect the eardrum. The first change is thinning or atrophy of the eardrum. This is a result of a combination of enzymes in the middle ear fluid and negative middle ear pressure.
Eventually the eardrum collapses (atelectasis of the eardrum). In this case, the middle ear space is mostly gone and the eardrum lies directly on the cochlea and bones of hearing. If it remains there, it will eventually attach to those underlying structures (adhesive otitis), at which time the changes are usually irreversible without major surgery and cause moderate to severe hearing loss.
Spread of Infection
The most frequent complications of otitis media, as noted, are hearing loss, speech, language and reading delay, and degenerative changes of the eardrum. But infectious complications, while less common, are more threatening.
Infectious complications are generally categorized by their location and duration. Infections of the middle ear tend to spread to adjacent air spaces. This can result in mastoiditis (spread to areas behind the middle ear) and petrositis (spread to areas deeper than the middle ear). Infection can also involve the facial nerve and inner ear with very serious results.
Rarely, an ear infection can spread to areas around the brain and may cause meningitis, brain abscess, blood clots in major veins, and hydrocephalus. These intracranial complications can be life threatening.