Middle ear infections, also called acute otitis media, is the most frequent reason for a sick child to visit their doctor’s offices in the United States. In 2000, it was estimated that annual costs for the diagnosis of middle ear infections totaled approximately $5 billion in the United States; 40 percent of these costs were for care of children between the ages of one and three years. 30 percent of all antibiotic prescriptions for children were for middle ear infections. Placement of ear tubes, also called tympanostomy tubes, is second only to circumcision as the most frequent surgical procedure in infants. The procedure is performed for children with persistent middle ear fluid or severe and/or recurrent middle ear infections.
Between 60 and 80 percent of infants have at least one episode of middle ear infection by one year of age, and 80 to 90 percent by two to three years. The most common age for a middle ear infection occurs between 6 and 24 months of age in the United States. Subsequently, the occurrence declines with age except for an uptrend in cases between five and six years of age, the time of school entry. Middle ear infections are uncommon in school-age children, adolescents, and adults, but the bacteria responsible for the infection and the antibiotics used to treat it are similar to those in infants and children. It is slightly more common in boys than girls.
Middle ear infections occur most commonly from 6 to 18 months of age. Children who have had little or no ear infections by the age of three years are unlikely to have a severe or recurrent infection. The occurrence of infection early in life is probably a result of a number of factors:
The spread of bacterial and virus is common in day care centers. There is more opportunity for spread of respiratory infections among children in daycare. Children attending day care centers, especially with four or more other children, have been shown to have a higher chance of getting middle infections than those who receive care at home.
Breast feeding, for at least three months, decreases the amount of normal bacteria that lives within the nose which, as a result, causes fewer episodes of middle ear infections. The reasons for this decrease in middle ear infections remains unclear but it may be because of the protective antibodies in breast milk, the increased facial musculature a baby develops with breast feeding, or the position a baby is maintained in during feeding from the breast in contrast to bottle feeding.
Tobacco smoke and air pollution
Exposure to tobacco smoke and air pollution increases the risk of middle ear infections.
Social and economic conditions, sleep position, season (there is an increase in infections during the fall and winter months), having a weak immune system, or medical conditions such as cleft palate, Down syndrome, and seasonal allergies.
How It Develops
A child will usually have an upper respiratory tract viral infection or allergy which then results in congestion buildup within the nose, the back of the mouth and the eustachian tube. Congestion of the eustachian tube blocks the narrowest portion of the tube which then acts as a suction causing fluid to be drawn into the middle ear. The fluid then has no way to drain so it accumulates in the middle ear space. Viruses and bacteria that live within the upper respiratory tract can reach the middle ear and repeated growth results in an accumulation of pus along with symptoms of a middle ear infection. The middle ear fluid may persist for weeks to months after antibiotics have cleared the infection.
It is common for middle ear fluid to remain after an ear infection goes away. Persistent middle ear fluid is associated with hearing loss. Persistent middle ear fluid may lead to the mistaken diagnosis of middle ear infection in patients with illnesses resulting from other unrelated causes.
Cause of Infections
The causes of middle ear infections have been documented by cultures of middle ear fluid obtained by testing of middle ear fluid. Respiratory tract bacteria and/or viruses can be detected from the vast majority of middle ear fluid from children with middle ear infections.
Bacteria — three types of bacteria account for most of the infections of middle ear fluid: Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. This continues to be true even after the introduction of the Hib and Pneumococcal vaccine to the routine childhood immunization schedule.
Viruses — viral infections are frequently associated with middle ear infections. The most frequently isolated viruses were respiratory syncytial virus, rhinoviruses, influenza viruses, and adenoviruses.
Symptoms of Middle Ear Infections
Middle ear infections are most common in infants and children, although it may occur at any age. Symptoms include ear pain, feeling of pressure sensation, decreased hearing, dizziness, and fever. Older children and adolescents are more likely to complain of ear pain than children younger than two years. Ear pain is less likely to be noticed in patients younger than age two.
Ear-related symptoms, including earache, rubbing of the ear, and the feeling of a blocked ear significantly increased the probability of a middle ear infection, although 32 percent of children younger than two years will have no ear-related symptoms.
On exam your doctor will typically look for redness of the eardrum and decreased mobility of the eardrum. Occasionally small bubbles will be seen on the eardrum.
Rarely, when the middle ear fluid collection is severe, the eardrum will bulge outward. When this happens, the rupture of the eardrum is imminent. After the eardrum ruptures a child’s pain will typically improve, and the child will later notice ear drainage. The eardrum should heal on its own in most cases. When the perforation persists, it may develop into a chronic ear infection.
When pain and swelling is located in the back of the ear (this is called the mastoid region) along with an ear infection, it may be a result of an accumulation of pus within the mastoid cells. This alone does not indicate the need for surgical intervention. Obvious swelling over the mastoid region or abnormalities in the nerves of the face indicates severe disease requiring urgent medical care. Other symptoms include fever, irritability, headache, lack of interest in activities, loss of appetite, vomiting, and diarrhea.
Otitis-conjunctivitis — Ear and eye infections may be seen together. This is usually caused by is H. influenzae.
Bullous myringitis — this is an inflammation of the ear drum that occurs independent of ear infections where small bubbles are present on the eardrum. Bullous myringitis occurs in approximately 5 percent of cases of middle ear infections in children younger than two years. Both viruses and bacteria cause bullous myringitis similar to that in cases of middle ear infections without bubbles. However, children with bullous myringitis usually have more pain at the time of diagnosis. The treatment and prognosis for bullous myringitis are the same as for middle ear infections without bubbles.
Hearing Loss- Persistent or hearing loss that comes and goes is present in most patients with persistent middle ear fluid. The hearing loss continues as long as fluid fills the middle ear space. The average loss is 25 dB, which is equivalent to putting plugs in the child's ears. Some studies have noted that children chronic middle ear fluid have lower scores on tests of speech, language, and learning abilities. In addition to hearing impairment, patients with ear infections may suffer inner ear, balance, and coordination problems.
Eardrum perforation —a perforated eardrum may occur in cases of middle ear infections because the pressure of the middle ear fluid on the ear drum membrane can lead to perforation and drainage.
Mastoid inflammation — Because the mastoid air cells are connected to the far end of the middle ear through a small canal, most episodes of middle ear infections are associated with some inflammation of the mastoid. In rare cases, the mastoid infection does not go away, and acute mastoiditis develops with pus filling the air cells.
Others —other serious infections involving the bones of the skull can occur by spread of infection.
Although uncommon in US, other complications remain a concern where access to medical care is limited. These complications include meningitis, abscess within the tissues that cover the brain, brain abscess, clotting of the arteries and veins that supply the brain.
Expert guidelines suggests that managing a middle infection without the use of antibiotics is an option for some children with simple middle infections based on the level of confidence in the diagnosis, age, illness severity, and assurance of follow-up. Studies have shown that most children with middle ear infections do well, even without antibiotic treatment. All children younger than six months and all children with "severe" illness (moderate to severe ear pain or fever =39ºC in the last 24 hours) should be treated immediately. The option to not use antibiotics is reserved for children older than six months with non-severe illness. Studies have shown that some children older than six months with middle ear infections can be safely treated initially without antibiotics. Symptoms go away more rapidly in children who are treated with antibiotics, but the effect of decreased antibiotic use on antibiotic resistance may outweigh the benefit of shortening the course of the infection.
Antibiotic therapy should be administered to any child younger than the age of six months, regardless of the degree of diagnostic certainty. For children ages six months to two years, antibiotic therapy is recommended when the diagnosis of middle ear infection is certain or if the diagnosis is uncertain but illness is severe (moderate to severe ear pain or fever =39ºC in the previous 24 hours). Not using an antibiotic is an option for children in whom the diagnosis is not certain and illness is not severe. For children older than two years, antibiotic therapy is recommended if the diagnosis is certain and illness is severe. Not using antibiotics is an option when the diagnosis is certain but illness is not severe, and in patients with an uncertain diagnosis. Not using antibiotics is appropriate only when follow-up can be ensured and antibiotic therapy can be started if symptoms persist or worsen. Adequate follow-up may include a follow-up visit or phone call to their doctor to see if symptoms have worsened or have not improved at 48 to 72 hours. Antibiotics should be prescribed when a child does not improve without antibiotics after 48 to 72 hours.
Many different types of antibiotics are commonly used to treat middle ear infections. Two antibiotic ear drops (eg, ofloxacin and ciprofloxacin-dexamethasone otic) are also used to treat middle ear infections with pus drainage in children with ear tubes or eardrum perforation.
The treatment of acute middle ear infection is antibiotic therapy. Symptoms of middle ear infections usually go away in 24 to 72 hours with appropriate antibiotic therapy, and somewhat more slowly in children who are not treated. Amoxicillin remains the drug of choice because it is effective, safe, relatively inexpensive Experts recommend a dose of amoxicillin of 80 to 90 mg/kg per day. For heavier children, a maximum dose of 3 g/day can be used, although diarrhea is a potential side effect at higher doses. Only S. pneumoniae that are highly resistant to penicillin will not respond to this treatment. As a result, more than 80 percent of children with pneumococcal middle ear infections will respond to high-dose amoxicillin treatment.
Erythromycin (50mg/kg/day) plus sulfonamide (150mg/kg/day) can also be used. Alternatives useful in resistant cases are cefaclor (20-40mg/kg/day) or Augmentin (20-40mg/kg/day).
Amoxicillin should not be used as first-line therapy in children who are at high risk for resistant organisms; these include:
-Children who were treated with antibiotics in the previous 30 days, especially penicillin antibiotics.
-Children with eye infections that have pus discharge (otitis-conjunctivitis syndrome usually caused by H. influenzae). This infection is usually resistance to Amoxicillin.
-Children receiving amoxicillin for prevention of recurrent middle ear infections (or urinary tract infection).
Children in the above categories should be started on an antibiotic such as Augmentin.
Penicillin allergy — Acceptable alternatives to penicillin in patients with allergy to penicillin depend upon the type of the previous allergic reaction. In patients that have a penicillin allergy but who did not experience hives or severe allergic reaction the following alternative antibiotics can be used:
- Cefdinir (14 mg/kg per day in 1 or 2 doses; maximum dose 600 mg/day)
- Cefpodoxime (10 mg/kg per day once daily; maximum dose 800 mg/day)
- Cefuroxime (cefuroxime axetil suspension: 30 mg/kg per day in two divided doses, maximum dose 1 g/day; cefuroxime tablets: 250 mg every 12 hours)
It should be noted that these antibiotics are not effective enough to eradicate penicillin-resistant S. pneumoniae.
A single injection of ceftriaxone (50 mg/kg) will last for more than 48 hours and may be considered an alternative for children with middle ear infections and history of a penicillin allergy causing a rash. If symptoms improve within 48 hours following administration of ceftriaxone, no further therapy is necessary. If symptoms persist, a second dose is administered and, if necessary, a third dose.
Antibiotics called Macrolides may be used in children with serious reactions to penicillin. However, macrolide resistance is common (approximately 35 percent) with S. pneumoniae, and macrolides generally are not effective for eradication of H. influenzae. Macrolide antibiotics used to treat middle ear infections are erythromycin plus sulfisoxazole, azithromycin, and clarithromycin.
Duration of antibiotics — a 10-day course of oral antibiotics is usually effective in treating acute middle ear infections. However, studies have shown that a shorter course may be adequate, and a single dose of azithromycin has even been approved by the FDA. Experts suggest that a five- to seven-day course of antibiotics is appropriate for children six years and older who have mild to moderate middle ear infections. Children younger than two years should be treated for 10 days and those two years and older without a history of recurrent middle ear infections should be treated for five to seven days.
Treatment failure—with appropriate antibiotic treatment, the symptoms of a middle ear infection usually go away in 24 to 72 hours. If symptoms do not improve within 48 to 72 hours in a patient treated with antibiotics then another illness may be present or the initial therapy was not adequate. Inadequate therapy is usually related to infection with an organism resistant to beta-lactam antibiotics (H. influenzae and drug-resistant S. pneumoniae are becoming increasingly important), but infection with less common organisms, such as S. aureus, also must be considered, particularly in children with ear tubes.
Fluid may persist in the middle ear for longer periods, even when the antibiotics have sterilized the fluid and symptoms are no longer present. Persistent middle ear fluid after the symptoms of an infection has gone away does not mean that the treatment was a failure and it also does not mean that additional antibiotic is needed.
Experts recommend high-dose Augmentin (90 mg/kg per day amoxicillin and 6.4 mg/kg per day of clavulanate in two divided doses) when treatment failure is suspected. Alternatives to Augmentin for people with an allergy to penicillin include, cefdinir, cefpodoxime, cefuroxime, and ceftriaxone.
For patients with persistent and recurrent middle ear infections, further testing of the middle ear fluid should be done to reveal the specific organism involved in the infection. This involves sampling the middle ear fluid by a needle and a syringe. The needle is used to puncture the eardrum and middle ear fluid is collected and cultured. This procedure should be performed by an appropriately trained doctor who is comfortable performing the procedure in an awake child (unless there is access to sedation or anesthesia).
Insertion of small tubes through the eardrums, called tympanostomy tube placement, may be appropriate in some children with persistent and recurrent middle ear infections.
When a perforation occurs in the setting of middle ear infection, antibiotic ear drops may be an alternative to oral antibiotics for the child that is not seriously ill, has a normal immune system, and who is older than two years. However, antibiotics taken by mouth are preferred. Antibiotic drops with quinolone ear drops (ofloxacin or ciprofloxacin) is equal to antibiotics taken by mouth for treatment of ear discharge related to a middle ear infection in children with eardrum tubes or chronic ear drainage related an ear infections. This treatment has not been studied in children with middle ear infections and acute perforation.
Chronic perforations may also occur. A chronically infected middle ear or mastoid may result in persistent pus drainage. Patients with perforation that persists for three months or longer (with or without pus drainage) should be referred to an ENT doctor for further management. Prevention of this condition involves prompt and appropriate treatment of acute middle ear infection. It should be noted that the use antibiotics to prevent ear infections is not warranted.
Other Treatment Measures
Pain and fever is a common feature of middle ear infections. Ibuprofen (10 mg/kg three times per day) and acetaminophen (10 mg/kg three times per day) can be used to help relieve pain or treat fever.
Auralgan ear drops (combination of antipyrine, benzocaine, and glycerin) is a topical anesthetic or numbing agent that is commonly prescribed for pain relief.
An oral decongestant, such as pseudoephedrine, may relieve nasal congestion, and antihistamines may help patients with nasal allergy. However, the effectiveness of antihistamines and decongestants in treating middle ear infections has not been proven.
Over-the-counter cough and cold medications should not be given to infants and children younger than two years of age, due to the risk of life-threatening side effects.
Recurrent acute ear infections may be managed with long-term daily antibiotics. Single daily doses of sulfamethoxazole (500mg) or amoxicillin (250mg or 500mg) are given over a period of 1-3 months. Failure of this treatment to control infection is an indication for insertion of eardrum tubes.
Children who do not improve after 48 to 72 hours of antibiotics should be seen by their doctor to confirm the diagnosis of middle ear infection, evaluate for other illness that may be present, and to determine whether different antibiotics may need to be used.
Follow-up after symptoms have gone away depends on the child's age and underlying medical problems, especially in children with language delay or learning problems. The main reason for follow-up in these children is to see whether or not the middle ear fluid has gone away. Persistence of the middle ear fluid may cause hearing loss and, if chronic, may affect speech, language, and learning ability. In addition, chronic middle ear fluid may lead to the mistaken diagnosis of middle ear infection in children who develop separate unrelated illness on a later date.
Persistent middle ear fluid is common after symptoms of an acute ear infection go away. Patients with persistent middle ear fluid should follow-up with their doctor 8 to 12 weeks after middle ear infections have gone away (80 to 90 percent of middle ear fluid should go away by this time); this is especially important in the following groups of children:
-All children who are younger than two years.
-Children who are older than two years who have language or learning problems.
Children older than two years without language or learning problems should be followed up at their next health maintenance visit, or sooner if there are concerns regarding persistent hearing loss.