Acute otitis media – otitis media

Acute otitis media (AOM) is a sudden onset infection of the air spaces of the middle ear and temporal bone and the mucosa covering the Eustachian tube and is one of the most common diseases of childhood. The majority of children have at least one episode of AOM until the age of 3. In the etiopathogenesis of the disease, many factors originating from both the child himself and the environment play a role.

Frequency
AOM can occur at any age, but it is generally a childhood disease and usually occurs between 3 months and 3 years of age. The incidence of AOM peaks between 6 and 11 months. Up to the age of one year, 60% of children experience AOM at least once and 17% at least 3 times, while 50-85% of children up to 3 years of age have had AOM. It has been suggested that AOM at an early age may be a risk factor for recurrent attacks. AOM is often bilateral in the first two years and there is no difference in the prevalence in boys and girls. After the age of five, AOM is usually unilateral, and the prevalence in children older than two years is higher in boys. Population-based studies conducted in Finland and the United States have found an increase in the incidence of AOM in the last 10-20 years, and this is thought to be related to the increase in sending children to day care. Compared to children who are cared for at home, upper respiratory tract infections and therefore AOM are more common in children who go to daycare. AOM is more common in autumn and winter, when viral respiratory infections, a well-known risk factor, are on the rise.

Pathogenesis and Risk Factors
AOM is an infectious disease of the middle ear and its attached cavities. The most important factors playing a role in its pathogenesis are infection, Eustachian tube dysfunction, immature immune system and allergy. The Eustachian tube plays a critical role in the health of the middle ear. The Eustachian tube balances the pressure difference between the air and the middle ear (ventilation), protects against nasopharyngeal pressure differences, ascending secretion and pathogens (protection), cleans secretions and debris towards the nasopharynx (clearance). Infants and young children are more prone to AOM because their Eustachian tubes are shorter, flexible, horizontal, and functionally weak.

The maturation of the Eustachian tube is a gradual process and may explain the decreased incidence of AOM after 6-7 years of age. In most cases, AOM begins with a viral upper respiratory tract infection involving the nasopharynx, impairing ventilation, clearance and drainage functions by causing congestion in the Eustachian tube. Following this, potentially pathogenic organisms (viruses and bacteria) that colonize the nasopharynx find their way into the middle ear cavity and multiply. Bacteria stimulate the inflammatory response responsible for clinical manifestations. The pathogenesis of AOM is summarized in figure 1. This immune response eradicates the infection with or without antibiotic therapy and relieves acute symptoms.

The risk factors for AOM include the nursery environment (correlation with the number of children), family history of recurrent otitis media, adenoid hypertrophy, early age of the first otitis media, not breastfeeding, age, genetic predisposition, crowded family environment, and season. Factors such as male gender, pacifier use, cigarette smoke exposure, and low socioeconomic status have also been highlighted, but these are of lesser relative risk and debate continues.

Although a recent study could not associate passive smoking with an increased risk of AOM, another study showed that ear infections were more common in children with passive and gestational cigarette exposure. Gastric contents in contact with the Eustachian tube have been shown to cause severe Eustachian dysfunction and middle ear disease. In a study that included one thousand three hundred and seventy-three twins, heredity was shown to be a risk factor for otitis media and Eustachian tube dysfunction.

Bacterial species that play a role in the pathogenesis of AOM have not changed significantly in the last 20-30 years. Streptococcus pneumonia, Moraxella catarrhalis and Haemophilus influenza are the most prominent pathogens in AOM. Group A Beta hemolytic streptococci, Staphylococcus aureus and anaerobic bacteria are less common. However, in newborn children, AOM is often caused by Gram (-) bacilli (E. coli, Klebsiella group and P. aeruginosa). Bluestone et al. The culture results of middle ear aspirates obtained from patients with AOM in a study conducted in 1996 are given in figure 2. Streptococcus pneumonia is involved in 35% of cases and is still the most prominent pathogen. This organism is often the cause of otalgia and fever and does not tend to resolve without medical treatment. Viruses alone or together with bacterial pathogens are among the causes of AOM.

All respiratory viruses may be involved, but viral otitis media is often caused by respiratory syncytial virus or rhinoviruses. Viral infections worsen the clinical and bacterial outcomes of otitis media. It is not yet clear how viruses worsen inflammation in the middle ear, but some inflammatory mediators were found to be higher in bacterial otitis media with viral co-infection than in bacterial otitis media alone.

Clinical Features of Acute Otitis Media
Ear pain in children is the most important symptom of AOM. In the literature, the rate of ear pain seen in AOM varies between 21% and 83%. Although ear pain is not a symptom specific to AOM, it is the only valuable symptom used to diagnose AOM. In one patient, complaints such as a feeling of fullness in the ear, hearing loss and imbalance are in favor of AOM. Ear pain is less common in children under the age of two. Irritability, constant crying, lethargy, sleepiness, playing with sick ears, loss of appetite, fever and vomiting are more prominent complaints in children under the age of two. Cough and rhinitis symptoms are frequently associated with AOM because 50-76% of cases are associated with the upper respiratory tract. Fever, like earache, is a variable finding in AOM. In studies, the rate of fever in AOM varies between 21% and 84%. Ear discharge is a sign of perforation. If there is a fever with the perforation, it decreases, the pain decreases, and if there is restlessness, it disappears. Hearing loss may be the prominent finding in older children and adults.

stages of AOM
There are five clinical stages of AOM: hyperemia stage, exudation stage, suppuration stage, resolving stage and complication stage.

Hyperemia Stage: The first change that occurs when the pathogen enters the middle ear is edema and fullness in the capillaries. During this time, the patient may have a feeling of fullness in the ear and mild hearing loss. Patients may have mild fever and ear pain. Young children may not be able to express ear pain. Otoscopic examination reveals hyperemia of the eardrum.

Exudation Phase: With the progression of the event, the middle ear and airspace mucosa are infiltrated with leukocytes, and then serum, fibrin and shaped blood elements from the vessels in the mucosa of the middle ear, EB and mastoid cells begin to transude into the middle ear and mastoid cells; a pressurized purulent effusion accumulates in the middle ear. Fever rises with the toxic effect of bacteria; Ear pain worsens and conductive hearing loss becomes evident. In this period, the eardrum is completely hyperemic, edematous and cambered. Ear pain is the most obvious complaint in this circuit. In children who cannot express their ear pain, restlessness, crying, eating and sleep disorders occur.

Suppuration Stage: With the effect of effusion and myringitis, which collects in the middle ear and mastoid space and loses the ability to drain due to the obstruction of the Eustachian tube, the eardrum perforates spontaneously. There is purulent discharge, initially bloody. With the occurrence of perforation, the pain quickly subsides and the fever subsides; edema in the eardrum disappears; red color turns on. However, conductive hearing loss continues until the effusion in the middle ear completely disappears.

Resolving (Coelescent mastoiditis) Mastoiditis Stage: Today, with effective antibiotic treatments, most of the AOMs progress to the maximum suppuration stage and begin to heal. However, infection and inflammation in the mastoid region continue in 1-5% of cases. Hypertrophy of the mastoid cell mucosa and pressure purulent effusion develops inside the mastoid cells; Over time, decalcification and melting occur in the bone tissue between the cells. Cells combine with each other to form large spaces. These spaces are filled with hypertrophic mucosa, granulation tissue, and purulent effusion. Initially, the symptoms seen in the exudation phase are mild. There is a constant flow, which increases especially at night and decreases during the day. Conductive hearing loss continues to increase. However, as the melting of the mastoid progresses and the purulent effusion accumulates there, the fever rises; pain, weakness, loss of appetite and restlessness reappear. In children, softening is observed in the posterior upper wall of the external auditory canal. There may be redness and swelling behind the ear and on the mastoid.

Complication Stage: Complications occur when infection and inflammation extend beyond the middle ear and mastoid space. Complications of AOM can be grouped under two main headings as intratemporal and intracranial. Mastoiditis, subperiosteal abscesses, petrous appendix, labyrinthitis, labyrinth fistula and facial paralysis are among the intratemporal complications, while meningitis, lateral sinus thrombosis, intracranial abscesses are intracranial complications.

Table 1. Stages of AOM

Table 2. Complications of AOM

Diagnosis in AOM
In most cases with AOM, the history and physical examination are sufficient for an accurate diagnosis. Otoscopy of AOM is typical, the appearance of the eardrum differs according to the stage of the disease. Three elements are required for the diagnosis of AOM: sudden onset of the disease, presence of middle ear effusion, and signs and symptoms of middle ear inflammation. Among them, the bulging of the eardrum has the most predictive value. Some clinical signs and symptoms of AOM have been associated with certain pathogens. It has been reported that S. pneumoniae causes high fever, more cambering and high peripheral leukocyte count, unlike other pathogens, and H. influenzae is often associated with conjunctivitis. Additional diagnostic work-up is performed when the diagnosis is uncertain, treatment is inadequate, and complications are suspected. Diagnostic procedures include audiological examinations such as pneumatic otoscopy, tympanometry, audiometry and acoustic reflectometry, radiological examinations such as magnetic resonance and computed tomography, surgical procedures (myringotomy, tympanocentesis) and microbiological examinations.

Medical Treatment of AOM
AOM is an infection with a high rate of spontaneous recovery. In recent meta-analyses, it has been reported that approximately 80% of children show spontaneous clinical improvement within 2-14 days without any complications, with symptomatic treatment without antibiotics. In observational and randomized studies, 70-90% of AOM patients treated with placebo or not on medication have been shown to resolve spontaneously within 7-14 days. In addition, the incidence of acute mastoiditis less than 0.1% indicates that there is no increase in the incidence of complications and sequelae in cases where antibiotics are not used. The high rate of spontaneous recovery requires that some of the patients should be followed up first, and nowadays only pain treatment is given for AOM in many countries, whereas antibiotic treatment is reserved only for resistant cases.

While deciding on antibiotic treatment, it is not known which patient will benefit from this treatment and which will not, due to the high rate of spontaneous recovery. Especially in some central and northern European countries, in children older than 2 years, if the fever and pain are not very high, the patient is followed for 3 days without antibiotics, and if the patient’s signs and symptoms still persist after the 3rd day, then empirical antibiotics are given. The American Academy of Pediatrics and the American Academy of Family Medicine have published a guideline and recommended the age-adjusted approach to AOM. (Table 3) According to these recommendations, antibiotic therapy should be given to all children younger than 6 months, even if the diagnosis of AOM is suspected. In children aged 6 months to 2 years, follow-up is recommended if the diagnosis is uncertain and their symptoms are not severe. For children over 2 years of age, follow-up is recommended if the symptoms are not severe, even if the diagnosis is definite.

When choosing a medical treatment, attention is paid to its clinical and microbiological efficacy, lack of side effects and toxicity, dosage and price. The drug to be used in AOM should pass into the middle ear very well and should eradicate the most common causative pathogens. Currently, there is no drug that can eradicate all pathogens in the etiology of AOM. Treatment is often empirical and given with the most common bacteria in mind. With its efficacy against S. pneumonia (including strains not susceptible to penicillin but eradicated with high-dose amoxicillin) and good pharmacotherapy profile, amoxicillin remains the first choice in uncomplicated AOM. While the recommended dose for children at moderate risk for resistant pneumococci is 45mg/kg/day, the recommended dose for high-risk children is 80-90 mg/kg/day to reach the maximum concentration in the middle ear. Although β-lactamase-producing bacteria (M. catarrhalis and H. influenza) cannot be completely eradicated by amoxicillin, the infection caused by these organisms is more harmless and often resolves without incident. If the patient cannot use amoxicillin treatment due to penicillin allergy, alternative drugs for first-line treatment are erythromycin, trimethoprim-sulfometexazole and azithromycin today. If symptoms do not improve 72 hours after antimicrobial therapy, treatment failure is mentioned. In this case, second-line treatment is started. Second-line antibiotics can be given directly as the first choice in the neonatal period due to the difference in the causative pathogens and the patient’s current history of use of amoxicillin in the last month. Amoxicillin-clavulanic acid, cefuroxime axetil and intramuscular ceftriaxone are among the second-line treatment options. In children older than two years of age and in mild cases, shorter duration of treatment is appropriate, but the duration of treatment is typically up to 10 days, depending on the antimicrobial agent used. Azithromycin therapy is given for 5-7 days.

Table 3. Recommendations for the treatment of AOM in children (34)

a Severe illness moderate to severe earache or fever

b Definitive diagnosis of AOM requires 3 criteria: (1) sudden onset, (2) signs of middle ear effusion, (3) signs and symptoms of middle ear inflammation

Surgical Treatment in AOM
Although careful observation and medical management is the first step in the management of AOM, surgical treatment should be considered in recurrent AOM and suppurative complications such as osteitis and mastoiditis. Surgical modalities such as tympanostomy tube or tubeless myringotomy, tympanocentesis and adenoidectomy can be used in the treatment of AOM. (Figure 6) Studies have failed to show that myringotomy with or without antibiotic therapy is superior to antibiotic therapy. (33) Therefore, the primary value of tympanocentesis is that it allows culture to guide antibiotic therapy. Culture is indicated if there is a possibility of septicemia, if there is no improvement despite switching to second-line antibiotics, if the possibility of temporal bone or intracranial complications has emerged, and in children with certain systemic diseases.

Prevention of AOM
Conjugated pneumococcal vaccines reduce the incidence of AOM by 6-8%, so AOM caused by vaccine-associated strains is reduced by 56-67%. It has been shown that vaccinated children need 20.1% less ventilation tube administration than unvaccinated children. However, when conjugated pneumococcal vaccines became routine practice, it was reported that pneumococci were replaced by vaccine-related pneumococcal strains or H. influenza or M. Catarrhalis. It has been reported that the number of AOM due to H. influenza has increased. Today, conjugated pneumococcal vaccine is recommended for children younger than 2 years and older children with serious risk factors for recurrent AOM.

Modifiable risk factors should be reduced by the patient’s family. Exposure to cigarette smoke should be eliminated and pacifier use should be restricted. The group in the nursery setting should be reduced and if allergy is suspected, it should be evaluated and treated.