Acute Otitis Media (AOM)

An infection of the middle ear canal is known as acute otitis media. Acute otitis media, chronic suppurative otitis media, and otitis media with effusion are all types of otitis media. After upper respiratory infections, acute otitis media is the second most common pediatric condition in the emergency room. Otitis media can affect anyone at any age; however, it is most frequent in children aged 6 to 24 months.

A viral, bacterial, or coinfection disease of the middle ear is possible. Streptococcus pneumonia is the most prevalent bacterial species that cause otitis media, followed by non-typeable Hemophilus influenzae and Moraxella catarrhalis. Pneumococcal organisms have evolved into non-vaccine serogroups after the advent of conjugate pneumococcal vaccinations. The respiratory syncytial virus, coronaviruses, influenza viruses, adenoviruses, human metapneumovirus, and picornaviruses are the most prevalent viral culprits causing otitis media.

Practically, otitis media is identified by combining objective findings on a medical examination (with otoscopy) with the patient's history and current signs and symptoms. To support the diagnosis of otitis media, diagnostic equipment such as a pneumatic otoscope, tympanometry, and acoustic reflectometry are provided. When compared to plain otoscopy, pneumatic otoscopy is the most accurate and has greater sensitivity and specificity, while tympanometry and other techniques can help with diagnosis if pneumatic otoscopy is not accessible.

Antibiotic treatment for otitis media is debatable and necessarily related to the subtype of otitis media. Suppurative material from the middle ear can spread to nearby anatomical regions, causing consequences such as tympanic membrane perforation, mastoiditis, labyrinthitis, petrositis, meningitis, cerebral abscesses, hearing problems, lateral and cavernous sinus thrombosis, and more.   As a result, particular recommendations for the treatment of otitis media have been developed. High-dose amoxicillin is the backbone of treatment in the United States for children with a proven confirmation of acute otitis media, and it has been found to be most beneficial in kids under the age of two. In countries such as The Netherlands, the treatment plan is watchful waiting, and if the problem persists, antibiotics are prescribed. Nevertheless, due to the risk of persistent middle ear effusion and its influence on hearing and speech, as well as the dangers of complications, the idea of cautious watching has not received complete acceptance in the United States and other nations. In individuals with otitis media, painkillers such as non-steroidal anti-inflammatory drugs like acetaminophen can be administered alone or in conjunction to produce effective pain relief.

Acute Otitis Media Related Anatomy

The relationships between the structures behind the membrane determine the cutting of the tympanic membrane. An imaginary line formed vertically along the long process of the malleus (one of the middle ear ossicles) and extending to the inferior annulus, as well as a horizontal line at the umbo, can be used to divide the tympanic membrane (eardrum) into quadrants. generally, all quadrants can be securely cut, with the exception of the posterior superior portion, which contains the incus and stapes, which could be harmed accidentally by cutting in this location. The pars flaccida, which is located above the pars tensa, should be avoided.

The facial nerve and the round window are two more structures that are normally shielded from all but the clumsiest of doctors, the former due to its lofty position in the middle ear and the latter due to the overhanging hole.

Generally, tubes are put proximally, either superiorly or inferiorly. Because the posterior portions are deeper and have more vibratory action, they attenuate the sound more effectively. Any cut made proximally should avoid exposing the malleus, malleolar ligament, or annulus; this exposes the malleus, malleolar ligament, or annulus, which increases the likelihood of perforations persisting following tube extrusion.

Epidemiology

Otitis media is a global disease and is shown to be more prevalent in boys than in girls. Due to a lack of documentation and varying frequencies throughout many different geographical areas, determining the exact number of cases every year is challenging. Otitis media is most common between the ages of 6 and 12 months, then reduces after that. About 80 percent of all children will get otitis media at some point in their lives, and between 80 and 90 percent of all children will develop otitis media with an effusion before reaching primary school. Adults are less likely than children to get otitis media, while it is more frequent in certain subgroups, such as those with a history of recurrent otitis media as a kid, cleft palate, immunodeficiency, or immunocompromised state.

Pathophysiology

The most significant preceding event associated with acute otitis media appears to be the blockage of the eustachian tube. An upper respiratory tract infection affecting the nasopharynx causes a large bulk of acute otitis media episodes.

Viral and Bacterial Infection

The infection is usually caused by a virus, but allergies and other inflammatory disorders that affect the eustachian tube can also cause this. The nasopharyngeal inflammation spreads to the medial side of the eustachian tube, causing stagnation and inflammation, which changes the pressure in the middle ear. In relation to ambient pressure, these alterations might be either negative or positive.

Through direct transmission from the nasopharynx via regurgitation, aspiration, or active insufflation, harmful microorganisms can invade the typically sterile middle ear area.

The response is the initiation of an initial acute inflammation within the middle ear canal, which is described by characteristic vasodilation, exudation, leukocyte invasion, phagocytosis, and local immunologic reactions, resulting in the clinical manifestations of acute otitis media.

The eustachian tube is patulous or hypotonic in a small percentage of otitis-prone kids. Children with neuromuscular diseases or anomalies of the first or second arch are more likely to be too wide, allowing nasopharyngeal secretions to reflux into the cleft of the middle ear.

Most microorganisms must cling to the mucous membrane of hollow organs like the ear or sinus to become harmful. The capacity of microorganisms to become infectious in the nasopharynx, eustachian tube, and middle ear cleft may be facilitated by viral infections that destroy and damage mucosal linings of the respiratory system.

This approach could explain why, in children with acute otitis media, viral antigens are frequently identified from middle ear aspirates but the infectious virus is seldom identified. Evidence has also been published demonstrating that mucosal damage caused by endotoxins released by bacterial pathogens may improve pathogen attachment to mucosal membranes in a similar way.

Immunologic Factors

The frequency of acute otitis media and its consequences may be influenced by the immunologic response. Despite the fact that the majority of research has concentrated on the immunologic features of otitis media with effusion, specific links between acute otitis media and the patient's immunological condition have been established, as follows:

• Antibodies may aid in the clearing of a middle ear effusion following an acute infection.
• Prior exposure or immunization may act as a prophylactic measure by preventing germs from colonizing the nasopharynx.
• Antibodies formed during infection may help to prevent or alter subsequent infections; however, antibodies against Streptococcus pneumonia and Hemophilus influenza are polysaccharide-based, and the ability to create them takes a long time to develop unless they are coupled to proteins.
• Recurrent otitis media can be caused by minor or temporary immunological abnormalities.

The immunoglobulins and the patient's capacity to produce them have received a lot of attention. Antibodies against polysaccharide components are mediated by immunoglobulin G2 and immunoglobulin G4; deficits in the production of these antibodies inevitably result in otitis media. Many Down syndrome children have impaired immunoglobulin A, IgG2, or IgG4 activity, which contributes to the higher risk of chronic rhinitis and otitis media.

Acute otitis media immunologic features are not limited to the middle ear. The nasopharynx is involved in the etiology of acute otitis media, and immunologic changes in this lymphoid tissue give some protection against infections by inhibiting them from adhering to mucosal membranes. Antibodies against pneumolysin toxin produced by pneumococcal autolysis found in the nasopharynx tend to prevent infiltration by healthy streptococcus pneumonia.

Acute Otitis Media Causes

Viral Infection

The respiratory syncytial virus is a big RNA paramyxovirus that is most typically related to bronchiolitis and pneumonia in children, but it can also cause acute respiratory disease in adults.  In northern regions, the respiratory syncytial virus is generally recognized during seasonal epidemics in the winter and early spring, although it should be evaluated in any neonate with lethargy, irritability, or apnea, with or without otitis media. Respiratory symptoms are frequently more obvious in older infants and toddlers, making diagnosis straightforward.

The respiratory syncytial virus was discovered early on as a virus that appeared to cause long-term respiratory problems, especially asthma, in up to half of bronchiolitis patients. Children with congenital cardiac disease, cystic fibrosis, immunodeficiency, bronchopulmonary dysplasia, or prematurity of fewer than 37 weeks gestational age may be especially vulnerable to respiratory syncytial virus.

Only high-risk youngsters should receive RSV-specific intravenous immunoglobulin prophylaxis. When managing a kid with simultaneous pneumonia or other systemic disease and otitis media, the physician must verify that all components of the child's condition are properly diagnosed and managed. In some cases, ear drainage via tympanocentesis or myringotomy is required for culture and treatment. Drainage is required in infants suspected of being infected or in youngsters who are immunocompromised.

Bacterial Infection

In at least half of the children with acute otitis media, harmful bacteria are isolated from the middle ear exudate, and bacterial DNA or cell wall material is discovered in another quarter to a third of previously sterile samples. The majority of acute otitis media episodes in people older than 6 weeks are caused by four bacteria: S pneumoniae, H influenzae, Moraxella catarrhalis, and Streptococcus pyogenes.

1. Streptococcus pneumonia. It is the most prevalent causative organism in children of all ages who develop acute otitis media and aggressive bacterial infections. It's a gram-positive diplococcus with 90 known serogroups (based on the polysaccharide epitope), the prevalence of which varies by age and region. Various investigations have found that these bacteria are responsible for 30-40 percent of isolates on primary culture, while pneumococcal antigens are also obtained from around a third of sterile samples.
2. Hemophilus influenza. It is the second most commonly recovered bacteria in middle ear aspirates from individuals with acute otitis media, accounting for almost 20 percent of cases in preschool children. Otitis-prone children, older children, and adults who have had the pneumococcal immunization may have a higher incidence.
3. Moraxella catarrhalis. It is a gram-negative bacterium that is found in the human upper respiratory tracts' natural flora. The release of numerous lactamase isoenzymes, which can be plasmid or chromosomal in nature and inducible, confers resistance.
4. Streptococcus pyogenes. Streptococcal toxic shock syndrome, which includes coagulation abnormalities, soft tissue destruction or fasciitis, desquamating erythema, and hepatic or kidney dysfunction, may be linked to S pyogenes. It is mainly a pharyngeal pathogen, with over 80 different strains discovered. With the advancement of primary care and the introduction of quick identification tests, effective first-line therapy against this bacterium, which has demonstrated little potential to build antibiotic resistance, is now the norm.
5. Bacterial pathogens in neonates. The causative bacteria most usually responsible for sepsis and meningitis in the perinatal period are Escherichia coli, Enterococcus species, and group B streptococci. These drugs are frequently collected from the middle ear, while the total number of newborns with acute otitis media is likely less than 10 percent. Streptococcus pneumonia is still the most frequent cause of acute otitis media in people of all ages, including newborns. The nonencapsulated Hemophilus influenzae and non-typeable variants, which are the second most prevalent viruses isolated from the ear, may be aggressive in these newborns.

Risk Factors

The following are the possible risk factors associated with acute otitis media:

• Prematurity and low birth weight
• Young age
• Early-onset
• Family history
• Native American and Australian aborigine
• Altered immunity
• Craniofacial abnormalities
• Neuromuscular disease
• Allergy
• Day-care
• Crowded living conditions
• Low socioeconomic status
• Tobacco and pollutant exposure
• Use of pacifier
• Prone sleeping position
• Fall or winter season
• Absence of breastfeeding

Acute Otitis Media Symptoms

The course of acute otitis media varies according to age, although there are a few common characteristics that appear during the otitis-prone periods.

Irritability or feeding difficulties in the newborn may be the only signs of a septic infection. Fever (with or without a coexisting upper respiratory tract infection) and otalgia (or ear pain) become more common in older children. Teething discomfort or pharyngitis might resemble similar symptoms, which are not unique to acute otitis media.

Hearing loss becomes a constant characteristic of acute otitis media and otitis media with effusion in older children and adults, with complaints of ear stuffiness occurring even before the presence of middle ear effusion. Adults with external otitis, tooth abscess, or pain transferred from the temporomandibular joint experience ear pain without hearing loss or fever. As the dental alignment is altered by orthodontic appliances, referred pain is common.

Acute Otitis Media Diagnosis

A physical exam and the use of an otoscope, preferably a pneumatic otoscope, should always be used to diagnose otitis media.

Laboratory Tests

Rarely is a laboratory examination required. In infants younger than 3 months old who have a fever with no evident cause other than concomitant acute otitis media, a thorough sepsis workup may be required. Laboratory tests may be required to confirm or rule out the presence of any associated systemic or congenital disorders.

Imaging Studies

If intra-temporal or cerebral problems are a concern, imaging tests are not recommended.

When a complication of otitis media is suspected, a computed tomography scan of the temporal bones may reveal mastoiditis, epidural abscess, sigmoid sinus thrombophlebitis, meningitis, brain abscess, subdural abscess, ossicular disease, and cholesteatoma.

Fluid collections, particularly in the middle ear, may be detected using magnetic resonance imaging.

Tympanocentesis

To prove the presence of middle ear effusion, tympanocentesis can be done, accompanied by culture to determine the microorganisms. Tympanocentesis can help with diagnosis and treatment choices, but it's only used in the most severe or refractory cases.

Other Tests

Middle ear effusion can also be assessed using tympanometry and acoustic reflectometry.

Acute Otitis Media Treatment

Once an acute otitis media diagnosis has been made, the goal of treatment is to relieve pain while also treating the infectious disease with antibiotics. Pain relief can be achieved with non-steroidal anti-inflammatory medications, such as acetaminophen. Antibiotics are controversial in the early stages of otitis media, and recommendations vary by region, as stated above. In European countries, watchful waiting is used, but no greater consequences have been recorded. However, in the United States, attentive waiting is not widely practiced. If suppurative acute otitis media is present, oral antibiotics are prescribed to treat the bacterial infection, with high-dose amoxicillin or a second-generation cephalosporin being the first-line medications. If there is a tympanic membrane perforation, ototopical antibiotics safe for middle-ear application, such as ofloxacin, should be used instead of systemic antibiotics, because ototopical medications produce considerably higher levels of antibiotics with no adverse reactions.

In both infants and adults who are not allergic to penicillin, high-dose amoxicillin for 14 days is the antibiotic of choice when a bacterial cause is suspected. Because of its high concentration in the middle ear, amoxicillin has excellent efficacy in treating acute otitis media. The American Academy of Pediatrics recommends azithromycin (10 mg/kg) or clarithromycin (15 mg/kg/day divided into 2 doses) in cases with penicillin allergy. Cefdinir (14 mg/kg/day in one or two doses), cefpodoxime (10 mg/kg/day, once daily), and cefuroxime (30 mg/kg/day in two divided doses) are further choices for penicillin-allergic patients.

High-dose amoxicillin-clavulanate (90 mg/kg/day of amoxicillin portion, 6.4 mg/kg/day of clavulanate in two separate dosings) should be administered to patients whose symptoms do not resolve after therapy with high-dose amoxicillin. Ceftriaxone (50 mg/kg/day) for four days, either intravenous or intramuscular injections, as a substitute to oral antibiotics in children who are vomiting or in conditions where oral antibiotics cannot be given. Antihistamines and systemic steroids have not been found to provide any substantial benefit.

According to the American Academy of Pediatrics, children who have had four or more bouts of acute otitis media in the previous year should be considered candidates for myringotomy with tube installation. Repeated infections requiring antibiotics are a sign of Eustachian tube malfunction, and insertion of a tympanostomy tube permits for adequate hearing and aeration of the middle ear cavity. Moreover, if the patient develops otitis media while the tube is in place, ototopical antibiotic solutions can be used instead of systemic antibiotics to treat the infection.

Acute Otitis Media Complications

Intra-temporal Complications

• Hearing loss 
• Tympanic membrane perforation 
• Chronic suppurative otitis media
• Cholesteatoma
• Tympanosclerosis
• Mastoiditis
• Petrositis
• Labyrinthitis
• Facial paralysis
• Cholesterol granuloma
• Infectious eczematoid dermatitis

Intracranial Complications

• Meningitis
• Subdural empyema
• Brain abscess
• Extradural abscess
• Lateral sinus thrombosis
• Otitic (structure in the middle ear) hydrocephalus

Acute Otitis Media Prognosis

The majority of people with otitis media have a good prognosis. In recent times, death from acute otitis media is a rare occurrence. Early detection and treatment have led to improved prognosis for this condition in industrialized countries due to increased access to healthcare. Antibiotic therapy is the cornerstone of treatment. The progress of the disease is influenced by a number of prognostic variables. When compared to children who develop acute otitis media in seasons other than winter, children who appear with less than three episodes are three times more likely to have the symptoms treated with a single course of antibiotics.

Complications in children can be refractory to treatment, and often have a high recurrence rate. While intra-temporal and intracranial problems are uncommon, they have high mortality rates.

Children with a history of prelingual otitis media are at risk for conductive hearing loss, which can range from mild to moderate. Strident or high-frequency consonants, such as sibilants, are generally difficult to perceive in children with otitis media in the first two years of life.

Conclusion

Acute otitis media is frequently treated in an outpatient or clinic context. It can, however, be best served by an interdisciplinary team approach that includes physicians, family members, audiologists, and/or speech pathologists. Early detection and treatment reduce the likelihood of complications, which contributes to positive patient outcomes.