Acute Otitis Media

Article Author:
Amina Danishyar
Article Editor:
John Ashurst
Updated:
7/30/2019 4:09:54 PM
PubMed Link:
Acute Otitis Media

Introduction

Otitis media is defined as an infection of the middle ear fluid and is the second most common pediatric diagnosis in the emergency department following upper respiratory infections. Although otitis media can occur at any age, it is most commonly seen between the ages of 6 to 24 months.

Infection of the middle ear can be due to viral, bacterial or coinfection with both. The most common bacterial organisms causing otitis media are Streptococcus pneumoniae, followed by non-typeable Haemophilus influenzae (NTHi), and Moraxella catarrhalis. Following the introduction of the conjugate pneumococcal vaccines, the pneumococcal organisms have evolved to non-vaccine serotypes. The most common viral pathogens of otitis media include the respiratory syncytial virus (RSV), coronaviruses, influenza viruses, adenoviruses, human metapneumovirus, and picornaviruses.

Otitis media is diagnosed clinically considering objective findings on physical exam combined with presenting signs and symptoms. Several diagnostic tools are available such as a pneumatic otoscope, tympanometry, and acoustic reflectometry to aid in the diagnosis of otitis media. Pneumatic otoscopy is the most reliable and has a higher sensitivity and specificity as compared to otoscope, tympanometry and other modalities.

Treatment of otitis media with antibiotics is controversial. Without proper treatment, suppurative fluid from the middle ear can extend to the adjacent anatomical locations and result in complications such as TM perforation, mastoiditis, labyrinthitis, petrositis, meningitis, brain abscess, hearing loss, lateral and cavernous sinus thrombosis and others. Due to the controversy surrounding treatment and the risks of complications, there are guidelines in place for the treatment of OM.  In the United States, the mainstay of treatment of an established diagnosis of otitis media is high dose amoxicillin and has been found to be most beneficial in children under two years of age. Treatment in countries like the Netherlands is initially watchful waiting, and if unresolved, antibiotics are warranted. However, the concept of watchful waiting has not gained full acceptance in the United States. Analgesics such as non-steroidal drugs and acetaminophen can be used alone or in combination to achieve effective pain control in patients with otitis media.

Etiology

Infectious, allergic, and environmental factors contribute to otitis media.

The causes include:

  • Immune due to HIV, diabetes, and other immuno-deficiencies
  • Genetic predisposition
  • Mucins which include abnormalities of this gene expression, especially upregulation of MUC5B
  • Anatomic abnormalities of the palate and tensor veli palatini
  • Ciliary dysfunction
  • Cochlear implants
  • Vitamin A deficiency
  • Bacterial pathogens, Streptococcus pneumoniae, Haemophilus influenza, and Moraxella (Branhamella) catarrhalis, are responsible for more than 95%
  • Viral pathogens such as respiratory syncytial virus, influenza virus, parainfluenza virus, rhinovirus, and adenovirus
  • Allergies
  • Lack of breastfeeding
  • Passive smoke exposure
  • Daycare attendance
  • Lower socioeconomic status

Epidemiology

Otitis media is a global problem and is found to be slightly more common in males than in females. The specific number of cases per year is difficult to determine due to the lack of reporting and varied incidence across many different geographical regions. The peak incidence of otitis media occurs between six and twelve months of life and declines after age five. Approximately 80% of all children will experience a case of otitis media during their lifetime and between 80%, and 90% of all children will have otitis media with an effusion before school age. Otitis media is less common in adults than in children, unless it occurs in immunocompromised adults.

Pathophysiology

Otitis media initially starts as an inflammatory process following a viral upper respiratory tract infection involving the mucosa of the nose, nasopharynx and Eustachian tube. Due to narrow anatomical space, the edema caused by the inflammatory process obstructs the narrowest part of the Eustachian tube leading to a decrease in ventilation. This leads to a cascade of events such as an increase in negative pressure in the middle ear and buildup of mucosal secretions allowing for colonization of bacterial and viral organisms in the middle ear. The growth of these microbes in the middle ear then leads to suppuration which is demonstrated as the clinical signs of acute otitis media such as bulging or erythematous tympanic membrane and middle ear fluid.

Several risk factors play a role in causing Eustachian tube dysfunction predisposing children to otitis media. The most common risk factor is a preceding upper respiratory tract infection. Other risk factors include male sex, adenoid hypertrophy (obstructing), allergy, daycare attendance, environmental smoke exposure, pacifier use, immunodeficiency, gastroesophageal reflux, and even genetics. Traditionally it was believed that breastfeeding is protective; however, recent studies in Denmark did not support such benefit as increased breastfeeding in a population did not change the incident of otitis media.

History and Physical

Although one of the best indicators for otitis media is otalgia, many children with otitis media can present with non-specific signs and symptoms which can make the diagnosis challenging. These symptoms include irritability, headache, disturbed or restless sleep, poor feeding/anorexia, vomiting, or diarrhea. Approximately two third of the patients present with fever, which is typically not greater than 40 C.

Diagnosis of otitis media is primarily based on clinical findings combined with supporting signs and symptoms as described above. No lab test or imaging needed. According to guidelines set forth by American Academy of Pediatrics, evidence of moderate to severe bulging of the tympanic membrane, or new onset of otorrhea not caused by otitis externa or mild tympanic membrane (TM) bulging with recent onset of ear pain or erythema is required for the diagnosis of acute otitis media. These criteria are intended only to aid primary care clinicians in the diagnosis and proper clinical decision making but not to replace clinical judgment.

Any of the diagnostic tools such as an otoscope, pneumatic otoscope, tympanometry, and acoustic reflectometry can be used for visual examination of the middle ear. Otoscope examination is usually the first and more convenient way of examining the ear canal for erythema or loss of landmarks indicating middle ear effusion. However, the pThe preferred method of detecting middle ear effusion and obtaining culture sample for bacterial etiology is tympanocentesis, but it is rarely used in a primary care setting.

Evaluation

The diagnosis of otitis media should always begin with a physical exam and use of a pneumatic otoscope.

Laboratory Studies

Laboratory evaluation is rarely necessary. A full sepsis workup in infants younger than 12 weeks with fever and associated acute otitis media is often necessary. Laboratory studies may be needed to confirm or exclude possible related systemic or congenital diseases.

Imaging Studies

Imaging studies are not indicated unless intratemporal or intracranial complications are a concern.

  • When an otitis media complication is suspected, computed tomography of the temporal bones may identify mastoiditis, epidural abscess, sigmoid sinus thrombophlebitis, meningitis, brain abscess, subdural abscess, ossicular disease, and cholesteatoma.
  • Magnetic resonance imaging may identify fluid collections, especially in the middle ear collections.

Tympanocentesis

Tympanocentesis may be used to determine the presence of middle ear fluid, followed by culture to identify pathogens.

Tympanocentesis can improve diagnostic accuracy and guide treatment decisions.

Neonates or children who appear toxic or those that are at higher risk should undergo early tympanocentesis with culturing.

Other Tests

Tympanometry an acoustic reflectometry may also be used to evaluate for middle ear effusion.

Treatment / Management

When the diagnosis of otitis media is established, the goal of treatment is to control pain and to target the infectious process with antibiotics. Non-steroidal anti-inflammatory drugs (NSAIDs) and acetaminophen can be used in combination or alone to achieve pain control as they have been shown to be superior to placebo. There are controversies about prescribing antibiotics in early otitis media. Watchful waiting is practiced in European countries with no increased incidence of complications. However, watchful waiting has not gained wide acceptance in the United States. Reportedly, the presence of concomitant viral infection and bacterial infection decreased the efficacy of the antibiotic treatment due to increased inflammation and decreased antibiotic penetration of the middle ear. Hence, watchful waiting in the initial stages of otitis media is recommended.

When a bacterial etiology is suspected, the antibiotic of choice is a for ten days in both children and adult patients who are not allergic to penicillin. Amoxicillin has good efficacy in the treatment of otitis media due to its high concentration in the middle ear. In cases of penicillin allergy, the American Academy of Pediatrics (AAP) recommends azithromycin as a single dose of 10 mg/kg or clarithromycin (15 mg/kg per day in 2 divided doses). Other options for penicillin-allergic patients are cefdinir (14 mg/kg per day in 1 or 2 doses), cefpodoxime (10 mg/kg per day, once daily), or cefuroxime (30 mg/kg per day in 2 divided doses).

Those patients whose symptoms do not improve after treatment with high dose amoxicillin, high-dose amoxicillin-clavulanate (90 mg/kg per day of amoxicillin component, with 6.4 mg/kg per day of clavulanate in 2 divided doses) should be given. In children who are vomiting or if there are situations in which oral antibiotics cannot be administered, ceftriaxone (50 mg/kg per day) for 3 consecutive days either intravenously or intramuscularly is an alternative option. Systemic steroids and antihistamine have not been shown to have any significant benefit.


References