eMedicine Specialties > Otolaryngology and Facial Plastic Surgery > Middle Ear & Mastoid

Middle Ear, Otitis Media With Effusion: Differential Diagnoses & Workup

Author: Richard D Thrasher III, MD, Private Practice, McKinney, Texas
Contributor Information and Disclosures

Updated: Oct 26, 2009

Differential Diagnoses

Other Problems to Be Considered

Benign nasopharyngeal masses
Nasopharyngeal carcinoma
Adenoid hypertrophy
Congenital defects affecting the eustachian tube and its egress
Ciliary dyskinesia
Immunoglobulin G (IgG) subclass deficiencies

Workup

Laboratory Studies

• Traditionally, laboratory tests have rarely been used in the workup and diagnosis of otitis media with effusion (OME) unless another process is suspected. History taking and physical examination are sensitive and specific enough to facilitate accurate diagnosis and treatment of the disease. Obtaining cultures is not routine for OME but is discussed below with tympanocentesis in Procedures.
• In rare cases, the erythrocyte sedimentation rate is determined to rule out bony destruction, or the CBC count is assessed to rule out active infection.

Imaging Studies

• Plain radiography of the mastoid was once used effectively to screen for OME but is rarely used today given the sensitivity of history and physical examination in helping diagnose the disease.
• CT scanning is extremely sensitive and not needed for diagnosis. However, CT is important in attempting to rule out potential complications of otitis media (eg, mastoiditis, sigmoid sinus thrombosis, erosion of bone with intracranial extension) or unusual lesions (eg, cholesteatoma). CT scanning is particularly important in unilateral OME when a nasopharyngeal or eustachian tube mass must be ruled out.
• MRI is particularly useful in the workup for soft tissue masses that may be contributing to middle ear effusions because of its superior ability to delineate borders within soft tissues and help determine the extent of potential intracranial extension (often helpful in nasopharyngeal masses). In addition, MRI and its closely associated variants of magnetic resonance venography (MRV) and magnetic resonance arteriography (MRA) demonstrate complications such as thrombosis of the intracranial sinuses very well. However, when intracranial extension is present, either from invasion from the nasopharynx or the temporal bone, CT scanning helps define the bony anatomy more specifically and should be used in conjunction with MRI.

Other Tests

• Tympanometry is perhaps the most useful of all tests in association with OME.
  • Tympanometry reveals a type B result in 43% of cases of OME and a type C result in 47% of cases. A type B tympanogram is an imperfect measure of OME with 81% sensitivity and 74% specificity versus myringotomy. More recent studies (after 2001) have shown a higher rate of sensitivity and specificity, both around 90%. This is likely because of improvements in the technology used.
  • This test is particularly useful in small children whose external auditory canals may be too small or too collapsible to permit adequate visualization of the tympanic membrane. However, in those younger than 7 months, tympanometry is unreliable because of excessive compliance of the external auditory canal. The 2003 Agency for Healthcare Research and Quality (AHRQ) evidence report states that tympanometry results in children older than 4 years are reliable.
  • This test is a cost-effective adjunct to physical examination. Several studies have compared tympanometry with pneumatic otoscopy in terms of accuracy in detecting MEE when compared with the criterion standard of myringotomy. Nearly all studies show that pneumatic otoscopy is slightly more sensitive, at around 93%, but they differ on specificity, showing rates from 50-88%. Many of the conclusions in these protocols stated that the greatest use for tympanometry is in aiding the clinician in ruling out MEE for what appears to be an immobile tympanic membrane on examination.
• According to an updated clinical practice guideline on OME published in May 2004 by the joint efforts of the American Academy of Family Physicians, the American Academy of Otolaryngology-Head and Neck Surgery, and the American Academy of Pediatrics Subcommittee on Otitis Media with Effusion, audiology is a necessary component of the evaluation of certain patients with OME.³
  • The guidelines refer to recent randomized trials that have sought to determine if any long-term detrimental effects of OME are observed in children who have no hearing loss or risk factors for speech and language delay. When these children were followed for several years, no long-term detrimental effects were identified. Such results have shifted the paradigm for treatment so that chronic OME without hearing loss is no longer an absolute indication for the placement of tubes in children who are not at risk for language delays.
  • Studies examining hearing sensitivity in children with OME report that average pure tone hearing loss at 4 frequencies (500, 1000, 2000, and 4000 Hz) ranges from normal hearing to moderate hearing loss (0–55 dB). The 50th percentile is about 25 dB hearing level (HL), and approximately 20% of ears exceed 35 dB HL.
  • The committee stated that initial hearing testing can be done in a primary care setting for children aged 4 years or older but also stated that conventional audiometry with earphones is performed with a fail criterion of more than 20 dB HL at 1 or more frequencies (500, 1000, 2000, 4000 Hz) in either ear.
• Language testing has also been advocated in the clinical practice guidelines for children with hearing loss (pure tone average greater than 20 dB HL on comprehensive audiometric evaluation). Testing for language delays is important because communication is integral to all aspects of human functioning. Young children with speech and language delays during the preschool years are at risk for continued communication problems and later delays in reading and writing.

Procedures

• Tympanocentesis involves the aspiration of effusion from the middle ear.
  • This procedure can be performed as an office procedure, even in small children if necessary.
  • It can serve as both a therapeutic procedure and a diagnostic procedure.
  • The therapy consists of the removal of an MEE that can impair hearing or cause a sensation of aural fullness. Moreover, if performed in AOM, it may relieve a significant amount of pain.
  • The usefulness of tympanocentesis as a diagnostic procedure is greater with AOM that does not respond to antibiotics than in other conditions.
  • Tympanocentesis is useful to acquire specimens for culture in cases of AOM resistant to standard antibiotics and in immunocompromised hosts.
  • In RAOM, it may be used to obtain cultures and determine sensitivities.
• The criterion standard for documentation of a MEE is myringotomy, which has the advantage of increased exposure and better suctioning when compared to tympanocentesis. The primary disadvantage is a larger incision with a greater, albeit small, chance of persistent perforation or otorrhea.

Histologic Findings

In AOM, temporal bone studies reveal vascular dilatation and hyperplasia, inflammation and metaplasia of the mucosa, gland formation, edema, and infiltration with a mononuclear cell population. These same findings may be present, to a lesser degree, in OME.

• Search for CME/CE on This Topic »

• Middle Ear, Eustachian Tube, Inflammation/Infection (Otolaryngology and Facial Plastic Surgery)
• Middle Ear, Acute Otitis Media, Medical Treatment (Otolaryngology and Facial Plastic Surgery)
• Otitis Media (Emergency Medicine)
• Adenoidectomy (Otolaryngology and Facial Plastic Surgery)

• Guidelines Issued for Hearing Assessment in Infants, Children Beyond Neonatal Screening

• Responsiveness and Construct Validity of a Symptom Scale for Acute Otitis Media
• Novel Type of Streptococcus pneumoniae Causing Multidrug-Resistant Acute Otitis Media in Children
• Diving Medicine: A Review of Current Evidence

• Otitis Media Resource Center