Diagnostic Criteria for Otitis Media
Acute otitis media (AOM) requires three essential elements for diagnosis: acute onset of signs and symptoms, presence of middle ear effusion (MEE), and signs of middle ear inflammation. 1, 2
Definitive Diagnostic Criteria
The diagnosis of AOM is established when all three of the following are present:
1. Acute Onset of Symptoms
- Rapid onset of ear pain (otalgia) in older children 1, 2
- In preverbal children: ear tugging/rubbing/holding, excessive crying, irritability, or changes in sleep/behavior patterns 1, 2
- Fever (though not always present) 2
- Restless sleep, nonspecific respiratory or gastrointestinal symptoms 1
Critical pitfall: Clinical history alone is poorly predictive of AOM, especially in younger children, and should never be used as the sole diagnostic criterion. 1, 2
2. Presence of Middle Ear Effusion (MEE)
MEE must be documented by at least one of the following findings:
- Bulging of the tympanic membrane 1, 2
- Limited or absent mobility of the tympanic membrane (best assessed with pneumatic otoscopy) 1, 2
- Air-fluid level behind the tympanic membrane 1, 2
- Otorrhea not caused by otitis externa 1, 2
3. Signs of Middle Ear Inflammation
At least one of the following must be present:
- Distinct erythema of the tympanic membrane 1, 2
- Ear pain (otalgia) that suggests middle ear inflammation 1, 2
Stringent Diagnostic Criteria (Highest Certainty)
The American Academy of Pediatrics endorses stringent criteria for definitive AOM diagnosis: 1, 2
- Moderate to severe bulging of the TM, OR 1, 2
- New onset of otorrhea not due to otitis externa, OR 1, 2
- Mild bulging of the TM with recent onset (<48 hours) of ear pain or intense erythema of the TM 1, 2
Otoscopic Findings and Their Diagnostic Value
Pneumatic otoscopy is the primary diagnostic tool and is essential for accurate diagnosis. 2 The following findings have specific diagnostic characteristics:
- Bulging TM: Highest specificity (97%) for bacterial AOM; strongly associated with bacterial pathogens 1, 2
- TM mobility (impaired): Highest combined sensitivity and specificity (95% and 85%, respectively) 1, 2
- Cloudy TM: High sensitivity (74%) and specificity (93%) 1, 2
- TM color (hemorrhagic, strongly red, or moderately red): Correlates with AOM 1, 2
- Slightly red TM alone: Not diagnostically helpful and often due to crying, viral infection, or cerumen removal attempts 1, 3
Critical pitfall: Erythema of the eardrum alone should never be the sole basis for diagnosing AOM, as it is often the result of viral infection, crying, or instrumentation. 3
Diagnostic Tools
Essential Equipment
- Pneumatic otoscopy: Primary and essential diagnostic method 2
- Fresh bulb and good power source in the otoscope 3
- Clear view of the TM (cerumen must be removed if obstructing) 1, 3
Supplementary Tools
- Tympanometry: Can supplement but not replace pneumatic otoscopy; useful when otoscopic findings are uncertain 1, 2
- Acoustic reflectometry: May supplement examination 1
- Imaging: Not indicated for uncomplicated AOM diagnosis 2
Distinguishing AOM from Otitis Media with Effusion (OME)
This distinction is critical to avoid unnecessary antibiotic use: 1, 2
- AOM: Acute symptoms + MEE + signs of inflammation 1, 2
- OME ("glue ear"): MEE without acute symptoms or signs of acute inflammation 1, 2
Common pitfall: When OME is mistakenly identified as AOM, antibiotics are prescribed unnecessarily. 1, 2 The key differentiator is the presence or absence of acute inflammatory signs and symptoms.
Diagnostic Algorithm
- Assess for acute onset of symptoms (ear pain, irritability, fever, behavioral changes) 1, 2
- Perform pneumatic otoscopy to document MEE and assess TM appearance 2
- Evaluate TM mobility (impaired mobility strongly suggests MEE) 1, 2
- Assess TM appearance:
- Use tympanometry if otoscopic findings are uncertain 1, 2
- Document laterality (unilateral vs bilateral) and severity 1