What is the differential diagnosis (DDX) and management for left ear pain with preauricular swelling and tenderness, inability to visualize the tympanic membrane (TM) due to ear wax, and worsening pain at night?

Differential Diagnosis and Management of Left Ear Pain with Preauricular Swelling

Immediate Priority: Remove Cerumen to Visualize the Tympanic Membrane

You must remove the obstructing cerumen immediately to establish an accurate diagnosis, as visualization of the tympanic membrane is essential to differentiate between acute otitis media, otitis externa, and other serious conditions. 1

Cerumen Removal Technique

• Use cerumenolytic agents, irrigation, or manual removal with instrumentation to clear the ear canal and enable proper otoscopic examination 1
• Assess for contraindications before removal: anticoagulant therapy, immunocompromised state, diabetes mellitus, prior head/neck radiation, ear canal stenosis, or suspected tympanic membrane perforation 1
• If initial removal attempts fail, refer to a specialist with appropriate equipment and training 1

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Differential Diagnosis

Most Likely: Acute Otitis Media (AOM)

The combination of ear pain worsening at night with preauricular swelling strongly suggests AOM with possible complications 1, 2

• Bulging tympanic membrane is the most consistent sign of AOM and the most useful feature for diagnosis (96% bacterial isolation rate when present) 1
• Cloudy or opaque tympanic membrane is highly predictive of middle ear effusion (95.7% positive predictive value) 1
• Intense erythema of the tympanic membrane with recent onset (<48 hours) of ear pain meets diagnostic criteria 1
• Preauricular swelling may indicate preauricular lymphadenopathy or early mastoiditis complication 1
• Night pain is characteristic of increased middle ear pressure from effusion 3

Alternative: Acute Otitis Externa (AOE)

AOE is less likely given preauricular swelling, but must be excluded once the canal is visualized 1, 4, 5

• Tragal tenderness is pathognomonic for AOE - test by pressing on the tragus or pulling the pinna 1, 4, 6, 5
• Look for ear canal edema, erythema, and debris on otoscopy 1, 4, 5
• Preauricular swelling is uncommon in uncomplicated AOE but can occur with severe cases 1
• Pain typically has sudden onset and worsens with jaw movement 5

Serious Consideration: Mastoiditis

Preauricular/postauricular swelling with ear pain requires evaluation for acute mastoiditis, a potentially life-threatening complication 1

• Assess for postauricular erythema, swelling, and tenderness over the mastoid bone 1
• Look for displacement of the pinna anteriorly and inferiorly 1
• Fever, systemic symptoms, or neurological signs mandate immediate imaging and specialist referral 1

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Management Algorithm

Step 1: Remove Cerumen and Perform Complete Otoscopic Examination

• Apply cerumenolytic agents for 15 minutes to 5 days, then irrigate or manually remove 1, 7
• Document tympanic membrane color, position (bulging vs. retracted), opacity, and mobility with pneumatic otoscopy 1
• Assess for perforation or drainage 1

Step 2: If AOM Diagnosed (Bulging TM + Acute Symptoms)

Immediate pain management is the priority - analgesics provide relief within 24 hours while antibiotics do not provide symptomatic relief in the first 24 hours 3, 6

• Prescribe acetaminophen or NSAIDs immediately at fixed intervals, not PRN 3, 6
• For moderate-to-severe pain, use combination acetaminophen/ibuprofen with opioid (48-72 hour supply only) 6
• Antibiotic decision based on severity:
  • Severe AOM (temperature ≥39°C, moderate-to-severe otalgia >48 hours): prescribe antibiotics immediately 1
  • Non-severe AOM: observation with close follow-up is an option with shared decision-making 3
• Reassess in 48-72 hours - 30% of children have persistent pain even after 3-7 days of appropriate treatment 3

Step 3: If AOE Diagnosed (Tragal Tenderness + Canal Inflammation)

Prescribe topical antibiotics covering Pseudomonas aeruginosa and Staphylococcus aureus as first-line therapy 1, 4, 3, 6

• Do NOT prescribe systemic antibiotics for uncomplicated AOE - this represents inappropriate antibiotic use 1, 4, 3, 6
• Use topical antibiotic/steroid combination drops (e.g., ciprofloxacin/dexamethasone) 4
• If tympanic membrane perforation suspected, use only non-ototoxic preparations 6
• Provide adequate analgesia with NSAIDs or acetaminophen 6, 5
• Expect improvement within 48-72 hours; reassess if no improvement 4, 5

Step 4: If Preauricular Swelling Persists or Worsens

Obtain CT temporal bone without contrast to evaluate for mastoiditis or other complications 1

• Look for mastoid air cell opacification, bony erosion, or abscess formation 1
• Refer immediately to otolaryngology if imaging shows complications 1

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Critical Clinical Pitfalls

Failure to Remove Cerumen Before Treatment

Treating ear pain without visualizing the tympanic membrane leads to misdiagnosis and inappropriate therapy 1

• Cerumen impaction itself can cause ear pain, but you cannot exclude serious pathology without visualization 1
• Document resolution of cerumen impaction and reassess for alternative diagnoses if symptoms persist 1

Inadequate Initial Analgesia

Failing to provide adequate pain relief in the first 24 hours is a critical error, as antibiotics provide no symptomatic benefit during this period 3, 6

• Pain management should begin immediately at appropriate starting doses 6
• Fixed-interval dosing is superior to PRN dosing for moderate-to-severe pain 6

Prescribing Systemic Antibiotics for Uncomplicated AOE

This represents inappropriate antibiotic use and increases resistance without improving outcomes 1, 4, 3, 6

• Topical therapy is superior to systemic antibiotics for uncomplicated AOE 1, 4
• Reserve systemic antibiotics for complications or immunocompromised patients 1

Missing Mastoiditis or Malignancy

Preauricular swelling with persistent symptoms despite appropriate therapy requires imaging and specialist evaluation 1

• In adults >50 years with tobacco/alcohol use or diabetes, persistent otalgia with normal ear exam may indicate upper aerodigestive tract malignancy 3
• Immunocompromised or diabetic patients are at risk for necrotizing otitis externa, which requires aggressive management 6