What could cause acute fluctuating hearing loss in a 69‑year‑old woman after recent pneumonia treated with doxycycline and systemic corticosteroids (prednisone)?

Acute Fluctuating Hearing Loss After Pneumonia and Treatment

This patient's fluctuating hearing loss most likely represents either sudden sensorineural hearing loss (SSNHL) that is partially recovering, Ménière's disease, or autoimmune inner ear disease—all of which require urgent audiometric evaluation and consideration for corticosteroid therapy if not already adequately treated. 1

Critical Differential Diagnosis

Most Likely: Sudden Sensorineural Hearing Loss (SSNHL)

• Fluctuating hearing is atypical for classic SSNHL and should raise suspicion for alternative diagnoses including Ménière's disease, autoimmune inner ear disease, Cogan syndrome, or hyperviscosity syndromes 1
• The American Academy of Otolaryngology-Head and Neck Surgery emphasizes that most cases of SSNHL are not preceded by fluctuating hearing 1
• However, partial recovery from SSNHL can create fluctuating symptoms as the auditory system recovers 2

Ménière's Disease

• Definite Ménière's requires: two or more spontaneous vertigo attacks lasting 20 minutes to 12 hours, audiometrically documented low-to-mid frequency SNHL, and fluctuating aural symptoms (hearing loss, tinnitus, or ear fullness) 1
• The fluctuating nature of this patient's hearing loss is highly characteristic of Ménière's disease 1
• Vertigo history is critical to distinguish this diagnosis 1

Autoimmune Inner Ear Disease

• Presents with fluctuating bilateral hearing loss that is steroid-responsive, though unilateral presentation can occur 1
• May present with vertigo in some cases 1
• The recent systemic steroid exposure for pneumonia may have partially treated underlying autoimmune disease 1

Infection-Related Causes

• Mycoplasma pneumoniae can cause sudden unilateral deafness and the patient was treated for pneumonia with doxycycline (appropriate coverage) 3
• Viral infections are the most common presumed cause of idiopathic SSNHL 4, 5
• COVID-19 has been associated with SSNHL, though this patient had bacterial pneumonia 4

Medication-Related Ototoxicity

• Doxycycline is not typically ototoxic, unlike aminoglycosides or loop diuretics 6
• The combination of aminoglycosides with furosemide significantly increases ototoxicity risk, but this patient received doxycycline 6
• Systemic corticosteroids themselves can cause blurred vision and other side effects but not typically fluctuating hearing loss 1

Immediate Diagnostic Workup Required

Essential Testing

• Formal audiometry must be performed immediately to document the type and degree of hearing loss (conductive vs. sensorineural, frequency pattern, severity) 1
• Tympanometry to exclude middle ear effusion or Eustachian tube dysfunction 2
• Weber and Rinne tuning fork tests can provide bedside differentiation between conductive and sensorineural loss 1

History Elements to Clarify

• Presence, timing, and duration of vertigo episodes (critical for Ménière's diagnosis) 1
• Tinnitus characteristics and whether it fluctuates with hearing 1
• Ear fullness or pressure sensation 1
• Prior episodes of hearing loss or vertigo 1
• Bilateral vs. unilateral symptoms 1
• Timing relative to pneumonia onset and treatment 4, 3

Additional Workup if SSNHL Confirmed

• MRI with gadolinium dedicated to internal auditory canals to exclude vestibular schwannoma, stroke, or structural lesions 5
• Consider autoimmune workup if bilateral or recurrent 1
• Mycoplasma serology if pneumonia was atypical 3

Treatment Recommendations

If SSNHL is Confirmed and Within 14 Days of Onset

• Initiate oral prednisone 1 mg/kg/day (maximum 60 mg/day) for 7-14 days followed by taper, even if patient recently completed steroids for pneumonia 1, 7
• Treatment must begin immediately, ideally within 14 days of symptom onset, though benefit has been reported up to 6 weeks 1
• The greatest spontaneous improvement occurs in the first 2 weeks 1, 2

Alternative: Intratympanic Steroids

• If systemic steroids are contraindicated or patient cannot tolerate them, offer intratympanic dexamethasone 24 mg/mL or methylprednisolone 40 mg/mL 1, 7
• Inject 0.4-0.8 mL into middle ear space, up to 4 injections over 2 weeks 1
• Patient maintains head in otologic position (affected ear up) for 15-30 minutes 1

If Beyond 2 Weeks or Incomplete Recovery

• Consider intratympanic steroids as salvage therapy if hearing recovery is incomplete at 2-6 weeks after initial treatment 1, 7
• One-third to two-thirds of patients experience spontaneous recovery within the first 2 weeks 7

Critical Pitfalls to Avoid

Delayed Diagnosis

• Do not wait to see if symptoms resolve spontaneously—immediate audiometry and treatment within 14 days is essential 1, 7
• Maximum improvement occurs within 2 weeks of onset, making early intervention critical 5

Misattributing to Recent Illness or Medications

• Do not assume the hearing loss is simply a side effect of doxycycline or steroids without formal audiometric confirmation 6
• While the pneumonia or its treatment may be temporally related, SSNHL requires specific urgent management 4, 3

Missing Bilateral Involvement

• Bilateral sudden hearing loss is rare and suggests specific causes including autoimmune disease, meningitis, ototoxic medications, or systemic infections 1, 7
• Requires more aggressive workup and bilateral treatment 7

Overlooking Ménière's Disease

• If vertigo episodes are present with fluctuating hearing, tinnitus, and ear fullness, this is Ménière's disease until proven otherwise 1
• Management differs significantly from SSNHL 1

Prognosis and Follow-up

Expected Recovery

• Prognosis is best when patients are seen early, begin recovery within 2 weeks, and have mild hearing loss (<90 dB) with upward-sloping audiograms 5
• Greater than 90 dB hearing loss, flat or downsloping audiogram, advanced age, and presence of vertigo are adverse prognostic factors 5

Monitoring Schedule

• Audiogram at completion of treatment course and at delayed intervals (1.5-3 months) 1, 2
• Continued hearing improvement can occur up to 3 months after treatment initiation 2
• Tympanic membrane inspection if intratympanic steroids were used 1, 2