Injected Tympanic Membrane: Safety and Clinical Applications
Direct Answer
Intratympanic steroid injection through the tympanic membrane is a safe and established treatment for specific inner ear conditions, particularly sudden sensorineural hearing loss and Ménière's disease, with low complication rates when performed correctly. 1, 2
Primary Indications for Intratympanic Injection
Sudden Sensorineural Hearing Loss
Intratympanic steroids serve as both initial therapy (when systemic steroids are contraindicated) and salvage therapy for sudden sensorineural hearing loss. 2
Initial therapy: Patients with contraindications to systemic steroids—including insulin-dependent or poorly controlled diabetes, labile hypertension, glaucoma, active tuberculosis, peptic ulcer disease, or prior psychiatric reactions to corticosteroids—should be offered intratympanic steroid therapy as first-line treatment 2
Salvage therapy: For incomplete recovery at 2-6 weeks after initial systemic treatment, intratympanic steroids provide a second-line option with typical protocols of 4-6 injections over 2 weeks 2
Dosing protocols: Use dexamethasone 24 mg/mL (compounded) or 10 mg/mL (stock), or methylprednisolone 40 mg/mL or 30 mg/mL, injecting 0.4-0.8 mL into the middle ear space 2
Ménière's Disease
Intratympanic steroid therapy provides vertigo control with lower risk of hearing loss compared to intratympanic gentamicin. 3
Complete vertigo control (class A) occurs in 31-90% of subjects with intratympanic steroids versus 70-87% with gentamicin 3
Treatment-associated hearing loss risk is substantially lower: 0-8% with steroids versus 12.5-15.4% with gentamicin 3
Dosing: Inject 0.4-0.8 mL of dexamethasone (4-24 mg/mL) or methylprednisolone (30-62.5 mg/mL) into middle ear space, from once only or up to 3-4 sessions every 3-7 days depending on clinical response 3
Safety Profile and Complications
Common Minor Complications
The frequency of adverse events is low, with most complications being transient and self-limited. 4, 5
Transient dizziness/vertigo: More common with posterior quadrant injections (posterior-inferior Q3 and posterior-superior Q4) compared to anterior quadrants 4
Pain and otalgia: Occurs in approximately 16% of patients, typically resolving within 0.5-2 hours without treatment 5
Tongue numbness: More likely with anterior-superior (Q1) and posterior-superior (Q4) injections 4
Transient tinnitus: Reported but generally self-limited 4
Persistent Tympanic Membrane Perforation
The principal risk of intratympanic steroid therapy is persistent tympanic membrane perforation, though this remains rare. 1
The American Academy of Otolaryngology-Head and Neck Surgery notes this complication is generally rare and often resolves spontaneously or with paper patch myringoplasty 1
Perforation risk with proper technique is only 1.0-1.4% in large series 6
Critical caveat: Significantly increased perforation rates occur when steroids are administered through myringotomy tubes rather than direct injection—one study reported 11 perforations in patients using home-based dexamethasone instillation through tubes 7
Serious Complications
Serious adverse events are extremely rare but include aggravation of hearing loss. 5
One case of hearing loss aggravation after intratympanic injection was reported in a series of 38 patients 5
No infections occurred in the same series when proper technique was used 5
Optimal Injection Technique
Inject into the anterior-inferior quadrant (Q2) to minimize complications. 4
Q2 injection avoids the higher risk of tongue numbness associated with Q1 and Q4 4
Q2 injection avoids the higher risk of post-injection vertigo associated with Q3 and Q4 (P = 0.0113) 4
Patient should maintain head in otologic position (affected ear up) for 15-30 minutes after injection 2
Frequency: Up to 4 injections over a 2-week period for sudden sensorineural hearing loss 2
Advantages Over Systemic Administration
Intratympanic delivery provides superior pharmacokinetics with fewer systemic side effects. 1, 8
Higher inner ear steroid concentrations compared to systemic administration 1
Avoids systemic side effects of oral steroids, making it suitable for patients with diabetes, cataracts, myasthenia gravis, and glaucoma 1
Targeted drug delivery allows higher therapeutic doses while minimizing systemic effects 8
Contraindications and Precautions
When NOT to Use Intratympanic Steroids
Do not use intratympanic or any steroids for otitis media with effusion due to preponderance of harm over benefit. 1
Pre-existing Perforation Management
When a perforation is present or suspected, prescribe non-ototoxic topical preparations to avoid potential hearing damage. 1
If steroids are deemed necessary in patients with perforations, consider systemic administration rather than topical or intratympanic routes 1
Tympanometry can help establish the presence of an intact membrane when the tympanic membrane cannot be fully visualized due to swelling 1
Monitoring Requirements
Essential audiometric assessments ensure appropriate treatment response and guide therapy adjustments. 2
Baseline audiometry within 14 days of symptom onset to confirm diagnosis 2
Mid-treatment interval audiograms can be considered between intratympanic injections to guide early termination if hearing resolves 2
Post-treatment audiogram at completion of treatment course 2
Final assessment: repeat audiometry at 6 months post-treatment regardless of perceived recovery 2
Monitor for adverse effects such as hyperglycemia and hypertension in susceptible patients 2
Clinical Pitfalls to Avoid
Avoid myringotomy tube placement specifically for home-based intratympanic steroid administration, as this significantly increases perforation risk. 7
Do not irrigate or perform pneumatic otoscopy when perforation is suspected. 9
Avoid posterior quadrant injections when possible to minimize vertigo risk. 4