Ear Pain (Otalgia)

Introduction

Ear pain, or otalgia, is a frequent presenting complaint in Canadian primary care and emergency departments. For the MCCQE1, candidates must demonstrate the ability to differentiate between primary otologic causes and referred pain (secondary otalgia), as the ear shares sensory innervation with several head and neck structures.

Understanding the complex innervation of the ear is crucial for the Medical Expert CanMEDS role. This guide focuses on the high-yield etiology, diagnosis, and management strategies required for MCCQE1 preparation, adhering to Canadian clinical practice guidelines.

MCCQE1 Objectives

According to the Medical Council of Canada, a candidate should be able to:

1. Identify the likely cause of ear pain based on history (e.g., acute onset, chronic, associated symptoms) and physical examination.
2. Differentiate between otogenic (primary) and non-otogenic (referred) causes.
3. Select appropriate investigations for complex or persistent cases.
4. Manage common conditions like Acute Otitis Media (AOM) and Otitis Externa (AOE) according to Canadian stewardship principles.
5. Recognize red flags requiring urgent referral to Otolaryngology (ENT).

Pathophysiology and Anatomy

To master the differential diagnosis of ear pain, one must understand the sensory innervation of the ear. This explains the mechanism of referred otalgia.

Clinical Pearl: A normal ear exam in the setting of severe otalgia demands a thorough examination of the head and neck to rule out malignancy in the aerodigestive tract (shared innervation via CN IX and X).

Clinical Approach

History Taking

Utilize the SOCRATES mnemonic, but focus specifically on:

• Discharge: Otorrhea suggests AOM with perforation or AOE.
• Hearing Loss: Conductive vs. Sensorineural.
• Vertigo/Tinnitus: Suggests inner ear involvement.
• Aggravating Factors: Pain with chewing (TMJ), pain with swallowing (pharyngitis/tonsillitis).
• Risk Factors: Smoking/Alcohol (Head & Neck cancer risk), Swimming (AOE), Daycare attendance (AOM).

Physical Examination

Differential Diagnosis

The differential is best categorized by anatomical location.

Comparison of Common Otologic Conditions

Canadian Guidelines & Management

1. Acute Otitis Media (AOM)

The Canadian Paediatric Society (CPS) emphasizes antimicrobial stewardship. Diagnosis requires:

1. Acute onset of symptoms.
2. Presence of middle ear effusion.
3. Signs of middle ear inflammation (Bulging TM is the most specific sign).

Management Strategy:

Pharmacotherapy:

• First Line: Amoxicillin (80-90 mg/kg/day divided BID). High dose covers resistant S. pneumoniae.
• Penicillin Allergy (Non-Type 1): Cefprozil or Cefuroxime.
• Penicillin Allergy (Type 1): Clarithromycin or Azithromycin.
• Treatment Failure: Amoxicillin-Clavulanate.

2. Acute Otitis Externa (AOE)

• Cleaning: Removal of debris is crucial.
• Topical Antibiotics: Fluoroquinolone drops (e.g., Ciprofloxacin/Dexamethasone) are preferred over aminoglycosides if TM perforation cannot be ruled out (to avoid ototoxicity).
• Oral Antibiotics: Only if cellulitis extends beyond the ear canal or in immunocompromised patients (e.g., diabetes - risk of Malignant Otitis Externa).

3. Choosing Wisely Canada

“Don’t prescribe antibiotics for otitis media with effusion (OME) in children.”

OME usually resolves spontaneously within 3 months. Management involves monitoring for hearing loss and speech delay.

Red Flags (“The Ominous Ear”)

Key Points to Remember for MCCQE1

• Bulging TM is the most specific sign of AOM.
• Tragal tenderness distinguishes AOE from AOM.
• Referred pain is common; always examine the mouth, throat, and neck if the ear exam is normal.
• Unilateral serous otitis media in an adult is nasopharyngeal carcinoma until proven otherwise.
• Ramsey Hunt Syndrome involves the facial nerve (LMN palsy) + vesicles in the ear.
• Malignant Otitis Externa is a skull base osteomyelitis (usually Pseudomonas) seen in elderly diabetics; diagnose with CT/Bone scan.

Study Checklist

• Review cranial nerve innervation of the ear.
• Memorize the “Watchful Waiting” criteria for AOM.
• Practice the SOCRATES history for ear pain.
• Understand the indications for tympanostomy tubes (recurrent AOM or persistent OME with hearing loss).

Sample Question

Scenario

A 58-year-old male presents to the family physician with a 6-week history of right-sided ear pain. He describes the pain as a deep, dull ache. He denies hearing loss, otorrhea, or vertigo. Past medical history is significant for a 30-pack-year smoking history and daily alcohol consumption.

On physical examination:

• Vitals: Temp 37.0°C, BP 135/85, HR 78.
• Right Ear: External canal is clear, tympanic membrane is pearly grey, translucent, and mobile with pneumatic otoscopy. No mastoid tenderness.
• Left Ear: Normal examination.
• Neck: No palpable lymphadenopathy, though the right anterior cervical chain is difficult to assess due to body habitus.

Which one of the following is the most appropriate next step in management?

Options

• A. Prescribe a course of amoxicillin-clavulanate.
• B. Reassure the patient and diagnose Temporomandibular Joint (TMJ) dysfunction.
• C. Order a CT scan of the temporal bones.
• D. Perform flexible nasopharyngoscopy.
• E. Prescribe topical ciprofloxacin/dexamethasone drops.

Explanation

The correct answer is:

• D. Perform flexible nasopharyngoscopy.

Detailed Explanation: This clinical scenario represents a classic “Red Flag” presentation for referred otalgia secondary to a potential head and neck malignancy.

• The Clinical Picture: An older patient with significant risk factors (smoking, alcohol) presents with persistent unilateral otalgia and a normal ear examination.
• Reasoning: The sensory innervation of the ear (CN V, VII, IX, X) overlaps with the pharynx and larynx. Malignancies in the base of tongue, tonsil, hypopharynx, or larynx often refer pain to the ear.
• Why D is correct: Visualization of the upper aerodigestive tract via flexible nasopharyngoscopy (or referral to ENT for the same) is mandatory to rule out cancer.
• Why A & E are wrong: There is no evidence of infection (normal TM, clear canal). Antibiotics are inappropriate stewardship.
• Why B is wrong: While TMJ is a common cause of referred pain, a diagnosis of exclusion should not be made in a high-risk patient without ruling out malignancy first.
• Why C is wrong: CT temporal bone is useful for mastoiditis or middle ear pathology (cholesteatoma), but the ear exam is normal. A CT of the Neck might be indicated later, but direct visualization is the priority.

References

1. Canadian Paediatric Society. (2016). Uncomplicated acute otitis media: Diagnosis and management. Reaffirmed 2022. Available at cps.ca .
2. Choosing Wisely Canada. Otolaryngology - Head and Neck Surgery. Available at choosingwiselycanada.org .
3. Medical Council of Canada. MCCQE Part I Objectives: Ear pain.
4. Toronto Notes. (2023). Otolaryngology Chapter.
5. RxFiles. Anti-Infective Guidelines for Community-acquired Infections.