What is the most common cause (MCC) of ear pain in adults?

Most Common Cause of Ear Pain in Adults

Otitis externa (inflammation of the external ear canal) is the most common cause of ear pain in adults, with a lifetime incidence of approximately 10%. 1

Epidemiology and Etiology

• Otitis externa affects adults more commonly than children 1
• The primary causative organisms are bacterial, with Pseudomonas aeruginosa and Staphylococcus aureus accounting for 98% of cases in North America 2, 3
• Fungal infections (Aspergillus or Candida species) are less common causes of otitis externa 1, 2
• "Swimmer's ear" is a common variant due to conversion of the normal acidic environment of the ear canal to alkaline from water exposure 1, 2

Clinical Presentation

• Characteristic symptoms include otalgia (ear pain), tenderness, fever, and ear discharge 1, 3
• Pain can be intense and severe because the highly sensitive periosteum of the underlying bone is in close proximity to the ear canal skin 1
• Tenderness on movement of the pinna or tragus is the classic finding 3
• Erythema and swelling of the canal with variable discharge are common physical findings 4

Other Common Causes of Ear Pain in Adults

Primary Otalgia (Pain Originating from the Ear)

• Furunculosis (infected hair follicle in the outer third of ear canal) - presents with localized tenderness, focal swelling, and pustular lesions 1
• Acute otitis media - characterized by erythematous, bulging, and cloudy tympanic membrane 5
• Viral infections (herpes zoster oticus/Ramsay Hunt syndrome) - presents with vesicles on the external ear canal and posterior auricle 1

Secondary Otalgia (Pain Referred to the Ear)

• Temporomandibular joint (TMJ) syndrome - most common cause of referred ear pain in adults 1, 6
• Dental pathologies (caries, impacted molars) 1, 6
• Tonsillitis, peritonsillar abscesses 1
• Upper aerodigestive tract malignancies - particularly concerning in older patients with tobacco and alcohol use history 1, 6

Differential Diagnosis

• Contact dermatitis (irritant or allergic) - can mimic or coexist with otitis externa 1
• Seborrheic dermatitis - presents with greasy yellowish scaling and itching 1
• Cholesteatoma - typically painless with tympanic membrane abnormalities 1
• Dermatologic conditions (psoriasis, discoid lupus erythematosus) 1

Management Considerations

• Pain relief is an essential component of managing otitis externa 1
• Thorough cleansing of the ear canal is essential for diagnosis and treatment 4
• Topical antibiotics deliver antimicrobial concentrations 100-1000 times higher than systemic therapy 2
• Oral antibiotics should be reserved for cases with extension beyond the ear canal or in immunocompromised patients 2, 3

Prevention

• Avoiding excessive moisture and trauma to the ear canal, which impair the canal's natural defenses 4
• Acidification with topical solutions (like 2% acetic acid) after moisture exposure 4
• Drying ears thoroughly after swimming or bathing 4, 3

Clinical Pitfalls

• Failure to recognize referred pain from non-ear sources can lead to missed diagnoses, particularly concerning for malignancies in adults with risk factors 1, 6
• Confusing otitis externa (external ear) with otitis media (middle ear) can lead to inappropriate treatment 2
• Persistent symptoms despite appropriate treatment should prompt consideration of resistant organisms, fungal infection, or underlying conditions 1
• Necrotizing otitis externa is a serious complication in immunocompromised patients or those with diabetes that requires prompt recognition and treatment 1