What does the tympanic membrane appear like on examination in a patient with swimmer's ear?

Tympanic Membrane Appearance in Swimmer's Ear (Acute Otitis Externa)

In swimmer's ear (acute otitis externa), the tympanic membrane typically appears normal with good mobility, though it may show some erythema that can mimic acute otitis media. 1

Distinguishing Features of the Tympanic Membrane in Swimmer's Ear

• The tympanic membrane maintains good mobility when assessed with pneumatic otoscopy, which is a key distinguishing feature from acute otitis media 1
• The membrane may show some erythema that can extend from the ear canal inflammation, potentially causing confusion with acute otitis media 1
• Tympanometry typically shows a normal peaked curve (Type A) in swimmer's ear, unlike the flat tracing (Type B) seen in acute otitis media 1
• The tympanic membrane itself is not the primary site of pathology in swimmer's ear, as the infection primarily affects the external auditory canal 1

Examination Findings to Document in Clinical Notes

• Mobility of tympanic membrane: Should be preserved and normal in uncomplicated swimmer's ear 1
• Color of tympanic membrane: May show some erythema but without the distinct bulging seen in acute otitis media 1
• Integrity of tympanic membrane: Should be intact unless there is a pre-existing perforation or tympanostomy tube 1
• Visibility of tympanic membrane: May be partially obscured by ear canal edema, erythema, or discharge 1, 2

Differentiating from Acute Otitis Media

• In acute otitis media, the tympanic membrane appears distinctly erythematous, bulging, and cloudy with limited or absent mobility 1
• In swimmer's ear, the primary findings are in the ear canal (edema, erythema) rather than the tympanic membrane itself 1, 2
• If pneumatic otoscopy can be performed despite canal edema, it will show normal tympanic membrane mobility in swimmer's ear, unlike the limited mobility in acute otitis media 1
• Tympanometry can help confirm: normal peaked curve (Type A) in swimmer's ear versus flat tracing (Type B) in acute otitis media with effusion 1

Clinical Pearls and Pitfalls

• The hallmark sign of swimmer's ear is tenderness of the tragus or pinna, which is often disproportionately intense compared to the visible changes 1, 2
• Visualization of the tympanic membrane may be difficult due to ear canal edema and discharge, potentially requiring gentle cleaning before adequate assessment 1
• Mistaking swimmer's ear for acute otitis media can lead to unnecessary systemic antibiotic use when topical therapy would be more appropriate 1, 2
• In cases where the diagnosis is uncertain, tympanometry can be used as an adjunct to pneumatic otoscopy to confirm normal tympanic membrane function 1, 3

Documentation Recommendations

• Record the status of the tympanic membrane separately from the ear canal findings 1
• Note whether the tympanic membrane is fully visualized, partially visualized, or not visualized due to canal edema 1
• Document mobility if pneumatic otoscopy was performed 1
• Note any pre-existing conditions such as tympanostomy tubes or perforations that would affect treatment decisions 1