A 35-year-old woman comes to the office due to left ear pain and itching that began yesterday. The patient is an avid long-distance runner and uses earbuds to listen to music while training. After a long run yesterday, she took out her earbuds and noticed a thick green discharge on the left side. She used cotton-tipped applicators to clean out both ears. This morning, she was unable to insert her left earbud due to significant pain. A similar episode occurred 9 months ago and resolved with appropriate treatment. She takes no medications. Temperature is 37 C (98.6 F), blood pressure is 110/70 mm Hg, and pulse is 70/min. Examination of the left ear causes significant pain. The ear canal is red and swollen, with green drainage that obscures the tympanic membrane. The right ear appears normal. The scalp and hair are normal. Which of the following is the most likely diagnosis?

Question

A 35-year-old woman comes to the office due to left ear pain and itching that began yesterday.  The patient is an avid long-distance runner and uses earbuds to listen to music while training.  After a long run yesterday, she took out her earbuds and noticed a thick green discharge on the left side.  She used cotton-tipped applicators to clean out both ears.  This morning, she was unable to insert her left earbud due to significant pain.  A similar episode occurred 9 months ago and resolved with appropriate treatment.  She takes no medications.  Temperature is 37 C (98.6 F), blood pressure is 110/70 mm Hg, and pulse is 70/min.  Examination of the left ear causes significant pain.  The ear canal is red and swollen, with green drainage that obscures the tympanic membrane.  The right ear appears normal.  The scalp and hair are normal.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec25c8_d399_2a51_bc81_15750d0fcd76_MD0003_00 This patient with rapid-onset ear pain, pruritus, purulent drainage, external auditory canal swelling, and erythema has acute otitis externa (OE). The best-known risk factor for OE, also known as "swimmer's ear," is swimming in outdoor water sources, which alters the ear canal pH, introduces bacteria into the ear canal, and causes skin maceration. However, other conditions that disrupt the skin barrier (eg, trauma from cotton-tipped applicator) or retain moisture in the canal (eg, headphone use while sweating) also can increase the risk. Pseudomonas aeruginosa is the most common pathogen in OE, followed by Staphylococcus aureus. Therefore, empiric treatment regimens should include antipseudomonal antibiotics (eg, fluoroquinolone drops). When the ear canal is significantly swollen, a wick can be used to facilitate medication delivery. Systemic antibiotics are not needed for uncomplicated OE. Patients should also be instructed to keep the ear dry and avoid further trauma. (Choice B) Allergic contact dermatitis is a T cell-mediated delayed-type hypersensitivity reaction. Following sensitization, contact with the allergen causes pruritus and irritation. Rubber and plastic from earbuds can cause allergic contact dermatitis. However, an erythematous, indurated, scaly, plaquelike rash would be expected, drainage would be unusual, and both ears would be affected. (Choice C) Otitis media with effusion may be a cause of ear pain and fullness in adults. The pain is typically less than that of OE, the external canal is clear, and fluid is seen behind the tympanic membrane. (Choice D) Relapsing polychondritis is an inflammatory condition that can affect any cartilage in the body but most commonly affects the cartilaginous portions of the ear (the ear lobule is unaffected because it has no cartilaginous structure). The ear canal is less often affected than the pinna; drainage and itching would be uncommon. Relapsing polychondritis (Choice E) A tympanic membrane perforation can be caused by blunt trauma to the external auditory canal, penetrating trauma to the tympanic membrane, or barotrauma. Although ear pain and drainage can occur at the time of injury (eg, hairpin or cotton-swab insertion), it would be expected to resolve shortly thereafter and would not cause inflammation of the external auditory canal. Educational objective: Acute otitis externa ("swimmer's ear") presents with pain, erythema, and discharge from the ear. It often occurs after disruption of the skin barrier and when conditions cause moisture retention in the external auditory canal. Pseudomonas aeruginosa is the most common pathogen. References: Clinical practice guideline: acute otitis externa. (http://www.ncbi.nlm.nih.gov/pubmed/24491310)

A 35-Year-Old Woman Comes to the Office Due to Left