A 5-year-old boy is brought to the clinic due to persistent ear drainage. The patient first developed drainage from his right ear 6 months ago. When the drainage did not improve with antibiotics, he was diagnosed with a cholesteatoma, which was removed. After surgery, the patient's symptoms improved but recurred following an episode of acute otitis media. Over the past 2 months, he has been treated with several oral antibiotics with only transient improvement. Examination shows copious, foul-smelling, purulent drainage from the right ear canal. The ear is suctioned, revealing a normal-appearing external canal. The tympanic membrane is heavily scarred with a large perforation and no cholesteatoma. Which of the following organisms is the most likely cause of this patient's infection?

Question

A 5-year-old boy is brought to the clinic due to persistent ear drainage.  The patient first developed drainage from his right ear 6 months ago.  When the drainage did not improve with antibiotics, he was diagnosed with a cholesteatoma, which was removed.  After surgery, the patient's symptoms improved but recurred following an episode of acute otitis media.  Over the past 2 months, he has been treated with several oral antibiotics with only transient improvement.  Examination shows copious, foul-smelling, purulent drainage from the right ear canal.  The ear is suctioned, revealing a normal-appearing external canal.  The tympanic membrane is heavily scarred with a large perforation and no cholesteatoma.  Which of the following organisms is the most likely cause of this patient's infection?

Quizplus · Accepted Answer

11ec25c8_d652_f3cd_bc81_b9b9d3177df2_MD0003_00 This patient has chronic, purulent ear drainage with a tympanic membrane (TM) perforation, findings consistent with chronic suppurative otitis media (CSOM). CSOM is most common in young children due to an increased incidence of acute otitis media, a major risk factor for CSOM. Conditions that lead to negative middle ear pressure (eg, dysfunction of the eustachian tubes, cholesteatoma) also contribute to the pathogenesis because the TM can weaken over time with sustained pressure, increasing the risk of perforation, as seen in this patient. Bacteria from the external auditory canal are then introduced into the middle ear and can lead to chronic inflammation and infection, most commonly with Staphylococcus aureus and/or Pseudomonas aeruginosa. acute otitis media cholesteatoma Presentation includes chronic (>6 weeks) purulent otorrhea with TM perforation. The external ear canal typically appears normal, and ear pain is uncommon. Diagnosis is clinical, and management is ototopical fluoroquinolone drops. CSOM does not typically respond to oral antibiotics, as seen in this patient, because the middle ear is poorly vascularized due to chronic inflammation and scarring. Of note, cholesteatoma can also cause chronic ear drainage, as seen in this patient's history, and should be considered when the condition does not respond to topical therapy for presumed CSOM. TM perforation (Choice A) Bordetella pertussis is not associated with CSOM; it can cause chronic cough, not otorrhea. (Choices B, C, D, E, and G) Fungal causes of CSOM can include Aspergillus and Candida albicans; however, bacterial infection is much more common. Corynebacterium diphtheriae, Escherichia coli, Mycobacterium species, and coagulase-negative staphylococcal species (eg, Staphylococcus epidermidis) are uncommon bacterial causes of CSOM. Educational objective: Chronic suppurative otitis media is often preceded by an episode of acute otitis media and is defined as chronic (>6 weeks), purulent otorrhea with tympanic membrane perforation. Treatment is an ototopical fluoroquinolone to target the most common pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. References: Chronic suppurative otitis. (http://www.ncbi.nlm.nih.gov/pubmed/32119479) Bacteriological profile and antimicrobial susceptibility pattern in chronic suppurative otitis media: a 1-year cross-sectional study. (http://www.ncbi.nlm.nih.gov/pubmed/31750155)

A 5-Year-Old Boy Is Brought to the Clinic Due to Persistent