EM@3AM: Malignant/Necrotizing Otitis Externa

Authors: Russ Burgin (MS4, Bethesda, MD); Rachel Bridwell, MD (EM Attending Physician, WA) // Reviewed by: Sophia Görgens, MD (EM Physician, Northwell, NY); Cassandra Mackey, MD (Assistant Professor of Emergency Medicine, UMass Chan Medical School); Brit Long, MD (@long_brit)

Welcome to EM@3AM, an emDOCs series designed to foster your working knowledge by providing an expedited review of clinical basics. We’ll keep it short, while you keep that EM brain sharp.

A 68-year-old male with a history of poorly controlled diabetes presents to the ED with increasing right-sided ear and facial pain, swelling, and difficulty hearing for two weeks.  He says the pain is worse at night and when he is chewing. Today, he noticed his right face looked swollen and he had an unequal smile.

Triage vital signs include BP 130/75 mm Hg, HR 90 bpm, T 37C, RR 15 breaths per minute, SpO₂ 98% on room air.  A point of care glucose is 148 mg/dL.  On exam, the right side of the patient’s face is notably swollen. The right ear is anteriorly displaced by surrounding edema and is erythematous with malodorous discharge.  There is facial asymmetry that involves the forehead.  Otoscopic exam reveals granulation tissue, as shown below.

What is the diagnosis?

A 67-year-old man with a history of hypertension and diabetes presents to the emergency department with right ear pain for 2 weeks. His vital signs are normal except for a temperature of 38.2°C and a blood pressure of 158/82 mm Hg. On exam, he has a right-sided facial droop that does not spare his forehead. His right ear is exquisitely painful, even with the slight pulling of his auricle. The ear canal is edematous with granulation tissue across the floor of the canal and pale yellow discharge. He has no pain over his mastoid and his physical exam, including a thorough neurologic exam, is otherwise normal. Given this patient’s most likely diagnosis, what is the most appropriate treatment?

A) Immediate surgical debridement

B) Intravenous piperacillin-tazobactam

C) Oral ciprofloxacin and discharge with close follow-up

D) Placement of a ciprofloxacin-instilled ear wick

Answer: B

This patient’s presentation is consistent with necrotizing otitis externa, a rare complication of acute otitis externa. Acute otitis externa is most commonly seen in young children and those who swim. The diagnosis requires the development of otalgia, ear itching, or ear fullness within the last 3 weeks. This must be associated with at least one of the following: diffuse ear canal edema or erythema or tragus or pinna pain with palpation. Fluoroquinolone otic drops are the mainstay of treatment for uncomplicated cases. If the ear canal is too edematous for drops to reach the deeper portions, an ear wick instilled with ciprofloxacin or ofloxacin should be used. If an ear wick is placed, close follow-up with an otolaryngologist should be arranged in the next 2–3 days.

For immunosuppressed patients (those with diabetes), systemic fluoroquinolones are recommended. The majority of patients improve with these treatments. However, older patients, those with diabetes, and immunocompromised patients with acute otitis externa may progress to the necrotizing form. This presents with similar symptoms to acute otitis externa with the addition of granulation tissue across the floor of the ear canal, purulent discharge, periauricular pain and swelling, headache, or any combination of these. Notably, as the infection spreads toward the base of the skull, cranial nerve palsies may result, with facial nerve involvement being the most common. Treatment depends on the severity of the case and risk factors for worsening infection (e.g., diabetes, immunosuppression, older patient). This patient has diabetes and systemic signs of illness (i.e., fever). He should be treated with intravenous antibiotics with pseudomonal coverage and admission. While these patients may need surgical debridement if the infection does not improve, antibiotics should not be delayed. Healthy individuals with mild infection and without systemic signs of illness may be discharged home with oral ciprofloxacin. However, given the severity of this infection and the potential for meningeal spread, there should remain a low threshold to admit these patients to ensure adequate improvement in the infection.

Immediate surgical debridement (A) was previously the mainstay of care in necrotizing external otitis, a rare complication of acute otitis externa. However, the bioavailability of antipseudomonal antibiotics has improved outcomes, limiting surgery as a confirmatory diagnostic procedure and as needed for granulation tissue removal.

Oral ciprofloxacin and discharge with close follow-up (C) is not appropriate in this patient with diabetes, signs of systemic illness, and evidence of peripheral nerve involvement. Outpatient treatment is reserved for healthy patients with early infection and adequate follow-up.

Placement of a ciprofloxacin-instilled ear wick (D) is a common treatment for acute otitis externa, as noted above, but treatment of necrotizing external otitis requires systemic ciprofloxacin.

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