A 14-year-old boy presented to the primary care office with a 4-day history of left ear pain. He denied any history of fever or other associated symptoms. The primary care physician noted a thickened, red, and bulging left tympanic membrane, but the boy had an otherwise normal physical exam. He was diagnosed with acute left otitis media and treated with oral amoxicillin 1,500 mg by mouth twice daily. He returned 4 days later with a complaint of a 1-day history of subjective fever and increasing left ear pain. His oral temperature was 97.0°F in the office. Physical exam revealed mild left postauricular edema and erythema, with no obvious blunting of the retroauricular sulcus. The left cheek was edematous. Exquisite tenderness was noted with manipulation of the left pinna and tragus and on palpation over the left mastoid, cheek, and neck. Otoscopic examination revealed the left auditory canal to be erythematous, very edematous, and tender, with a moderate amount of mucoid drainage. The left tympanic membrane could not be visualized because of obstructive edema of the canal. The left post-auricular node was palpable, mobile, and tender, with no other palpable lymph nodes. The right ear exam was unremarkable, and the remainder of the exam was within normal limits.
Differential diagnoses considered in this case were based on the chief complaint of ear and facial pain. Foreign body was unlikely because of the age of the patient and lack of reported incidence. Dental pathology was ruled out on the basis that oropharyngeal exam was normal, with abnormal exam of the external auditory canal and periauricular structures. Barotrauma was unlikely because the patient had not been flying or deep-water diving. Sinusitis was not diagnosed based on the lack of postnasal drainage, normal nasal exam, and lack of pain with palpation over frontal and maxillary sinuses or dependent head positioning. Otitis media and middle ear effusion could not be definitively ruled out because of the inability to visualize the tympanic membrane.
Based on physical findings, the patient was diagnosed with left otitis externa and possible mastoiditis. He was treated in the office with 1,000 mg of ceftriaxone infused intravenously over 10 minutes and ciprofloxacin-dexamethasone otic drops. The drops were instilled directly into the left auditory canal without an ear wick because the office was out of stock of ear wicks at that time. He was also prescribed amoxicillin/clavulanate potassium 1,000 mg/62.5 mg extended-release tablets, one tablet by mouth every 12 hours for 10 days, and ciprofloxacin-dexamethasone otic solution, four drops to the left ear canal twice daily for 7 days. Instruction was given to the patient regarding reducing risk factors, such as ear trauma and prolonged moisture to the ear canal. The patient was educated on the use of drying agents, such as isopropyl alcohol or the commercially available ear drying aid drops, or a cool hair dryer following swimming or bathing, to prevent future episodes of otitis externa.
For diagnosis, see page 396.
On follow-up the subsequent day, he reported constant and worsening pain in the left ear and face. He was then admitted for inpatient treatment of mastoiditis with intravenous antibiotics, evaluation of the mastoid and facial bones by computed tomography (CT), culture of left ear drainage, and otolaryngological (ENT) consultation.
The CT examination revealed left otitis externa, no abscess, no otitis media, and no mastoid effusion (see Figure 1). On consultation by the ENT, the patient was diagnosed with otitis externa, and an ear wick was placed in the left external auditory canal and instilled with antibiotic otic drops (see Figure 2). The patient was discharged after 2 days of inpatient care. He was prescribed to take amoxicillin 875 mg by mouth twice daily for 5 days, and to instill four drops of ciprofloxacin-hydrocortisone otic solution to the left ear canal twice daily until removal of the wick on postdischarge follow-up. Five days status postinpatient discharge, he presented to the ENT clinic. At that time, his symptoms were greatly improved. He was afebrile, and without otorrhea, pain, or edema. The ear wick was removed revealing an intact and mobile left tympanic membrane.
Figure 1. CT Imaging of Left Otitis Externa Without Abcess and Effusions of the Left Middle Ear and Left Mastoid. The Middle Ear Cavity Is near Complete Opacification. Scattered Inferior Left Mastoid Air Cells Appear with Fluid.
Figure 2. Otitis Externa with Earwick in Place.
Pathophysiology, Presentation, and Treatment of Otitis Externa
Otitis externa, commonly known as “swimmer’s ear,” is an infection of the external auditory canal by a virus, fungus, or, most commonly, bacteria.1,2 One in 10 people are said to have otitis externa, with 80% to 90% of cases being unilateral.2,3 Cases occur most commonly during the summer months.3 Swimmers are at a fivefold greater risk for the infection.2 Noninfectious processes, including allergic or irritant contact dermatitis, atopic dermatitis, psoriasis, seborrheic dermatitis, acne vulgaris, and systemic lupus erythematous, may predispose one to developing otitis externa. Other risk factors include moisture; increased environmental temperatures; exposure to water with high bacterial counts or alkaline pH; and external auditory canal trauma, such as from cotton swabs, earplugs, hearing aids, and fingernails.2–5 These predisposing conditions and contributing factors induce the loss of protective cerumen leading to squamous epithelial edema with obstruction of the glandular secretory ducts. Pruritis of the external canal results and ensuing scratching causes tissue trauma, thus providing a portal of entry for infectious organisms.5 Additionally, the loss of the bacteriostatic and emulsive cerumen, and the altered pH of the normally acidic ear canal, yield an environment conducive to bacterial growth.4 The most common causative organisms of otitis externa are Pseudomonas aeruginosa, Peptostreptococcus, and Staphylococcus aureus, respectively. Infection leads to initiation of the inflammatory process, producing local inflammation and exudate production.5
The patient with otitis externa most commonly presents with otalgia, which may be exquisite and increases with tragal and/or pinnal manipulation. The pain may be severe, although objective signs of inflammation may be of a lesser degree. This imbalance of signs and symptoms results from inflammation of the skin of the ear canal, which is tightly affixed to the perichondial and periosteal tissues. Otalgia is often preceded by pruritis, secondary to the inflammatory process. The patient may also experience conductive hearing loss because of obstructive edema and/or secretions.1 Periauricular and cervical lymphadenopathy, periauricular edema, and painful jaw movement may also be present.1,4
Treatment and Conclusions
Treatment of uncomplicated otitis externa typically consists of topical antibiotics and anti-inflammatory agents.4 These agents are available in combinations, such as ciprofloxacin-hydrocortisone and ciprofloxacin-dexamethasone. The topical solution of choice is typically instilled directly into the infected ear canal until symptoms have been resolved for 3 days. In cases of severe canal edema, the solution may be applied to a cotton wick placed in the external canal to sustain medication at the site.6 Systemic antibiotics may be indicated in such cases as persistent otitis externa, when other local or systemic tissues are affected, or with various other complications.7 The goals of treatment include restoration of the acidic pH, normal flora, cerumen and epithelium, and to alleviate edema and pain.4 When treated properly, the prognosis of uncomplicated otitis externa is usually good.3
- Haddad J. Diseases of the external ear. Behrman RE, Kliegman RM, Jenson HB. In: Nelson Textbook of Pediatrics. 17th ed. Philadelphia, PA: Saunders Elsevier; 2003:2136–2137.
- Moses S. Acute otits externa. In: The Family Practice Notebook: A family medicine resource. 2000. Available at: http://www.fpnotebook.com/ENT/Ear/ActOtsExtrn.htm. Accessed June 22, 2010.
- Schwartz MW, ed. The 5-minute Pediatric Consult. 3rd ed. Philadelphia, PA: Lippincott, Williams, and Williams; 2003.
- La Rosa S. Primary care management of otitis externa. Nurse Pract. 1998;23(6):125–133.
- Oghalai JS. Otitis externa. Presented at The Baylor College of Medicine, Department of Otorhinolaryngology and Communicative Sciences grand rounds. . October 12, 1995. .
- Bojrab DI, Bruderly T, Abdulrazzak Y. Otitis externa. Otolaryngol Clin North Am. 1996;29(5):761–782. Retrieved July 16, 2009, from http://www.bcm.tmc.edu/oto/grand/101295.html.
- Sander RT. Otitis externa: a practical guide to treatment and prevention. Am Fam Physician. 2001;63(5):927–936.
Each month, this department features a discussion of an unusual diagnosis in genetics, radiology, or dermatology. A description and images are presented, followed by the diagnosis and an explanation of how the diagnosis was determined. As always, your comments are welcome. Please e-mail firstname.lastname@example.org.