Contents
External auditory exostoses (EAE), also known as “Surfer’s ear” is a slowly progressive disease from benign bone growth as a result of chronic cold-water exposure.
Etiology
Cold water exposure:
Exostoses develop from prolonged irritation of the external auditory canal, typically with repeated cold seawater exposure. This exposure stimulates new bone formation at the tympanic ring within the external auditory canal. The prevalence and severity is directly proportional to the cumulative duration and frequency of cold water exposure
- Surfing “swimmer’s ear” (M/C)
- Other causes of cold water exposure: Swimmers, divers, kayakers, and participants of other maritime activities
Presentation
Patient usually has multiple years of repetitive exposure to cold water, usually through water activities such as surfing, kayaking, diving, or swimming. Some studies suggest a minimum of five years of cold water exposure before significant external auditory exostoses develop while others suggest 10 years.
Asymptomatic presentation:
EAE is usually asymptomatic and benign
Symptomatic cases:
EAE is usually not the primary cause of a patient complaint, but can be a risk factor for the underlying etiology of the patient’s presentation. For example, very rarely does this disease cause pain directly, but pain may be a secondary result of an otitis externa infection incited by external auditory exostoses.
- Decreased hearing (conductive hearing loss)
- Chronic/recurrent otitis externa
- Otalgia
- Otorrhea
- Cerumen impaction and water trapping
Diagnosis
Direct otoscopic examination:
Carefully perform an ear lavage to better visualize the ear structures.
- Multi-nodular masses at tympanic ring (size proportional to degree of symptoms) in bilateral ears
- Cerumen impaction (as a result of entrapment behind/within exostoses)
Tuning fork test:
Demonstrate a conductive hearing loss as opposed to a sensorineural hearing loss
- Rhine test
- Weber test
CT scan:
Usually, the CT scan is reserved for surgical planning and is not necessary for every patient with EAE. MRI is also occasionally utilized for surgical planning.
- Broad-based bony overgrowth in the external auditory canal
Management
Early detection and prevention of progression of surfer’s ear is paramount as once the exostoses are formed, they are irreversible unless surgical intervention is performed.
Preventive measures:
EAE is a progressive disease, however the risk of progression can be mitigated with consistent preventive measures by reduce auditory canal to colder elements
- Silicon earplugs
- Neoprene hoods
Medical management:
Help prevent the propagation of complications such as recurrent otitis externa, tympanic membrane rupture, and conductive hearing loss.
- Regular cleaning of the external auditory canal to remove any entrapped debris
Surgical management:
If there is greater than 80% occlusion and symptoms are severe and persistent despite medical management, surgical intervention is required
- Canalplasty: Post-auricular approach under general anesthesia by elevating the skin overlying the exostoses and removing the bone with a drill
- Alternative approach: Direct external auditory canal approach and use chisels to remove the bony growth
Surgery complications:
Due to the rate of complication, surgery is reserved for those who are symptomatic and refractive to medical management. If the patient requires bilateral surgery, two canalplasties are performed about 6 weeks apart
- Tympanic membrane rupture
- Delayed healing
- Canal stenosis
- Loss of high-frequency hearing
- Temporomandibular joint dysfunction
- Facial nerve paralysis