Surfer’s ear, or exostoses of the external auditory canal, is a slowly progressive disease from benign bone growth as a result of chronic cold water exposure. It is a condition most commonly associated with surfing but seen in anyone repeatedly exposed to cold water such as swimmers, divers, kayakers, and participants of other maritime activities. Usually asymptomatic, external auditory exostoses (EAE) can cause symptoms such as hearing loss, repeated infections, otorrhea, ear fullness, and cerumen impaction. Treatment usually involves medical management but may include surgery if symptoms become severe.
Exostoses develop from prolonged irritation of the external auditory canal, typically with cold seawater. They arise from the bony tympanic ring. Cold water exposure is thought to cause prolonged vasodilatation, and this leads to new bone formation. Only a very thin epithelial layer covers the tympanic ring making this the pathologic area.
In the general population, the prevalence is thought to be 6.3 per 1000 people. EAE is more prevalent in coastal regions where water exposure is common. Therefore, in more at-risk populations such as surfers, the prevalence is between 26% to 73% in studies. The disease is more common in males than in females, most likely due to their higher involvement in water activities. It may be seen in any age, but is more commonly seen in the third and fourth decade of life. Known risk factors include exposure to cold water with an odds ratio of 5.8. Additionally, each year of exposure to cold water increases the risk for development of external auditory exostoses by 12%. Improvements in wetsuit technology has allowed surfers to participate in colder water, which may lead to an increase in prevalence and severity of EAE. Surfer’s ear dates back to prehistoric man and has been used anthropologically to identify cultures with regular aquatic exposure.
It is theorized that the subsequent vasodilation and associated inflammation after cold water exposure over years slowly stimulates bone growth. The area over the tympanic ring is extremely susceptible due to the very thin layer of skin covering the underlying bone. Studies demonstrate that exposure to water colder than 19° C (66° F) leads to the more frequent development of exostoses. Wind chill is also thought to contribute when water is warmer than 19° C. The bone growth typically occurs medially both posteriorly and anteriorly, leading to partial or full occlusion of the external auditory canal. Occlusion leads to a conductive hearing loss and buildup of debris leading to possible otitis externa. EAE may also be the result of pH, chemical, and physical irritants, although less common than cold water exposure. Histologically, the exostoses appear to be concentric layers of subperiosteal bone.
As mentioned, external auditory exostoses is usually an asymptomatic disease, but a patient may present with decreased hearing, ear fullness, chronic otitis externa, otorrhea, or a sensation of water trapped behind the ears. Very rarely does this disease cause pain directly, but maybe a secondary result of otitis externa infection. The history is extremely important in making a diagnosis of this disease. The patient must have repetitive exposure to cold water, usually through water activities such as surfing, kayaking, diving, or swimming. The colder the water, the more severe the disease can be. Some studies suggest a minimum of five years of cold water exposure before significant external auditory exostoses develop while others suggest 10 years.
On physical exam, the practitioner should be able to visualize multi-nodular masses at the tympanic ring with an otoscope. The masses are firm, multiple, and often seen in both external auditory canals. If the exostoses are large enough, they may obscure sight of the tympanic membrane. If hearing loss is present, performing a Rhine and Weber test will demonstrate a conductive hearing loss as opposed to a sensorineural hearing loss. The differential diagnosis for masses in the external auditory canal includes EAE, osteomas, and benign polyps. In general, osteomas are often singular, unilateral and laterally as compared to external exostoses which are multiple, bilateral, and medial. Furthermore, osteomas are commonly pedunculated and occurring at the suture lines. Other potential causes for similar symptoms include otitis media, cerumen impaction, tympanic membrane rupture, and foreign body.
The history and physical exam are typically all that is needed to diagnose external auditory exostoses. The severity of exostoses is graded from 1 to 3 based on the percentage of occlusion of the canal as seen on physical exam. Less than 33% occlusion is mild, 33% to 66% occlusion is moderate, and greater than 66% occlusion is considered severe. To further evaluate, a CT scan of the external auditory canal with less than 1mm thin slices may be performed. On CT scan, the health care practitioner will note broad-based bony overgrowth in the external auditory canal. Usually, the CT scan is reserved for surgical planning and is not necessary for every patient with surfer’s ear.
The treatment mostly consists of medical management involving regular cleaning of the external auditory canal to remove any entrapped debris. If symptoms are severe despite medical management, usually greater than an 80% occlusion, a canaloplasty by an otolaryngologist may be considered. The surgery typically involves general anesthesia with a post-auricular approach by elevating the skin overlying the exostoses and removing the bone with a drill. Another technique is to approach directly from the external auditory canal and use chisels to remove the bony growth. Following surgery, 68% of patients reported an improved life quality while 14% had a surgical complication. Surgery complications include tympanic membrane rupture, delayed healing, canal stenosis, loss of high-frequency hearing, temporomandibular joint dysfunction, and facial nerve paralysis. Due to the rate of complication, surgery is reserved for those who are symptomatic. If symptomatic exostoses exist bilaterally, two canalplasties are performed usually 6 weeks apart. Prevention of surfer’s ear is focused on using silicon earplugs or neoprene hoods to reduce cold water exposure, reducing the risk of development of surfer’s ear.
An interprofessional approach to surfer's ear is recommended.
With more people taking to water-based activities each year, the development of surfer's ear is on the increase in many parts of the country. While the disorder is diagnosed and managed by an otorhinolaryngological (ENT) surgeon, it is important for other healthcare workers to educate the public on how to prevent this condition. While the condition is benign, some symptomatic patients may require surgery. The outcomes in most patients are good, but the rates of surgical complications to relieve the disorder are somewhat high.
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