Currently, most researchers agree that the environment (especially water temperature, but also atmospheric temperature and wind action) plays a pivotal role in the development of this trait.

Aural exostoses are typically firm, sessile, multinodular bony masses usually arise from the tympanic ring of the bony portion  of the external auditory canal.

Although most of the cases are asymptomatic, patients with more severe exostoses have recurrent episodes of external otitis and related conductive hearing loss.

In the great majority of these cases, a medical treatment (aspiration and antibiotic drops) resolves the symptoms.

Patients with more severe canal stenosis, resistant to medical treatment, are candidates for surgical removal of the exostoses.

Visit: Ear Pathology Online ; Benign Fibro-Osseous Lesion of the External Ear ; Osteoma of the Ear (external auditory canal and middle ear) ;

Auditory exostoses as an aquatic activity marker: a comparison of coastal and inland skeletal remains from tropical and subtropical regions of Brazil.Am J Phys Anthropol. 2007 Apr;132(4):558-67.

Auditory exostoses are bone masses located in the external auditory canal. Currently, most researchers agree that the environment (especially water temperature, but also atmospheric temperature and wind action) plays a pivotal role in the development of this trait. This article discusses whether the presence of auditory exostoses can be used as an aquatic activity marker in bioarchaeological studies, especially in groups that inhabited tropical and subtropical regions. We analyzed 676 skeletons (5,000 years BP to historical times) from 27 coastal and inland native Brazilian groups. Very low frequencies of auditory exostoses were found in the inland groups (0.00-0.03), but the expected high frequency of auditory exostoses in the coastal groups was not always observed (0.00-0.56). These differences might be explained by the combination of water and atmospheric temperatures in conjunction with wind effects. In areas with mild atmospheric temperatures and wind chill factors, the coastal populations analyzed do not show high frequencies of auditory exostoses. However, high frequencies of auditory exostoses develop where cold atmospheric temperatures are further lowered by strong wind chill. Therefore, the association between aquatic activities, low atmospheric temperature, and wind chill is strongly correlated with the presence of auditory exostoses, but where these environmental factors are mild, the frequencies of auditory exostoses are not necessarily high. Concluding, auditory exostoses should be cautiously used as a marker of aquatic activity in bioarchaeological studies in tropical and subtropical regions, since these activities do not always result in the presence of this trait.

Exostosis of the internal auditory canal in a patient with myotonic dystrophy. Laryngorhinootologie. 2006 Oct;85(10):755-9.

A 53-year-old patient with myotonic dystrophy presented to our clinic with progressive bilateral hearing loss. The ENT status and particularly the otological examination were without pathological signs. Pure tone audiograms showed a bilateral moderate to severe sensorineural hearing loss. Routinely performed computed tomography of the temporal bones revealed the rare picture of exostosis of the internal auditory canals and the medial surface of the petrous bones. To our knowledge, this is the first report describing exostosis of the internal auditory canal in a patient with myotonic dystrophy, although at present it remains unclear in how far there is a causal connection between these two pathologies.

Exostoses of the external auditory canal: a long-term follow-up study of surgical treatment.Clin Otolaryngol Allied Sci. 2004 Dec;29(6):588-94.

To determine the postoperative incidence, extent and recurrence rate of exostoses of the external auditory canal in a cohort of patients involved in different water sports. A cross-sectional study of 31 patients (46 ears), with exostoses treated by surgery in the Royal Cornwall Hospital between 1980 and 1999. A questionnaire was used to obtain information about the type of water exposure pre- and postoperatively. The extent of recurrent stenosis was assessed. The mean postoperative time interval was 10 years (sd = 4.5 years). The degree of stenosis was assessed as: minimal (<30%) in 42.6%, moderate (30-60%) in 31% and severe (>60%) in 25% of ears. The Cox regression model was used to identify factors associated with a reduction in the recurrence rate of stenosis. The use of ear plugs was highly significant (P = 0.015), as was the age of the patient at the time of operation (P = 0.004), i.e. the older the patient, the faster recurrent disease developed. There was no evidence to show that either the type or seasonal pattern of water sport activity influenced recurrence of the disease postoperatively, although preoperatively, the stenosis was more marked in association with surfing and sailing. Exostoses developed faster preoperatively in those who were in the water all year round rather than just the summer months. Of five patients who stopped water sport activity completely after surgery, four of them developed significant recurrent exostoses (>50% stenosis).

Surfer's ear: external auditory exostoses are more prevalent in cold water surfers.Otolaryngol Head Neck Surg. 2002 May;126(5):499-504.

OBJECTIVE: The study goal was to demonstrate the prevalence and severity of external auditory exostoses (EAEs) in a population of surfers and to examine the relationship between these lesions and the length of time surfed as well as water temperature in which the swimmers surfed. It was hypothesized that subjects who predominantly surfed in colder waters had more frequent and more severe exostoses. METHODS: Two hundred two avid surfers (91% male and 9% female, median age 17 years) were included in the study. EAEs were graded based on the extent of external auditory canal patency; grades of normal (100% patency), mild (66% to 99% patency), and moderate-severe (<66% patency) were assigned. Otoscopic findings were correlated with data collected via questionnaires that detailed surfing habits. RESULTS: There was a 38% overall prevalence of EAEs, with 69% of lesions graded as mild and 31% graded as moderate-severe. Professional surfers (odds ratio 3.8) and those subjects who surfed predominantly in colder waters (odds ratio 5.8) were found to be at a significantly increased risk for the development of EAEs. The number of years surfed was also found to be significant, increasing one's risk for developing an exostosis by 12% per year and for developing more severe lesions by 10% per year. Individuals who had moderate-severe EAEs were significantly more likely to be willing to surf in colder waters than were those who had mild EAEs (odds ratio 4.3). CONCLUSIONS: EAEs are more prevalent in cold water surfers, and additional years surfing increase one's risk not only for developing an EAE but also for developing more severe lesions.

Exostosis of the external auditory canal: a technical note.Otol Neurotol. 2002 May;23(3):260-1.

OBJECTIVE: To describe the author's method of managing occlusive exostosis of the external auditory canal. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral ambulatory otology clinic. PATIENTS: A case series of patients treated sequentially by the author over 15 years, all of whom had occlusive external auditory canal exostoses that could not be treated by medical management. INTERVENTION: Permeatal surgical removal of the anterior exostosis only. MAIN OUTCOME MEASURE: Surgical relief of occlusive external auditory canal disease by restoration of hearing and absence of infection with persistence of an external auditory canal and no symptoms of recurrence. RESULTS: A total of 8 men were treated by anterior exostosis removal. Follow-up continued on these patients for a period of 5 to 15 years after the operation, and none showed any evidence of recurrence or tendency to narrowing of the deep ear canal. One patient incurred a tympanic membrane perforation at escostosis surgery that was repaired during the operation. CONCLUSION: Anterior exostosis removal by a permeatal route is a safe, rapid, and effective method of relieving patients of occlusive external auditory canal exostosis. By leaving the posterior exostosis intact, patients are not put at risk for injury to the facial nerve, chorda tympani nerve, or ossicles. When the deep ear canal is drilled blind, there are no landmarks to indicate the true path of the external canal.

Results and extraordinary complications of surgery for exostoses of the external auditory canal.HNO.2000 Feb;48(2):125-8.

We present a retrospective study on 22 operations of exostosis of the external auditory canal in 20 patients. 8 patients were passionated by water sports. The most frequent indication for surgery (13 operations) was recurrent external otitis or ceruminal obstruction. In 7 cases the need for a wider access to the middle ear indicated surgery. Surgery was usually performed as an outpatient procedure, maximum hospitalization was 3 days. The mean healing period was 6 (3-10) weeks. Mean follow up was 43 (3-110) months. There were no severe intraoperative complications such as facial paresis, lesions of the ossicles or of the inner ear. As intraoperative complications we found 2 perforations of the tympanic membrane, 2 expositions of the capsule of the mandibular joint, one of which was followed by chronic pain. As postoperative complications we found an early soft tissue stenosis of the external auditory canal and one late soft tissue stenosis which recurred after revision surgery. No recurrence of exostosis was seen. We describe an up to now unknown complication: the appearance of bilateral petrositis caused by staphylococcus epidermidis after bilateral surgery in an otherwise healthy patient. This study confirms that severe complications are rare, minor ones however relatively common. And that also minor complications may have a troublesome follow. Therefore and because of the potential of severe complications indication for surgery must be made cautiously and risks of the operation must not be underestimated.

Prevalence of external auditory canal exostoses in surfers.Arch Otolaryngol Head Neck Surg. 1999 Sep;125(9):969-72.

OBJECTIVE: To determine (1) the prevalence of external auditory exostoses in a population of surfers and (2) the relationship between the length of time spent surfing and the prevalence, severity, and location of the exostoses. DESIGN: Cross-sectional epidemiological study. SETTING: General community. PATIENTS: Three hundred seven avid surfers (93.5% males and 6.5% females; age distributions: 11.2% were < or =20, 67.9% were 21 to 40, 17.5% were 41 to 50, and 3.3% were >50 years). MAIN OUTCOME MEASURES: Questionnaires focusing on surfing habits (number of years, geographic region, and number of days per year of surfing) were correlated with otoscopic findings. A simple grading system was devised, based on the degree of external auditory canal stenosis. Grades of normal, mild, moderate, and severe corresponded to 100%, 99% to 66%, 65% to 33%, and less than 33% effective patent surface area, respectively. RESULTS: There was a 73.5% overall prevalence of external auditory exostoses and a 19.2% overall prevalence of osteomas in the group studied. Of 441 ears with exostoses, 54.2% were mild, 23.6% were moderate, and 22.2% were severe. Of individuals who had surfed for 10 years or less, 44.7% had normal ear canals and only 6% had severely obstructed auditory canals. In comparison, in the group that had surfed for longer than 20 years, only 9.1% had normal auditory canals and 16.2% were severely affected. Of surfers with no exostoses, 61.1% had surfed for 10 years or less. In contrast, of surfers with severe exostoses, 82.4% had surfed for more than 10 years. Finally, the lesions seemed to affect all external auditory canal quadrants equally. CONCLUSION: A positive association exists between the amount of time individuals spend surfing and the presence and severity of exostoses of the external auditory canal.

Fifty-four surfers and 38 surf life savers were examined and questioned in order to determine the prevalence of exostoses. Seventy-three per cent had evidence of body exostoses in the external auditory meatus. Forty per cent had their ear canals narrowed by 50% or more. The relationship between the number of years spent surfing or life saving and the extent of canal stenosis was highly significant (P < 0.00001). Left and right ears were affected equally in this series and the obstruction appears to begin after approximately 7 years and is further aggravated by continued surfing. Over 90% of subjects who had participated for longer than 10 years had some evidence of exostoses. There was no significant association between the number of days per year or the number of hours per day spent surfing and the development of surfer's ear in this sample. Those who participated in their water sport over winter had significantly more exostoses than those who did not (P < 0.0001). Those who lived in the South Island (colder water) had more surfer's ear than those in the North Island (warmer water).

Many reports suppose that the development of aural exostosis depends on the action of an irritative stimulus like frequent and repeated cold water contact. This survey studies the incidence of this lesion in a group of 433 athletes practicing aquatic sports on a highly competitive level. Among these, water activities like sailing and deep-sea diving, which up to now were never considered, were also studied. 32 exostoses were found to affect 12 subjects monolaterally and 20 subjects bilaterally. Not one of a control group of 476 athletes was found to be affected by aural exostosis. For each athlete in this study the following parameters are considered: age and sex, type of sport, total amount of hours spent in water contact, aural pathology history and otoscopic findings. The authors suggest the existence of facilitating factors other than total water contact time, as shown by the absence of a precise correlation between this parameter and the presence of the aural hyperostotic lesion.

Neoplasms of the External Ear ;

Squamous Cell Carcinoma of the External Ear ;

Verrucous Carcinoma of the External Ear ; 

Basal cell carcinoma of the External Ear ;

Ceruminous Adenoma of the External Ear ;

Pleomorphic Adenoma of the External Ear ;

Syringocystadenoma Papilliferum of the External Ear ;

Cylindroma of the External Ear ;

Ceruminous Adenocarcinoma of the External Ear ;

Adenoid Cystic Carcinoma of the External Ear ;

Melanocytic Tumours of the External Ear ;

Rhabdomyosarcoma of the External Ear;

Langerhans Cell Histiocytosis of the Ear

Primary Lymphoma of the Ear