Auditory exostoses as an aquatic activity marker: a comparison of coastal and inland skeletal remains from tropical and subtropical regions of Brazil

External auditory exostosis among surfers: a comprehensive and systematic review

OBJECTIVE

External auditive exostosis (EAE), known as surfer's ear, is a temporal bone outgrowth resulting from ear exposure to cold air and water. This review aims to shed light on the prevalence of EAE among worldwide surfers.

METHODS

By a thorough retrieval of the PubMed, we found all original investigations performed on EAE among suffers. The retrieval time was from the construction of the database to December 2022. Agency for Healthcare Research and Quality (AHRQ) methodology checklist for assessing the quality of cross-sectional/prevalence study was performed.

RESULTS

19 articles were selected involving 2997 surfers on whom 2032 presented EAE. The prevalence of EAE was ranged from 53 to 90% with a mean at 67.8%. 3 investigations were performed from USA, five from UK and Ireland, five from Australia and New Zealand and six from Japan and Europe.

CONCLUSION

Cold water exposure, combined with wind and prolonged surfing activity, contributes to the development of EAE. Symptoms range from mild discomfort to hearing loss and recurrent infections. Preventive measures, such as raising awareness and promoting the use of ear protection, are crucial. Further research is needed to improve prevention strategies and understand the underlying mechanisms of EAE.

External auditory exostoses in wind-dependent water sports participants: German wind- and kitesurfers

Purpose

Cold water and wind are known to cause exostoses of the external auditory canal. Different prevalences in different sports have been described in the literature. The aim of this study was to investigate the prevalence of external auditory exostosis (EAE) and EAE severity in coastal German wind- and kitesurfers who are exposed to cold water and strong winds. Furthermore, influencing factors such as the total exposure time and frequency of activity as well as the correlations between symptoms and the severity of EAE were investigated.

Methods

In this retrospective cross-sectional study, German non-professional wind- and kitesurfers along the North and Baltic Sea coasts were recruited between September 2020 and November 2020. Each participant was interviewed about exposure time and otological symptoms and underwent bilateral video otoscopic examination to determine EAE severity.

Results

A total of 241 ears from 130 subjects were analysed. The prevalence of EAE was 75.1%. In 19.9% of the participants, severe EAE was found. Exposure time and the frequency of activity had significant effects on the severity of EAE. Compared to surfers, EAE growth seems to progress faster in wind- and kitesurfers. The number of symptoms requiring medical treatment increased when two-thirds of the external auditory canal was obstructed.

Conclusion

The prevalence of EAE in wind- and kitesurfers is high. Total exposure time and the frequency of activity influence EAE growth. EAE growth occurs faster in wind- and kitesurfers than in surfers. The additional influence of wind and the evaporative cooling of the EAC are thought to be responsible. The results of this study should increase awareness of the dynamics of EAE among ENT specialists and improve patient counselling.

External auditory exostoses and early Neolithic aquatic resource procurement in Cyprus: Results from Cypro-PPNB Kissonerga-Mylouthkia in regional context

OBJECTIVE

This research is designed to evaluate the occurrence of external auditory exostoses (EAEs) in skeletal remains from the oldest known water wells in the world (Kissonerga-Mylouthkia, Cyprus, 8,200-7,200 BCE).

MATERIALS

Six individuals (MNI = 6), five fragmentary temporalia, two preserved auditory canals.

METHODS

Macroscopic and microscopic (up to x30) observation, with illumination; presence, type, side, severity, occlusion, number, and position of bony growths recorded.

RESULTS

Bony growths within two auditory canals were discovered. Differential diagnosis includes osteomata and external auditory exostoses, with the latter consistent with the bony growths (Grade 1 EAEs, two adult males, one with single, another with two EAEs).

CONCLUSIONS

The emergence of the Neolithic in Southwest Asia is thought to involve increases in dietary breadth among foraging societies (Broad-Spectrum Revolution). EAEs likely indicate maritime activity in this context, given the lack of freshwater bodies, and zooarchaeological evidence points to dietary and other uses of maritime organisms.

SIGNIFICANCE

This EAE evidence is the oldest known in maritime contexts in Eastern Mediterranean and the Middle East, and first in Cyprus. It contributes towards understanding the initial colonization events by Neolithic farming communities in the 9th millennium BC, and the emergence of broad-spectrum economies at the dawn of the Neolithic in Southwest Asia, crucial for re-considerations of paradigms on the transition to the Neolithic way of life in the Near East.

LIMITATIONS

Only a few skeletal remains from these prehistoric contexts were available for observation.

SUGGESTIONS FOR FURTHER RESEARCH

Further intensive review of Cypriot skeletal collections for EAEs is advised.

External auditory exostoses among western Eurasian late Middle and Late Pleistocene humans

External auditory exostoses (EAE) have been noted among the Neandertals and a few other Pleistocene humans, but until recently they have been discussed primary as minor pathological lesions with possible auditory consequences. An assessment of available western Eurasian late Middle and Late Pleistocene human temporal bones with sufficiently preserved auditory canals (n = 77) provides modest levels of EAE among late Middle Pleistocene archaic humans (≈20%) and early modern humans (Middle Paleolithic: ≈25%; Early/Mid Upper Paleolithic: 20.8%; Late Upper Paleolithic: 9.5%). The Neandertals, however, exhibit an exceptionally high level of EAE (56.5%; 47.8% if two anomalous cases are considered normal). The levels of EAE for the early modern humans are well within recent human ranges of variation, frequencies which are low for equatorial inland and high latitude samples but occasionally higher elsewhere. The Early/Mid Upper Paleolithic frequency is nonetheless high for a high latitude sample under interpleniglacial conditions. Given the strong etiological and environmental associations of EAE development with exposure to cold water and/or damp wind chill, the high frequency of EAE among the Neandertals implies frequent aquatic resource exploitation, more frequent than the archeological and stable isotopic evidence for Middle Paleolithic/Neandertal littoral and freshwater resource foraging implies. As such, the Neandertal data parallel a similar pattern evident in eastern Eurasian archaic humans. Yet, factors in addition to cold water/wind exposure may well have contributed to their high EAE frequencies.

External auditory exostoses in the Xuchang and Xujiayao human remains: Patterns and implications among eastern Eurasian Middle and Late Pleistocene crania

In the context of Middle and Late Pleistocene eastern Eurasian human crania, the external auditory exostoses (EAE) of the late archaic Xuchang 1 and 2 and the Xujiayao 15 early Late Pleistocene human temporal bones are described. Xujiayao 15 has small EAE (Grade 1), Xuchang 1 presents bilateral medium EAE (Grade 2), and Xuchang 2 exhibits bilaterally large EAE (Grade 3), especially on the right side. These cranial remains join the other eastern Eurasian later Pleistocene humans in providing frequencies of 61% (N = 18) and 58% (N = 12) respectively for archaic and early modern human samples. These values are near the upper limits of recent human frequencies, and they imply frequent aquatic exposure among these Pleistocene humans. In addition, the medial extents of the Xuchang 1 and 2 EAE would have impinged on their tympanic membranes, and the large EAE of Xuchang 2 would have resulted in cerumen impaction. Both effects would have produced conductive hearing loss, a serious impairment in a Pleistocene foraging context.

External auditory exostoses and hearing loss in the Shanidar 1 Neandertal

The Late Pleistocene Shanidar 1 older adult male Neandertal is known for the crushing fracture of his left orbit with a probable reduction in vision, the loss of his right forearm and hand, and evidence of an abnormal gait, as well as probable diffuse idiopathic skeletal hyperostosis. He also exhibits advanced external auditory exostoses in his left auditory meatus and larger ones with complete bridging across the porus in the right meatus (both Grade 3). These growths indicate at least unilateral conductive hearing (CHL) loss, a serious sensory deprivation for a Pleistocene hunter-gatherer. This condition joins the meatal atresia of the Middle Pleistocene Atapuerca-SH Cr.4 in providing evidence of survival with conductive hearing loss (and hence serious sensory deprivation) among these Pleistocene humans. The presence of CHL in these fossils thereby reinforces the paleobiological and archeological evidence for supporting social matrices among these Pleistocene foraging peoples.

Aural exostoses (surfer's ear) provide vital fossil evidence of an aquatic phase in Man's early evolution

For over a century, otolaryngologists have recognised the condition of aural exostoses, but their significance and aetiology remains obscure, although they tend to be associated with frequent swimming and cold water immersion of the auditory canal. The fact that this condition is usually bilateral is predictable since both ears are immersed in water. However, why do exostoses only grow in swimmers and why do they grow in the deep bony meatus at two or three constant sites? Furthermore, from an evolutionary point of view, what is or was the purpose and function of these rather incongruous protrusions? In recent decades, paleoanthropological evidence has challenged ideas about early hominid evolution. In 1992 the senior author suggested that aural exostoses were evolved in early hominid Man for protection of the delicate tympanic membrane during swimming and diving by narrowing the ear canal in a similar fashion to other semiaquatic species. We now provide evidence for this theory and propose an aetiological explanation for the formation of exostoses.

External ear canal exostosis and otitis media in temporal bones of prehistoric and historic chilean populations. A paleopathological and paleoepidemiological study

CONCLUSIONS

External ear canal exostosis is more prevalent in northern coastal groups than in the highlands, suggesting that ocean activities facilitate the appearance of exostosis. However, southern coastal groups exposed to colder ocean water have a lesser incidence of exostosis, possibly due to less duration of exposure. There was a high incidence of otitis media in all groups of native population in Chile. One coastal group had a higher incidence, presumably due to racial factors.

BACKGROUND

This is a paleopathological and paleoepidemiological study in temporal bones which assesses external ear canal exostosis and otitis media in prehistoric and historic native populations in Chile.

MATERIALS AND METHODS

A total of 460 temporal bones were evaluated for exostosis (ex) and 542 temporal bones were evaluated for otitis media (om). The study involved four groups: (1) Prehistoric Coastal (400-1000 AD) populations in Northern Chile (Pisagua-Tiwanaku) (22 temporal bones ex; 28 om); (2) Prehistoric Highland (400-1000 AD) populations in Northern Chile (292 temporal bones ex; 334 om); (3) Pisagua-Regional Developments (coastal) in Northern Chile (1000-1450 AD) (66 temporal bones ex; 82 om); and (4) Historic (1500-1800 AD) coastal populations in Southern Chile (80 temporal bones ex: 18 Chonos, 62 Fuegians. 98 om: 22 Chonos, 76 Fuegians). Skulls were evaluated visually and with an operating microscope. In addition, the otitis media group was evaluated with Temporal bone radiology - -lateral XRays-Schuller view - to assess pneumatization as evidence of previous middle ear disease.

RESULTS

Prehistoric northern coastal groups had an incidence of exostosis of 15.91%, the northern highlands group 1.37%, and the southern coastal group 1.25%. There were changes suggestive of otitis media in: Pisagua/Tiwanaku 53.57%; Pisagua/Regional Developments 70.73%; Northern Highlands population 47.90%; Chonos 63.64%; and Fuegian tribes 64.47%.

Statecraft and expansionary dynamics: A Virú outpost at Huaca Prieta, Chicama Valley, Peru

Interpolity interaction and regional control were central features of all early state societies, taking the form of trade-embedded in political processes to varying degrees-or interregional conquest strategies meant to expand the polity's control or influence over neighboring territories. Cross-cultural analyses of early statecraft suggest that territorial expansion was an integral part of the process of primary state formation, closely associated with the delegation of authority to subordinate administrators and the construction of core outposts of the state in foreign territories. We report here on a potential case of a core outpost, associated with the early Virú state, at the site of Huaca Prieta in the Chicama Valley, located 75 km north of the Virú state heartland on the north coast of Peru. This site is discussed in the context of other possible Virú outposts in the Moche Valley, Pampa La Cruz, and Huaca Las Estrellas, and as part of a broader reflection on expansionary dynamics and statecraft.

Exostoses of the external auditory canal

Ear canal exostoses are bilateral, usually symmetric multiple bony growths occurring in the medial portion of the external auditory canal. Also known as surfer’s ear, exostosis is thought to be a reactive process from repeated stimulation by cold water and is much more common than external auditory osteoma. Exostoses are usually asymptomatic and discovered on routine otoscopy. Indications for surgical treatment are recurrent otitis externa, hearing loss, otalgia and other conditions in which access medial to the exostoses is required. Surgery is not risk-free and postoperative complications are the most important factor for negative impact on the patient’s health-related quality of life. This review offers an overview of the recent advances in the understanding of this condition, with a special focus on the etiology and physiopathology of this condition, the different surgical procedures and their outcomes, the risk factors for recurrence and the results of preventive measures. Finally, this review suggests the need for the otological surgeon to acquire a great deal of experience before undertaking surgical treatment of exostoses as it is a challenging operation and, besides expertise, demands great patience and extreme care in order to achieve good results.

The effects of surfing behaviour on the development of external auditory canal exostosis

To examine how individual surfing behaviour affects the development of external auditory canal exostosis and to produce a model to predict exostosis severity. A standardised questionnaire was completed and each participant underwent an otoscopic examination. Surfers were recruited from August to October 2011 from surfing competitions and from colleges in the South West of England. 207 surfers were included, 53 % had evidence of external auditory canal; exostosis: grade 1, 23%; grade 2, 16%, grade 3, 16%. This risk of exostosis significantly increased with (1) surfing for 6 or more years, (2) surfing in the winter months, (3) surfing five or more times per month in the winter and (4) reported ear symptoms. Interestingly, participation in other water sports and wearing earplugs or a hood reduced the risk of developing exostosis. Surfers who surf in England are at significant risk of exostosis. A probability model was designed, incorporating different surfing behaviours and ear symptoms, the first of its kind in exostosis research. This model will be a useful tool for raising awareness of external ear canal exostosis in the surfing community and in assessing individual need for surgical intervention.

Exostoses of the paranasal sinuses

While bony exostoses of the external auditory canal have long been recognized as a complication of cold-water swimming, bony exostoses of the paranasal sinuses have not been previously reported. We present an unusual case of multiple exostoses of the paranasal sinuses, which began coincident with nasal irrigation with cold gentamicin solution. The patient had had prior endoscopic sinus surgery. Topical antibiotic gentamicin irrigation lessened recurrence of bacterial sinus episodes. He admitted to using the irrigation directly from the refrigerator daily for two years. A biopsy was consistent with exostosis. Patients should be counseled to avoid irrigating their paranasal sinuses with cold irrigants. Laryngoscope, 2010.

Water-related occupations and diet in two Roman coastal communities (Italy, first to third century AD): correlation between stable carbon and nitrogen isotope values and auricular exostosis prevalence

The reconstruction of dietary patterns in the two Roman imperial age coastal communities of Portus and Velia (I-III AD) by means of stable isotope analysis of bone remains has exposed a certain degree of heterogeneity between and within the two samples. Results do not correlate with any discernible mortuary practices at either site, which might have pointed to differential social status. The present study tests the hypothesis of a possible connection between dietary habits and occupational activities in the two communities. Among skeletal markers of occupation, external auricular exostosis (EAE) has proved to be very informative. Clinical and retrospective epidemiological surveys have revealed a strong positive correlation between EAE development and habitual exposure to cold water. In this study, we show that there is a high rate of occurrence of EAE among adult males in both skeletal samples (21.1% in Portus and 35.3% in Velia). Further, there is a statistically significant higher prevalence of EAE among those individuals at Velia with very high nitrogen isotopic values. This points to fishing (coastal, low-water fishing) as the sea-related occupation most responsible for the onset of the ear pathology. For Portus, where the consumption of foods from sea and river seems to be more widespread through the population, and where the scenario of seaport and fluvial activities was much more complex than in Velia, a close correlation between EAE and fish consumption by fishermen is less easy to establish.

Exostoses of the external auditory canal in white-water kayakers

OBJECTIVES/HYPOTHESIS

Exostoses of the external auditory canal are benign bony tumors associated with frequent cold-water exposure. Obstruction may lead to conductive hearing loss and recurrent otitis externa, requiring surgical correction when symptoms become intolerable. This study aimed to characterize the prevalence of exostoses in white-water kayakers and identify associated risk factors and protective measures.

STUDY DESIGN

Cross-sectional.

METHODS

Six hundred eleven white-water kayakers from across the United States were included in the study. Percent occlusion was graded as minimal (<25%), moderate (25%-75%) or severe (>75%). Subjects completed a survey of risk factors and protective measures. Kruskal-Wallis and chi(2) tests were performed to determine significant associations with percent occlusion. A multivariate proportional odds regression model was fit to adjust for confounding between the variables.

RESULTS

The prevalence of exostoses in kayakers was 79% (482/611); 13% (78/611) had >or=75% occlusion. Percent occlusion was associated with total years kayaked (P < .001), frequency >or=1 day/week (P < .001), male gender (P < .001), and increasing age (P = .005), although frequency, gender, and age were confounded by total years. Styles that involve repeated submersion were also associated with greater occlusion (freestyle, P = .036; squirt, P = .016). Subjects who used earplugs for a greater proportion of their kayaking career were less likely to have exostoses (P < .001). When adjusted for confounding, only total years (P = .0003) and age (P = .0027) remained significant.

CONCLUSIONS

Kayakers are the first inland population to experience exostoses at the rates seen in coastal populations (e.g., surfers). When used long-term, earplugs may be protective.

How does a riverine setting affect the lifestyle of shellmound builders in Brazil?

The contact of inland and coastal prehistoric groups in Brazil is believed to have been restricted to regions with no geographical barrier, as is the case in the Ribeira de Iguape valley. The inland osteological collection from the riverine shellmound Moraes (5800-4500 BP) represents a unique opportunity to test this assumption for this region. Despite cultural similarities between riverine and coastal shellmounds, important ecological and site distribution differences are expected to impact on lifestyle. The purpose of this study is thus to document and interpret health and lifestyle indicators in Moraes in comparison to coastal shellmound groups. Specifically we test if the rare evidence of fish and mollusc remains in the riverine shellmound led to (a) higher caries rates and (b) lower auditory exostosis frequency and (c) if the small size of the riverine shellmound translates into reduced demographic density and thus rarity of communicable infectious diseases. Of the three hypotheses, (a) was confirmed, (b) was rejected and (c) was partly rejected. Bioanthropological similarities between Moraes and coastal shellmounds include auditory exostoses with equally high frequencies; significantly more frequent osteoarthritis in upper than in lower limbs; cranial and dental morphological affinities and low frequencies of violent trauma. However, there are also important differences: Moraes subsisted on a much broader protein diet and consumed more cariogenic food, but showed a stature even shorter than coastal groups. Thus, despite the contact also suggested by treponematoses in both site types, there was enough time for the people at the riverine site to adapt to local conditions.

An Evaluation of Auditory Exostoses in 621 Prehistoric Human Skulls from Coastal Brazil

Auditory exostoses are bone anomalies located on the floor of the external auditory canal. They frequently develop in individuals who participate in water sports and other aquatic activities. Their etiology is probably multifactorial; development seems to be triggered by regular exposure to cold water, as well as to low air temperatures and/or cold winds. The presence of auditory exostoses has been recorded in human skull fossils that date back approximately 250,000 years. We conducted a study of auditory exostoses in 621 skulls of adult humans who had been part of a marine-dependent population that lived on the Brazilian coast between 5,400 and 800 years ago. The overall frequency of exostoses was 22%, but there was a great variance among different subgroups (0 to 56%). In this article, we propose some possible explanations for this variance. We also hope that our study will stimulate multidisciplinary research aimed at deciphering the intricate bony messages contained in cryptic archaeologic remains.