Exostosis is the medical term for an abnormal growth of bone within the ear canal. It is more commonly referred to as surfer’s ear. This common name derives from the fact that the most common cause of exostosis is frequent exposure to cold water, making this a condition that affects surfers at a higher rate than the average population. Exposure to wind and cold water causes the bone surrounding the ear canal to thicken and constrict the ear canal, sometimes to the point of complete blockage (known as “occlusion”) which can lead to substantial conductive hearing loss. An exostosis growth can result from any activity that exposes the participant to cold, wet and windy conditions such as skiing, kayaking, fishing, sailing or diving.
Most patients who develop an exostosis are in their mid-to-late 30s but those with significant cold water exposure such as surfers can develop the condition earlier. This is due to the slow progression of bone growth from years of cold weather exposure.


The normal ear canal is 5-8mm in diameter (about as thick as a pencil). As the narrowing of the canal from exostosis progresses, this diameter gets substantially reduced, to the point of total closure if the exostosis remains untreated. Exostosis in not necessarily harmful by itself, but the ear canal construction from the bony growth can trap cerumen (ear wax) and other debris within the ear canal, which may lead to repeated ear infections.


Exostosis symptoms of include a decrease in hearing sensitivity possibly combined with an increased prevalence of ear infections. Early symptoms include water trapping in the ear canal after swimming. Sometime thereafter, debris trapping and infections make surgery necessary. Exostosis is most commonly treated by a surgical procedure to remove the growth. There are two different approaches to the surgery, the first uses a small incision behind the ear and the excess bone growth is removed using a surgical drill, and the second uses a drill to remove the bone growth from inside of the ear canal itself. After the surgery, it is important for the patient to avoid any cold water activities for 2-6 weeks in order to prevent complications or infections.


Repeated cold water exposure can cause regrowth of bone, but after surgical removal it is extremely rare to need the procedure a second time.


No. The bone growth is irreversible once formed.


Exostosis is preventable by following some basic safety precautions.

  • Avoid activity during extremely cold or windy conditions;
  • Use custom ear protection to prevent cold water exposure if cold or windy conditions are going to be common experiences such as with surfing or sailing. Custom ear plugs are created by making an impression of the ear canal and creating a plug that is customized to the individual patient. These plus are more comfortable and work better than over-the-counter one-size-fits-all solutions.
  • Use a swim cap or hood in addition to the ear plugs mentioned above;


  • In general, one ear may be much worse than the other. If so, this may be due to the prevailing wind direction in the areas most visited by the patient.
  • The widespread use of better wetsuits and dry suit technology has allowed people to participate in water sports in much colder waters, likely increasing the incidence and severity of exostosis for those who do not use proper ear protection.
  • Cold water surfers experience exostosis at a rate 600 % higher than warm water surfers.
  • The colder the water, the quicker exostoses grow.

Posted in: Ear, ENT, Service Section for ENT

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