[Exostoses of the external auditory canal. Is the cold water hypothesis valid for patients in continental areas?].

INTRODUCTION

Exostoses of the external auditory meatus are benign masses of tympanal bone that can lead to infections of the external auditory meatus in advanced cases and then need surgical treatment. Regular irritation of the auditory meatus by exposure to cold water was implicated in the causation of exostoses long ago. The present study investigates the cold water hypothesis in a patient group of continental origin. The surgical procedures and results are discussed.

STUDY DESIGN

Retrospective study.

MATERIALS AND METHODS

We present the epidemiological and aetiological data and postoperative findings recorded for 144 patients (167 procedures) who underwent surgical removal of exostoses from the external auditory meatus in the hospital in Würzburg within 11 years. In attempt to glean further information about the aetiology, patients were also asked to complete a questionnaire on participation in water sports and their symptoms before and since the operation.

RESULTS

Most of the patients (94%) had taken part in water sports for some years, more than 80% of them several times weekly. The most common indication for surgical removal was recurrent infection of the external ear. Although 50% of the patients reported improved hearing, no higher sound threshold was observed. Reversible complications (ear drum performation, tinnitus, opening of mastoid cells) were observed in 18% of the patients. One patient had a stenosis of the auditory canal caused by scar tissue.

CONCLUSIONS

Surgical removal of exostoses in the external auditory canal is frequently fraught with controllable complications. The indications for their surgical removal should be strictly applied; the presence of exostoses in isolation is not an acceptable indication for surgery. Removal of exostoses is an adequate way of avoiding recurrent external ear infections. Improved hearing can be expected only if the self-cleaning function of the external auditory meatus is improved.