Fig. 2.

Acquired atresia of the external auditory canal can be classified into 3 categories according to the underlying etiologic process. (1) Local pathologies affecting solely the EAC include mechanical injury (trauma or post-surgical), neoplastic (temporal bone and EAC benign and malignant tumors), radiation induced or local inflammation and fibrosis secondary to recurrent bouts of infectious otitis. (2) Systemic disorders may also affect the EAC though the exact underlying pathophysiologic mechanism is not fully understood and this includes immune mediated and collagen vascular diseases, endocrinopathies, systemic dermatopathies and metabolic disorders. (3) Some forms, however, remain idiopathic.