ABSTRACT
Infections in otitis externa are invariably secondary and most commonly involve commensal or environmental organisms. Primary causes of otitis externa include hypersensitivity, ectoparasites, foreign bodies, neoplasia, endocrinopathies, autoimmune disease and keratinisation disorders. The only way to manage and prevent recurring otitis externa is to identify and manage the primary cause. The clinical features will vary from individual to individual because of variation in primary cause, predisposing conditions, perpetuating factors, secondary infections and expression of the disease. In many uncomplicated cases of otitis externa, the type of cleaner used may be less important than the actual act of cleaning the ears and it is important to demonstrate effective ear-cleaning techniques to owners. Topical antibiotics are more effective than oral antibiotics for resolving otitis externa. Systemic therapy may be less effective in otitis externa because bacteria are present only in the external ear canal and cerumen, there is no inflammatory discharge and penetration to the lumen is poor.
