Otitis externa.

Otitis externa is a widespread condition which may occur in many different forms. Allergic reactions, bacteria, pathologic changes secondary to seborrheic dermatitis, and fungi, singly or in association with each other, are among the causative factors considered. In the treatment of this condition, the diversity of causative factors which may be present must be recognized and evaluated; after one factor has been eliminated, another often remains to be conquered. The apparent confusion of reports regarding etiology and treatment is in fact due to confusion regarding the fundamental nature of the condition. Good results usually can be obtained by careful evaluation of the factors in each case and adaptation of treatment to the circumstances.