There is clear evidence that otitis media with effusion is highly related to an allergic diathesis. When this converts to chronic draining otitis media, the allergic component would seem to still be relevant, although direct evidence is scant (17-19). Therefore, the surgeon must consider allergy evaluation, based on a patient history of other allergic diatheses, especially of the unified respiratory epithelium. Patients with chronic draining ear and allergic rhinitis, chronic rhinosinusitis, and asthma are strong candidates for allergy workup before contemplating surgical treatment.
Contact allergy to chemicals used in ear drops is the most common type of dermatologic otitis externa. Hairsprays, dyes, and cosmetics can also result in an eczematoid and draining otorrhea. If the source of external canal weeping is not obvious, routine patch testing is strongly suggested (20). The "autoeczematization" (ID) reaction, which is an autoimmune reaction that may involve only the external auditory canal, has been recorded for over 70 years in the otolaryngology literature. Recent studies confirm that this is due to a local reaction to distant fungus infections, most commonly dermatophytid in the feet and inguinal area. Control of the primary fungal infection with prolonged antifungal systemic treatment will nearly always control the ear reaction (21,22). There are other less-common dermatologic conditions that may focus on the ear. Atopic dermatitis, which has recently been found to result from a superantigen reaction to Staphylococcus aureus exotoxin, has been implicated in otitis externa (23). A special cause of contact dermatitis is the overuse of some ear drops in which the preservative or a component of the drop itself irritates the ear. In these individuals, the drops have often been administered to clear up an infectious etiology of otorrhea. In the case of contact dermatitis, the infectious otorrhea will stop as the drops become effective and then will begin again with a slightly different character as the drops become noxious.
Most autoimmune and contact allergy reactions of the external auditory canal and pinna skin are treated primarily by eliminating the source and controlling the local reaction with topical steroids. Care must be taken to avoid skin atrophy caused by prolonged topical steroid use. Necrosis of external auditory canal skin and temporal bone exposure may occur.
Was this article helpful?