Bacteria, fungi and parasites asa result of infections, we observe progressive pathological changes in the external auditory canal [narrowing, glandular hyperplasia, edema, surface folding, fibrosis, calcification, pathological growths] and otitis media Allergy flea, atopic, food, drug - characteristic symptoms are hyperplastic skin changes, crusts, erythema or exudate Hormonal disorders inflammation may be caused by hypothyroidism, through lymphocytic inflammation of this organ Autoimmunity infections caused by a disturbed defense mechanism of the ear skin Injury and others foreign body/irritant, hair, polyps, tumors