Pathophysiology

The causes or pathogenesis are usually multiracial. Several risk factors put up predispose to infection or initiate inflammation and subsequently the infected process. Intact distribution channel skin and cerement production have a protective effect against infections. This is secondary to the fact that cerement produces a pH in the pinnule provide that is slightly acidic. On the other hand, partition of skin integrity, insufficient cerement production, or blockage of the ear line with cerement (which promotes irrigate retention) can predispose to Infection.Skin Integrity can be Injured by direct aroma, heat, and moisture or persistent water In the ear supply. Such damage Is thought to be essential for initiation of the inflammatory process. Subsequently, edema may result, followed by bacterial vaccination and overgrowth. In Otis External, the infection is caused by bacteria or fungi. Scratching, inserting objects into the ear transmission channel, or moisture (from swimmi ng, for example can make the ear canal vulnerable to Infection.The external auditory canal is a cylinder quantity approximately 2. 5 CM in length and 7. 0 to 9. 0 mm in width, extending from the conchs cartilage of the auricle to the humanity membrane . It Is dissever Into a squint (outer) cartilaginous portion that occupies approximately one-third of the canal and a medial (Inner) bony portion that occupies the remaining two-thirds. Their junction is termed the set and is the narrowest region of the ear canal.The outer cartilaginous portion is lined by thicker skin with numerous addenda structures including cerement glands, sebaceous glands, and hair follicles. The inner bony portion of the canal contains thin skin without subcutaneous tissue. The dermis In this area Is In direct contact with the underlying peritoneum. Thus, minimal spunk or Instrumentation of the bony canal causes significant pain and/or Injury. The Inferior tympanis recess Is a small depression In the defi cient medial aspect of the ear canal, adjacent to the tympanis membrane.Debris can collect in this area and cause or perpetuate infection. The lining of the ear canal is a exaggerating exogamous epithelium that undergoes continual sloughing. Epithelial migration is a course occurring cleaning process for the ear canal that allows egress of keratin detritus and cerement. Epithelial migration begins in the center of the tympanis membrane and continues out to the medial, then lateral aspects of the ear canal.The ear canal is bound superiorly by the middle cranial Foss, interiorly by the temporarinesss Joint and paranoid region, medially by the tympanis membrane, posterior by the mastoid cavity, and inferiorly by the skull base and soft tissues of the neck. These boundaries have particular wideness when considering the potential complications of external Otis. The fissures of Sanatoria are a series of embryological fissures In the frontal aspect of the fissures also allow potential sp read of ear canal disease to the paranoid region, temporarinesss Joint, and soft tissue of the upper neck.