Symptom >> Otorhinolaryngology >> ENT

External auditory canal stenosis

Introduction
Cause
Examine
Diagnosis

Introduction

Introduction The external auditory canal is a curved tube from the outer ear door to the tympanic membrane, with a total length of about 2.1-2.5 cm. The outer third is the cartilage and the inner 2/3 is the bony. The narrowing of the external auditory canal includes both congenital and acquired. Otitis externa can also cause narrowing of the external auditory canal.

Cause

Cause

Reasons for narrowing of the external auditory canal:

Congenital external auditory canal stenosis and atresia are embryonic developmental disorders caused by the developmental malformations of the first sulcus and the posterior part of the first and second sacral arches.

Acquired external auditory canal stenosis and atresia are often caused by burns, inflammation, tumors, trauma and surgery in the external auditory canal. Diffuse otitis externa is caused by Gram-negative bacteria such as Escherichia coli, Pseudomonas aeruginosa or Proteus vulgaris; Staphylococcus aureus; or rarely fungi. The external auditory canal is often caused by Staphylococcus aureus. Some people (such as allergic reactions, psoriasis, eczema or seborrheic dermatitis) are particularly susceptible to otitis externa. Predisposing factors include influent or various irritants such as hair sprays or hair dye solutions entering the external auditory canal and ear damage due to the cleaning of the ear canal. Through the desquamation of the epithelium, the movement of the outer surface of the tympanic membrane is transmitted to the outside of the tympanic membrane by the motion of the conveyor belt, and the outer ear canal is cleaned by itself. The patient manually cleaned the external auditory canal (sweep ear) with a cotton swab, which interfered with the self-cleaning mechanism. Since the direction of the swab is opposite to the direction of epithelial desquamation activity, debris can be pushed into the ear canal to promote the accumulation of desquamation. Desquamation and sputum absorb the water entering the external auditory canal, causing the skin to soak, creating conditions for the invasion of pathogenic bacteria.

Examine

an examination

Related inspection

Otoscopy, ear examination, external auditory canal

Examination of the diagnosis of external auditory canal stenosis:

Acute otitis externa: acute onset, burning, itching, pain in the external auditory canal, diffuse congestion, swelling, epidermal erosion. It is first a thin secretion, which in turn becomes a purulent or purulent discharge. If the skin is swollen, it may cause narrowing or atresia of the external auditory canal, obscuring the tympanic membrane, causing tinnitus and hearing loss. In severe cases, the lymph nodes in the ear are swollen, tender, and general malaise.

Chronic otitis externa: long course of disease, more itching, a small amount of pus, mild hearing loss. The external auditory canal is congested or thickened, or covered with suede. There is a little pus or debris under the suede. Sometimes the molt is removed. The tympanic membrane can be turbid, thickened, and unclear.

Congenital external auditory canal stenosis and atresia:

1, congenital auricular deformity, no external auditory canal or only a small nest. Often associated with middle ear malformations.

2, deafness. Both sides affect the child's language learning due to deafness.

3, can be combined with mandibular dysplasia.

Acquired external auditory canal stenosis and atresia:

1, there are external auditory canal inflammation, burns, tumors, trauma and surgical history, there are deafness, or accompanied by tinnitus, earache, ear pus.

2, the external auditory canal has scar tissue hyperplasia and other blockages.

3, pure tone audiometry is the sound of .

4, mastoid X-ray film visible external auditory canal stenosis or atresia.

Diagnosis

Differential diagnosis

Differential diagnosis of external auditory canal stenosis:

Otitis externa can be divided into two categories, one is localized otitis externa, also known as external auditory canal. The other type is diffuse inflammation of the external auditory canal skin, also known as diffuse otitis externa. When the external auditory canal skin trauma or local resistance is reduced, it is easy to develop, such as ear digging, swimming water infusion, and stimulation of suppurative long-term pus. In addition, there are allergies and easy recurrence. Common pathogens are Staphylococcus aureus, Streptococcus, Pseudomonas aeruginosa and Proteus. Localized otitis externa examination has auricular traction pain and tragus tenderness, and localized cartilage of the external auditory canal has redness and swelling. Severe swelling of the posterior wall of the external auditory canal can make the posterior sulcus and mastoid area red and swollen. Diffuse otitis externa examination also has auricular traction pain and tragus tenderness, diffuse redness of the external auditory canal skin, accumulation of secretions on the wall of the external auditory canal, narrowing of the external auditory canal, and swelling of the periorbital lymph nodes. The external auditory canal has thickened skin, chapped, desquamation, and secretions, which can even cause narrowing of the external auditory canal.