Chronic suppurative otitis media is mostly caused by acute otitis media with a purulent inflammatory course of more than 6-8 weeks, with irreversible damage caused by lesions invading the middle ear mucosa, periosteum or reaching deep into the bone. It is often combined with chronic mastoiditis. This disease is one of the common diseases in otology and can cause serious intracranial and extracranial complications that can be life-threatening. It is characterized clinically by chronic or intermittent pus flow in the ear, tympanic membrane perforation and hearing loss. It affects mostly young adults and rarely occurs after the age of 40. Changming Zhang, Department of Otolaryngology, Xijing Hospital
Etiology and pathogenesis
The common pathogenic bacteria are Aspergillus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, etc. Among them, there are more Gram-negative bacilli, and there can be a mixture of two or more bacteria. Infections or mixed infections of non-bacteriophage anaerobic bacteria are gradually becoming more common. The common causative factors of this disease are.
1, delayed treatment and improper medication during the acute phase, etc.
2.Papillary dysplasia and difficulty in dissipating the lesion after it occurs.
3, secondary to acute infectious diseases such as scarlet fever, measles and pneumonia, acute necrosis of the middle ear mucosa, inflammation invading the mastoid process of the tympanic sinus, especially secondary to drug-resistant Aspergillus and Pseudomonas aeruginosa infections, which are very difficult to treat.
4, chronic diseases of the nose and pharynx and sinusitis, tonsillitis and hypertrophy of the proliferators, inflammatory secretions are easy to enter the pharyngeal canal, and the lesions prevent the drainage of the pharyngeal opening.
5, chronic peripheral diseases such as anemia, diabetes, tuberculosis and nephritis, etc., the body’s resistance is weakened.
6, Suffering from allergic diseases, such as allergic edema and exudation of the upper respiratory mucosa, involving the eustachian tube and middle ear.
7.Cholesteatoma, necrosis of the auditory bone or destruction of the outer lateral wall of the tympanic chamber occur in the upper tympanic chamber.
Pathological changes
I. There are three types of lesions according to their severity and risk.
The most common type is the simple type, also called the pharyngeal tympanic tube tympanic chamber type, in which the lesion is mainly confined to the tympanic chamber. The normal eustachian tube and the anterior tympanic chamber are covered by ciliated columnar epithelium containing glands, the posterior tympanic chamber, the tympanic sinus and the mastoid process are rectangular epithelium, and the auditory bones, muscles, ligaments and nerves within the tympanic chamber are surrounded by mucosa, forming many folds and shallow pockets, generally the mucosa is infected and inflamed, and if the treatment is timely, the tympanic membrane is perforated and the drainage is unobstructed, the inflammation can be cured quickly. Otherwise, the shallow pockets expand, the mucosal lesions become irreversible, and although there is little pus flow, there is more than long-term pus flow, or recurrent pus flow soon after dry healing. The papillae are mostly well gasified and unharmed.
2.Necrosis type is also called bone ulcer type. The mucosal tissue is extensively destroyed, and the auditory bone, tympanic ring, tympanic sinus and mastoid atrium can be hemorrhaged and necrosed, especially the relaxed part and the posterior tympanic chamber above the perforation, the pus is not much but the odor is great, the perforation can often see the granulation and polyp blocking the drainage, serious hearing loss, sometimes there can be headache and vertigo, the mastoid is mostly interstitial or sclerotic type.
3.Cholesteatoma type is also called dangerous type. Cholesteatoma is an overgrown epithelial mass in the tympanic chamber or sinus, which is surrounded by fibrous tissue and contains necrotic epithelium, keratinized material and cholesterol crystals. Because of its ability to compress and destroy bone, it is a malignant tumor, so it was erroneously called cholesteatoma in the past, but in essence it is not a tumor. The pus from the ear is not much but smells bad, and there are white fragments and bean curd-like cholesteatoma epithelial masses in the perforation. It can cause headache and dizziness, and is easily complicated by intracranial and extracranial complications due to extensive bone destruction, so it is called dangerous otitis media, and the mastoid is mostly sclerotic.
Second, inflammation of the middle ear mucosa can induce cholesteatoma containing cholesterol crystals and cholesterol granuloma, which is a cholesterol lipidosis (Choleatosis), but is only a granuloma and is very different from the epithelial mass of cholesteatoma. The main points of difference between the two in terms of etiology and pathology are.
1. Cholesterol granuloma is formed due to obstruction of the eustachian tube, formation of negative pressure in the tympanic chamber, exudation or formation of glue ear, capillary hemorrhage, precipitation of cholesterol crystals and hematoxylin on the epithelial surface, blue color of the tympanic membrane, mucosal edema of the papillae, typical microscopic manifestation of cholesterol granuloma, cholesterol crystals surrounded by foreign body giant cells, outer layer of fibrous granulation tissue, mostly seen in hemorrhagic necrotic lesions of the tympanic chamber, not It is not a predecessor of cholesteatoma and is not related to cholesteatoma formation.
2. Cholesteatoma occurs by two mechanisms.
(1) Congenital cholesteatoma is rare. It is an epithelial mass in the middle ear formed by an overgrowth of embryonic remaining epithelial tissue stimulated by certain factors. It is usually located in the upper tympanic chamber and may have no history of otitis media and a completely normal tympanic membrane, and then begins to flow pus due to secondary infection after outward expansion and penetration of the tympanic membrane.
(2) Acquired cholesteatoma is the result of hyperplasia of the epithelium due to local stimulation of purulent otitis media. Most people now accept the theory of epithelial migration, which means that the basal cells in the germinal layer of the outer ear canal have a special potential for proliferation and growth, and under the stimulation of otitis media, the basal cells proliferate and invade the submucosal connective tissue of the middle ear or form granulomas, while the submucosal sclerosis forms new bone, the mass increases in size, and the tympanic membrane is subsequently perforated. The epithelial masses that are formed become necrotic with the loss of the epithelial cortex and secondary infection, which can precipitate cholesterol and a variety of chemically decaying substances. Its destructive tissue properties resemble a tumor, so Wendt (1873) first named it cholesteatoma, which is not essentially a tumor, but it has been used for a long time and is subject to later correction. Another view is that it is pre-cholesteatoma when upper respiratory tract infection induces obstruction of the eustachian tube, negative pressure occurs in the tympanic chamber, and the loose part of the tympanic membrane invaginates, or the epithelium behind the external auditory canal falls into the tympanic sinus and forms a cystic bag. This period can last for several years, and timely removal of accumulated keratin during this period can prevent the formation of cholesteatoma. Otherwise, once the accumulated epithelial masses become infected, they can break into the tympanic cavity and form a perforation of the flaccid or marginal part and a cholesteatoma.
Clinical manifestations
I. Simple type
1. The attack is related to upper respiratory tract infection and water ingress in the ear, and the ear discharge is intermittent.
2. The secretion is mucous or mucopurulent, without odor, and the amount of pus increases during the acute attack.
The tympanic membrane perforation is located in the tense part, and the size and shape of the perforation are often different, it can be shown as a small central perforation, a small kidney-shaped perforation or a large perforation, but the tympanic membrane has residual edges, the drum ring is not destroyed, the mucosa of the tympanic chamber is smooth or mildly edematous, the auditory chain is mostly intact or only part of the hammer bone stalk is necrotic.
4, hearing damage is generally mild conductive deafness.
5.X-ray of mastoid or CT scan of temporal bone shows mastoid of pneumatization type or plate barrier type without bone destruction.
II. Bone ulcer type
1. Persistent flow of mucous pus from the ear, often with a foul odor. If there is bleeding from a granulation or polyp, the pus is mixed with blood or bleeding in the ear.
2. Marginal perforation of the tympanic membrane, large perforation of the tense part or complete absence. Through the perforation, there are buds or polyps in the tympanic chamber, and the polyps with a tip come out from the perforation, which can block the external ear canal and prevent drainage.
3. Patients often have more severe conductive deafness.
4. The mastoid x-ray has a translucent area with blurred edges. There are soft tissue shadows in the superior tympanic chamber, tympanic sinus and mastoid process on the CT scan of temporal bone, which may be accompanied by partial bone destruction.
III. Cholesteatoma type
1. Long-term ear pus flow, with varying amounts of pus, sometimes with blood, and a special foul odor; acquired primary cholesteatoma may have no history of ear pus flow in the early stage.
2. The tympanic membrane is perforated in the relaxed part or there is a marginal perforation in the posterior and superior part of the tense part, and sometimes there are grayish-white scaly or bean residue-like materials in the tympanic chamber from the perforation, with bad odor. In a few cases, a defect or collapse of the posterior superior wall of the external auditory canal is seen, and the lateral wall of the superior tympanic chamber bulges outward. If the loose part of the perforation is covered by a layer of scab, the diagnosis can be missed if the scab is not removed.
3. Hearing examinations generally have varying degrees of conductive deafness. Hearing impairment may be less severe at this time because of middle ear cholesteatoma or sarcoid can form pseudo-connections between the interrupted small auditory bones. In the late stage, it may spread to the cochlea and cause mixed deafness or sensorineural deafness.
4. Papillary X-ray or CT scan of the temporal bone shows areas of bone destruction in the superior tympanic chamber, tympanic sinus or papillae, with dense and neatly sclerotic edges.
Treatment of chronic suppurative otitis media
Simple type: After cleaning the local area, the middle ear pus must be cleared so that the medicinal solution can come into direct contact with the diseased tissue to increase the therapeutic effect.
Bone ulcer type: Clear the middle ear buds, unobstructed drainage, local cleanliness and dryness, and use bacterial-sensitive ear drops to drip the ear.
Cholesteatoma type: Once diagnosed, surgery should be performed in time to prevent serious complications.
Sterile instruments and dressings must be used when cleaning the external ear canal and middle ear pus. Cleaning must be done carefully and patiently.