Otitis Media with Effusion
Secretory otitis media, glue ear, serous otitis media, non purulent otitis media.
Otitis media with effusion is defined as chronic accumulation of mucus within the middle ear, and rarely this could involve the mastoid air cell system. This accumulation causes conductive hearing loss.
Histology and histopathology of eustachean tube:
The pseudostratified ciliated columnar epithelium of respiratory tract extends up the eustachean tube as far as the anterior part of the middle ear cavity. These cells are capable of producing mucous. There are also goblet cells seen in their midst. These cells are also capable of secreting mucous material. Otitis media with effusion is caused by inflammation of this epithelium in the eustachean tube and hypotympanum. In established cases of glue ear, the cuboidal epitheliumof middle ear and mastoid air cells gets replaced by thickened pseudostratified columnar epithelium. The cilia of these cells have also been found to be ineffective in propelling the secretions into the nasopharynx. The submucosa is found to be oedematous, inflammed with dilated blood vessels with increased number of macrophages and plasma cells.
Otoscopic picture of Otitis media with effusion
Image showing portions of eustachean tube with respiratory epithelium
1. In many children otitis media with effusion is preceded by an episode of acute otitis media. This is common in children who is more prone for upper respiratory infections. Common being viral infections which damages the eustachean tube epithelium.
2. Craniofacial abnormalities: Children with cleft palate have deficient palatal muscles causing a poor eustachean tube function leading on to Otitis media with effusion. This occurs despite a successful surgical repair of the cleft palate. Children with Down's syndrome are also more prone for OME.
Note: Children with bifid uvula donot appear to have higher incidence of OME
3. Allergy: Previously nasal allergy has been postulated as an important factor in the development of Otitis media with effusion. Studies have been unequivocal.
4. Gastrooesophageal reflux: GERDS has been commonly demonstrated radiologically in children with OME. Furthermore biochemical analysis of middle ear fluid have demonstrated significant amounts of pepsin (in 80% of cases).
5. Parental smoking has been attributed as an important predisposing factor for the development of OME.
Age of occurrence: OME shows classically a bimodal distribution. The first peak occurs around 2 years of age, and the second peak occurs at about 5 years of age. This distribution occurs roughly around the ages when the child goes to preschool and primary school.
Seasonal association: OME commonly occurs during winter season, when there is more likelihood of upper respiratory infections, and also because of the possibility of closer contact with affected children. This is seen in temperate zones. In non temperate zones it is commonly seen during rainy season.
A high index of suspicion is necessary to identify this condition. Every child with upper respiratory infection must be otoscopically examined.
Otoscopic findings: The tympanic membrane may be bulging, or retracted with a distorted cone of light. The ear drum may appear yellow, blue or simply clear white. Pneumatic otoscopy will reveal a ear drum which has a restricted mobility.
Microbiology of OME: Commonly middle ear effusions due to glue ear is sterile. Rarely bacteria could be cultured. The incidence of these pathogens are higher in children under the age of 2, and in children with recurrent upper respiratory infections.
Puretone audiometry: Demonstrates mild to moderate conductive deafness.
Tympanograms (Type B) is commonly associated with OME. Type A is infrequently associated while Type C falls somewhere inbetween. Tympanometry can be used as a screening test to identify patients with OME.
Free field audiometry: Demonstrates deafness.
1. Antibiotics: Amoxycillin is the drug of choice followed by cephalosporins.
2. Nasal decongestants like oxymetazoline / xylometazoline may help in some cases.
3. Topical nasal steroids can be used in resistant cases.
4. Autoinflation of eustachean tube by performing valsalva maneuver. Balloon blowing may also help.
2. Myringotomy and insertion of ventilation tubes