Panel discussion: pathogenesis of otitis media. Pathology and microbiology of otitis media

Otitis media (OM) can be subdivided into purulent, serous, mucoid, and chronic forms. It may occur in the absence of tympanic membrane changes and involve the inner ear. Purulent otitis media is characterized early by edema, hyperemia, and polymorphonuclear leukocyte infiltration in the subepithelial space (SES) and later by mucosal metaplasia, granulation tissue, and osteitis. S. pneumoniae and H. influenza are most commonly identified. Serous and mucoid OM frequently develop from eustachian tube dysfunction. Serous transudate from vessels in the SES passes to the middle ear (serous otitis media). Basal cells differentiate into goblet cells and subepithelial glandular formation occurs. This secretory activity, coupled with fluid reabsorption, results in a mucoid effusion. Bacteria can be cultured from about 30% of these effusions. Chronic otitis media denotes irreversible tissue pathology. It may be sterile although S. aureus and coliform bacteria are frequently isolated.     

Panel discussion: Pathogenesis of otitis media. Bacteriology and immunology

Three features of otitis media with effusion (OME) are important in understanding its pathogenesis: 1. it is most common among children, when the eustachian tube is poorly developed; 2. it is most common during the winter months, when the common cold is prevalent; and 3. bacteria are found in a large number of middle ear effusions from OME patients. Although middle ear effusions are conventionally thought to be sterile, numerous recent investigations favor a bacterial pathogenesis of OME. Four possibilities can be considered: 1. bacteria are modified by antibiotics or antibodies, causing a lingering inflammation; 2. early antibiotic treatment may interfere with the development of local immunity; 3. bacterial antigen trapped in the middle ear causes immune injury leading to OME; and 4. bacterial endotoxin and inflammatory mediators cause middle ear effusions.     

Panel discussion: Pathogenesis of otitis media. Studies on middle ear effusions

The analyses of middle ear effusion (MEE) in otitis media may prove important information for better understanding of etiology, evaluation of inflammatory stages of the middle ear cavity, and evaluation of the efficacy of the treatment. Biochemical composition of serous and mucoid effusion has been characterized in terms of enzymes (lactate dehydrogenase, (LDH), lysozyme, alkaline and acid phosphates), and hexosamine content of MEE. In addition to immunoglobulin (IgA, G, and M) content, several new immunochemical parameters (immune complexes, complements, secretory IgA) and histamines have been determined in various types of MEE. Bacteriological findings of MEE, age of patients, viscosity of MEE, and clinical course (fresh or recurrent) have been correlated with the results of biochemical and immunochemical analyses of MEE. Parallel studies of animal models (serous otitis media by eustachian tube obstruction, purulent otitis media by direct innoculation of pneumococcus) showed sequential changes of mucoperiosteum and alteration of enzyme levels (LDH, lysozyme) at various times after the induction of experimental otitis media. It was found that LDH and lysozyme levels were higher in the purulent otitis media group than in the serous otitis media group and that enzyme levels decreased with clearing of the bacteria along with the resorption of inflammatory changes evidenced by histology. Human MEE studies showed that lysozyme levels were higher in the culture positive group than in the negative group, substantiating the animal findings. Strong indications have been shown that biochemical and immunochemical characteristics of MEE can reflect the degree of inflammatory changes in the middle ear cavity. Thus, baseline information necessary to specify the factors responsible for chronicity or the tendency of recurrence of otitis media has been established. Further longitudinal studies are necessary to evaluate the efficacy of presently available treatment on the management of the disease process in otitis media.     

Current opinions on pathogenesis and treatment of otitis media with effusion in children

Otitis media with effusion (OME) is one of the most often diagnosed diseases in the pre-school children. OME is defined as the presence of effusion behind the intact tympanic memebrane without symptoms of acute infection. Pathogenesis of OME is multifactorial and represents the interactions between environmental, social, anatomical and infectious factors and an allergy. Due to the hearing impairment accompanying this disease, effective prevention and treatment are necessary. This publication presents current knowledge concerning etiopathogenesis of OME taking into consideration the role of Eustachian tube, infectious factor, allergy, immunological factors, NO and gastroesophageal reflux disease. Recommended methods of treatment depending on the clinical condition and the age of children are also presented. The initiation of appropriate therapy is crucial because of the possibility of remote complications.     

Current conservative treatment of childhood chronic secretory otitis media (a survey and discussion)

A questionnaire on medical treatment of childhood secretory otitis was posted to all Consultant Otologists in the Thames Regions of the National Health Service. Questions dealt with indications for medical management, choice of treatment, and indications for omitting medical therapy in favour of immediate surgery, or giving no treatment at all. 86 questionnaires were completed. 81.4 per cent of respondents used medical treatment, but there was no consensus as to the drug or combination preferred. Oral decongestant preparations were the most popular. 87.1 per cent of users of medical therapy sometimes omitted it in favour of immediate surgery, most commonly because previous treatment by another practitioner appeared a failure. 63.1 per cent of all respondents left some cases completely untreated. The views of experienced otologists on the treatment of 'glue ear' vary widely, and there is no acceptable evidence to support any method of medical therapy. Large-scale trials are needed to clarify the position.     

Status of the controversial discussion of the pathogenesis and treatment of chronic otitis media with effusion in childhood

BACKGROUND: Chronic otitis media with effusion is one of the most common diseases in childhood. The causes of otitis media are unclear as far as their importance is concerned. METHOD: Extensive search in the German and Anglo-saxon literature with following presentation of the results. RESULTS: The original idea of a mechanical obstruction of the eustachian tube by the adenoids seems to be insufficient. Inflammatory mechanisms as a result of pathogenic germs in the middle ear fluid stand opposite to immunomodulating mechanisms as relevant causes of chronic otitis media with effusion. There are references which lead to the importance of allergic co-mechanisms individually. The controversial discussion of the pathophysiology of chronic otitis media with effusion is illustrated by the different opinions of optimal treatment modalities. Varying medical treatment opportunities exist while centrally the importance of the use of antibiotics is controversial. Based on the absence of long lasting effects of medical treatments, there are groups supporting a wait-and-see policy. Concerning the long-term effects of operative treatment, the importance of isolate tubes insertion in opposition to a combined treatment modality (adenotomy and tubes) is controversial. The actual debate focusses on adenotomy or adenotonsillectomy without operating the middle ear as treatment modality in patients with otitis media with effusion. CONCLUSIONS: Economic and social importance of this disease forces further investigations in pathogenesis and optimizing of medical and operative treatment modalities.     

Pathogenesis and treatment of chronic purulent otitis media and its complications: immunological aspects

Clinicoimmunological, microbiological and cytological examinations were made in 96 patients with otitis media purulenta chronica (OMPC) and otogenic intracranial complications. It was found that in different clinical forms of OMPC nonspecific defense and immunity indices vary. In OMPC and chronic purulent mesotympanitis the indices change insignificantly. In chronic purulent epitympanitis and otogenic intracranial complications there was suppression in T-cell immunity and nonspecific defense. Middle ear secretion contained less SIgA and lysozyme, blood contained more amount of IgA and IgM and less of IgG. Deficiency of general and local defense antiinfectious mechanisms shows significance of immune and nonspecific resistance in transformation of ear inflammation into chronic phase and development of complications. Alterations in immunity, nonspecific defense and tympanic cavity depend on the causative agent of OMPC. Association of St. aureus with gramnegative flora or anaerobic infection cause the greatest immune deficiency. Temporal bone surgery and standard treatment for 21 days fail to eradicate initial immune disorders in the blood and middle ear. Thymalin immunocorrection improves nonspecific defense and immunity, attenuates inflammation and stimulates reparative processes in the trepanation wound of the ear.     

Intractable otitis media - Pathogenesis and treatment of Eosinophilic otitis media (EOM) and otitis media with Antineutrophil cytoplasmic antibody (ANCA) -associated vasculitis (OMAAV)

Intractable otitis media is resistant to antimicrobial therapy, tympanostomy ventilation tube insertion, and surgery. In children, intractable acute otitis media, pathological tympanic membrane due to prolonged otitis media with effusion (OME), tympanic membrane atelectasis, and adhesive otitis media are common. Contrarily, in adults, otitis media caused by drug-resistant pathogens, tuberculous otitis media, cholesterol granuloma, malignant otitis externa (skull base osteomyelitis), eosinophilic otitis media (EOM), and otitis media with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (OMAAV) are common and require differentiation. Among them, EOM is increasing along with eosinophilic upper respiratory tract diseases, such as bronchial asthma and eosinophilic chronic rhinosinusitis (ECRS), a subgroup of chronic rhinosinusitis with nasal polyps (CRSwNP). EOM is associated with adult-onset bronchial asthma and is characterized by viscous middle ear effusion and middle ear mucosa thickness with eosinophilic infiltration, which requires treatment with glucocorticoids according to disease activity and symptoms. Recently, OMAAV was proposed because of the similarities in clinical features and therapeutic effects. The clinical course of OMAAV is characterized by a relatively rapid increase in the bone conductive hearing threshold, which progresses over 1-2 months, without response to antimicrobial agents or tympanostomy ventilation tube insertion, and in some cases, is complicated by facial paralysis and hypertrophic pachymeningitis. This new concept may explain the pathogenesis and clinical presentation of many cases of intractable otitis media, the cause of which was previously unknown. Although making a diagnosis of OMAAV is relatively easy based on the clinical course, such as vascular dilatation of the tympanic membrane and positive ANCA titer, it is often difficult because the ANCA titer becomes negative with previous administration of glucocorticoids. In adults with intractable otitis media, ANCA titers must be measured before glucocorticoid administration. Treatment consisted of remission induction therapy with a combination of glucocorticoids and immunosuppressive drugs.     

从一个病例分析中耳炎治疗的有关问题

中耳炎是一种常见病多发病，严重影响人类的健康，正确有效地治疗中耳炎是耳科学的重要课题，作者试图通过对1例中耳炎病例的治疗经过来分析中耳炎治疗的有关问题。     

Secretory otitis media. Aspects on treatment and control.

In a double-blind study, 228 secretory otitis media patients were evaluated according to mucolytic and decongestive treatment. No definite difference comparing with the placebo group was registered. About 50% of all patients were cured within 4 weeks after the diagnosis was established. Those patients who earlier had been treated with antibiotics because of a preceding acute otitis media had a better cure rate than the untreated group. Suggestions on treatment and control of secretory otitis media are given.     

Current antibacterial therapy of acute otitis media

General approaches to general and local therapy of acute otitis media are validated and schemes of antibacterial treatment of this disease are proposed.