CLASSIFICATION OF MIDDLE EAR EFFUSIONS BEN
H.
ST.
SENTURIA,
M.D.
LOUIS, MISSOURI
SUMMARY - Proper use of terminology and classification of various categories of effusion throughout the world is necessary if we are to obtain dissemination of pertinent scientific and clinical information and to make progress in understanding and eradicating this widespread group of diseases. The general term, middle ear effusion, and the categories serous, mucoid, and purulent are suggested to describe collections of fluid in the middle ear; the use of other descriptive terms should be influenced by the nature of the clinical, cytologic, bacteriologic, histopathologic and chemical findings in the fluid and lining membrane of the middle ear.
though some of the conclusions drawn, such as the persistent blockage of the Eustachian tube and the ex vacuo concept, are presently bein~ questioned. These observations still form the basis for classification and clinical treatment in many areas of the world. I should like first to emphasize that proper classification of middle ear effusions is a most important prerequisite if we are to continue to make progress with prophylaxis and treatment. We must induce the investigators and the cliniSome degree of confusion exists and cians to examine their patients and the inappropriate treatment is ~ven, in part aspirated fluids with the clear underdue to a failure to clearly communicate standing that the clinical and pathologiwith our fellow investigators and clin- cal changes are different for each of the icians and disseminate the si~icant su~~ested categories of middle ear effuprogress that has been made in classify- sions. Therefore, proper classification requires a complete examination of the in~ the various categories of effusion. To some extent, this is a problem of seman- middle ear, the Eustachian tube, the tics and I should like to direct my at- hearing function, and the cytology bacteriology, and chemistry of the fluid. If tention to this aspect of the problem. we are to benefit from research done in Since any review or analysis of efforts this area, we must urge the investigator to classify middle ear effusions requires to obtain this information and specify a broad examination of etiology, patholo- clearly in his published report what catgy, and treatment, as well as semantics, egories of middle ear effusion he is no effort will be made in this presenta- studying. tion to name the large number of imporThe first point in classification which tant contributors, many of whom are I should like to discuss is the proper participating in this Symposium. term to describe the sum total of all the In the past, a small number of pioneers various fluids which occur in the middle made accurate and detailed anatomical, ear. I would urge that we need to utilize pathological, chemical and clinical ob- a general term like middle ear effusions servations, which are valid today even when we refer to the nondescript ~oup
A careful reading of the recent scientific literature gives clear evidence that we are making progress in our understanding of many of the factors which contribute to the production of middle ear effusions and, consequently, that we are ~ainin~ a better appreciation of their proper classification. Clear scientific evidence is accumulating to help us comprehend the intricate mechanisms which are involved in the etiology, pathogenesis, and treatment of middle ear effusions.
From the Departments of Otolaryngology, Washington University School of Medicine, and The Jewish Hospital of St. Louis, St. Louis, Missouri.
15
16
BEN H. SENTURIA
Fig. 1. Suggested terminology for various stages of middle ear effusions based on cytologic and histopathologic changes in the middle ear.
of effusions, some of which, for example, are of low viscosity and others of high viscosity, some being free of cells while others are saturated with a variety of cells. It would appear desirable, for example, to limit the use of terms such as secretory otitis media and exudative otitis media to specific categories of this complex disease process; in most published papers the former appears to deal with a category in which secretion of the goblet cells and glands is preeminent, and the latter seems to specify a category in which the effusion is accumulated primarily by the escape of fluid, and cells, from the blood vessels. As we review the scientific literature, it becomes increasingly evident that in most middle ear effusions we are dealing with various stages of an inflammatory process and many of the biologic mediators of inflammation may be found in the fluid. As of this time, no one has shown clearly, exactly how this middle ear effusion is triggered. The old concept of subepithelial migration of bacteria up the peritubal lymphatics has not been substantiated. It would appear that contamination of the middle ear occurs through the lumen of the Eustachian tube. Transient obstruction of the lumen of the Eustachian tube, complicated by myriads of neutrophiles and e~foliat.ed tubal epithelium, causes a negative middle ear pressure. There is an associated striking dilatation of. thiJ.1-walled ~ub epithelial vessels (which m ultramicroscopic studies look like veins). and a malfunction (increase in compliance) of a high percentage of the Eustachian tubes. This combination of factors produces an amber cellular-free, low viscosity fluid which 'has all the chemical characteristics of blood serum. It is very widely ac-
cepted that this form of middle ear effusion should be referred to as serous otitis media (Fig. 1). The low viscosity, amber fluids obtained from the middle ears of some of our young patients show some neutrophiles and positive bacterial cultures. I, therefore, suggest we need to add to the classification a seropurulent category. Recently, our finding was confirmed that a high percentage of effusions show positive bacterial cultures and bacterial smears. On the basis of these findings, we clinicians who believe we are practicing superior otology and pediatrics need to remove from our thinking the concept that all middle ear effusions are sterile and begin prescribing antibiotics to control those infections in which positive cultures and smears are obtained. Needless to say, we must not ignore age and immune factors which are involved with changes in local immunoglobulins and lysozymes, as described most recently. Progressive increase in local bacteriostatic activity up to the age of ten years has been demonstrated, so that it is understandable that with the assistance of the immune defense system and antibiotics, the bacteria will be inactivated and a seropurulent fluid will revert to the serous category. Hopefully, the absorptive capacity of the lining membrane of the middle ear and mastoid and the mucociliary mechanism of the tube will remove the residual serous fluid which has accumulated and allow the tympanomastoid system to return to normal. If systemic and local antibacterial immunological activities do not control the infection and effective antibiotics are not prescribed, the purulent phase p~~ dominates and an acute purulent ottt'lS media develops (myriads of neutrophiles medium levels of protein and low levels' of glycoprotein). At this point, spontaneous rupture of the tympanic membrane occurs or myringotomy is performed and the process is aborted. The degree to which effective treatment is provided will determine whether there will occur a normal middle ear or chronic purulent otitis media. In most patients who experience re-
CLASSIFICATION
current purulent otitis media or persistent seropurulent effusions, there will develop a metaplasia of the lining membrane of the middle ear. This includes a large increase in the number of goblet cells and mucous glands which secrete complex proteins (glycoproteins) and a marked inflammatory thickening of the lamina propria showing infiltration with lymphocytes, plasma cells, histiocytes and neutrophiles. Since the effusion produced is composed of mucoid elements which originate in large measure from the epithelium and purulent components arising as a consequence of the inflammation, we chose to call this the mucopurulent catef!.ory. The incidence of positive bacterial cultures and smears is not as high in this category as in serous otitis media; it has been suggested that the immunoglobulins and lysozymes secreted by the epithelium inhibit bacterial growth in these cases. In the mucopurulent category, it is essential that we clinicians keep in mind the need to control whatever infection persists, degrade the complex mucopolysaccharides formed by the mucous secretory cells, remove the persistent viscous secretions from the middle ear, and take whatever action is possible at this time to improve the functional state of the Eustachian tube. These measures will encourage the return of the metaplastic epithelium to its normal nonrespiratory RE;PIUNTS -
17
state and the development of a dry middle ear. Most often the acute and chronic purulent phase and the mucopurulent category are controlled by antibiotics and the local defenses, and the condition changes to a mucoid category in which there remains a hyperfunction of the secretory elements in the epithelium. Therefore, there occurs an insidious and persistent refilling of the middle ear with a viscous glue-like secretion. No comprehensive studies of the mucoid category are available, but those specimens studied reveal that this secretion is free of neutrophiles and does not show positive bacterial cultures. As of this time, we are aware of the slow inactivation of the mucous glands and goblet cells, and we must recognize the need for adequate and prolonged drainage and aeration of the middle ear, during which time the lining membrane will, hopefully, return to a normal, nonrespiratory state. In conclusion, I should like to urge that the participants in this International Symposium give primary consideration to the establishment of a classification of middle ear effusions which will be accepted and utilized throughout the world. By using a common terminology, all workers in this area of research can fully understand and benefit from the careful and thoughtful clinical and fundamental research which is being done by competent investigators everywhere.
Ben H. Senturia, M.D., 4949 Forest Park Blvd., St. Louis, MO 63108.
H.
ST.
SENTURIA,
M.D.
LOUIS, MISSOURI
SUMMARY - Proper use of terminology and classification of various categories of effusion throughout the world is necessary if we are to obtain dissemination of pertinent scientific and clinical information and to make progress in understanding and eradicating this widespread group of diseases. The general term, middle ear effusion, and the categories serous, mucoid, and purulent are suggested to describe collections of fluid in the middle ear; the use of other descriptive terms should be influenced by the nature of the clinical, cytologic, bacteriologic, histopathologic and chemical findings in the fluid and lining membrane of the middle ear.
though some of the conclusions drawn, such as the persistent blockage of the Eustachian tube and the ex vacuo concept, are presently bein~ questioned. These observations still form the basis for classification and clinical treatment in many areas of the world. I should like first to emphasize that proper classification of middle ear effusions is a most important prerequisite if we are to continue to make progress with prophylaxis and treatment. We must induce the investigators and the cliniSome degree of confusion exists and cians to examine their patients and the inappropriate treatment is ~ven, in part aspirated fluids with the clear underdue to a failure to clearly communicate standing that the clinical and pathologiwith our fellow investigators and clin- cal changes are different for each of the icians and disseminate the si~icant su~~ested categories of middle ear effuprogress that has been made in classify- sions. Therefore, proper classification requires a complete examination of the in~ the various categories of effusion. To some extent, this is a problem of seman- middle ear, the Eustachian tube, the tics and I should like to direct my at- hearing function, and the cytology bacteriology, and chemistry of the fluid. If tention to this aspect of the problem. we are to benefit from research done in Since any review or analysis of efforts this area, we must urge the investigator to classify middle ear effusions requires to obtain this information and specify a broad examination of etiology, patholo- clearly in his published report what catgy, and treatment, as well as semantics, egories of middle ear effusion he is no effort will be made in this presenta- studying. tion to name the large number of imporThe first point in classification which tant contributors, many of whom are I should like to discuss is the proper participating in this Symposium. term to describe the sum total of all the In the past, a small number of pioneers various fluids which occur in the middle made accurate and detailed anatomical, ear. I would urge that we need to utilize pathological, chemical and clinical ob- a general term like middle ear effusions servations, which are valid today even when we refer to the nondescript ~oup
A careful reading of the recent scientific literature gives clear evidence that we are making progress in our understanding of many of the factors which contribute to the production of middle ear effusions and, consequently, that we are ~ainin~ a better appreciation of their proper classification. Clear scientific evidence is accumulating to help us comprehend the intricate mechanisms which are involved in the etiology, pathogenesis, and treatment of middle ear effusions.
From the Departments of Otolaryngology, Washington University School of Medicine, and The Jewish Hospital of St. Louis, St. Louis, Missouri.
15
16
BEN H. SENTURIA
Fig. 1. Suggested terminology for various stages of middle ear effusions based on cytologic and histopathologic changes in the middle ear.
of effusions, some of which, for example, are of low viscosity and others of high viscosity, some being free of cells while others are saturated with a variety of cells. It would appear desirable, for example, to limit the use of terms such as secretory otitis media and exudative otitis media to specific categories of this complex disease process; in most published papers the former appears to deal with a category in which secretion of the goblet cells and glands is preeminent, and the latter seems to specify a category in which the effusion is accumulated primarily by the escape of fluid, and cells, from the blood vessels. As we review the scientific literature, it becomes increasingly evident that in most middle ear effusions we are dealing with various stages of an inflammatory process and many of the biologic mediators of inflammation may be found in the fluid. As of this time, no one has shown clearly, exactly how this middle ear effusion is triggered. The old concept of subepithelial migration of bacteria up the peritubal lymphatics has not been substantiated. It would appear that contamination of the middle ear occurs through the lumen of the Eustachian tube. Transient obstruction of the lumen of the Eustachian tube, complicated by myriads of neutrophiles and e~foliat.ed tubal epithelium, causes a negative middle ear pressure. There is an associated striking dilatation of. thiJ.1-walled ~ub epithelial vessels (which m ultramicroscopic studies look like veins). and a malfunction (increase in compliance) of a high percentage of the Eustachian tubes. This combination of factors produces an amber cellular-free, low viscosity fluid which 'has all the chemical characteristics of blood serum. It is very widely ac-
cepted that this form of middle ear effusion should be referred to as serous otitis media (Fig. 1). The low viscosity, amber fluids obtained from the middle ears of some of our young patients show some neutrophiles and positive bacterial cultures. I, therefore, suggest we need to add to the classification a seropurulent category. Recently, our finding was confirmed that a high percentage of effusions show positive bacterial cultures and bacterial smears. On the basis of these findings, we clinicians who believe we are practicing superior otology and pediatrics need to remove from our thinking the concept that all middle ear effusions are sterile and begin prescribing antibiotics to control those infections in which positive cultures and smears are obtained. Needless to say, we must not ignore age and immune factors which are involved with changes in local immunoglobulins and lysozymes, as described most recently. Progressive increase in local bacteriostatic activity up to the age of ten years has been demonstrated, so that it is understandable that with the assistance of the immune defense system and antibiotics, the bacteria will be inactivated and a seropurulent fluid will revert to the serous category. Hopefully, the absorptive capacity of the lining membrane of the middle ear and mastoid and the mucociliary mechanism of the tube will remove the residual serous fluid which has accumulated and allow the tympanomastoid system to return to normal. If systemic and local antibacterial immunological activities do not control the infection and effective antibiotics are not prescribed, the purulent phase p~~ dominates and an acute purulent ottt'lS media develops (myriads of neutrophiles medium levels of protein and low levels' of glycoprotein). At this point, spontaneous rupture of the tympanic membrane occurs or myringotomy is performed and the process is aborted. The degree to which effective treatment is provided will determine whether there will occur a normal middle ear or chronic purulent otitis media. In most patients who experience re-
CLASSIFICATION
current purulent otitis media or persistent seropurulent effusions, there will develop a metaplasia of the lining membrane of the middle ear. This includes a large increase in the number of goblet cells and mucous glands which secrete complex proteins (glycoproteins) and a marked inflammatory thickening of the lamina propria showing infiltration with lymphocytes, plasma cells, histiocytes and neutrophiles. Since the effusion produced is composed of mucoid elements which originate in large measure from the epithelium and purulent components arising as a consequence of the inflammation, we chose to call this the mucopurulent catef!.ory. The incidence of positive bacterial cultures and smears is not as high in this category as in serous otitis media; it has been suggested that the immunoglobulins and lysozymes secreted by the epithelium inhibit bacterial growth in these cases. In the mucopurulent category, it is essential that we clinicians keep in mind the need to control whatever infection persists, degrade the complex mucopolysaccharides formed by the mucous secretory cells, remove the persistent viscous secretions from the middle ear, and take whatever action is possible at this time to improve the functional state of the Eustachian tube. These measures will encourage the return of the metaplastic epithelium to its normal nonrespiratory RE;PIUNTS -
17
state and the development of a dry middle ear. Most often the acute and chronic purulent phase and the mucopurulent category are controlled by antibiotics and the local defenses, and the condition changes to a mucoid category in which there remains a hyperfunction of the secretory elements in the epithelium. Therefore, there occurs an insidious and persistent refilling of the middle ear with a viscous glue-like secretion. No comprehensive studies of the mucoid category are available, but those specimens studied reveal that this secretion is free of neutrophiles and does not show positive bacterial cultures. As of this time, we are aware of the slow inactivation of the mucous glands and goblet cells, and we must recognize the need for adequate and prolonged drainage and aeration of the middle ear, during which time the lining membrane will, hopefully, return to a normal, nonrespiratory state. In conclusion, I should like to urge that the participants in this International Symposium give primary consideration to the establishment of a classification of middle ear effusions which will be accepted and utilized throughout the world. By using a common terminology, all workers in this area of research can fully understand and benefit from the careful and thoughtful clinical and fundamental research which is being done by competent investigators everywhere.
Ben H. Senturia, M.D., 4949 Forest Park Blvd., St. Louis, MO 63108.
