Basic Otorhinolaryngology E-Book

Rudolf Probst

• Herausgeber: Thieme
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 952

Veröffentlichungsjahr: 2017

Beschreibung

Basic Otorhinolaryngology: A Step-by-Step Learning Guide, Second Edition, is an accessible introduction to the core concepts and potentially complex interrelationships in otorhinolaryngology and head and neck surgery. The fully revised new edition includes latest developments and up-to-date terminology, up-to-date diagnostic and treatment methods, and succinct overviews of important international consensus documents and position papers in the field. The book presents material in an engaging and user-friendly format, with chapters divided into study units that follow a consistent structure. Readers will also find a wealth of figures, tables, and flowcharts to facilitate quick comprehension of topics.

Key Features:

• Completely updated chapters on audiology and vestibular disorders
• New or expanded discussion of olfactory mucosa and disturbances, obstructive sleep apnea syndrome, imaging methods, immunotherapy for allergic rhinitis, Aspergillus sinusitis, ear canal cholesteatoma, peripheral nerve paralysis, and much more
• More than 600 superb full-color photographs, illustrations, and diagrams-many new or improved for this edition-clarify anatomical, operative, and embryological concepts
• Chapters organized into brief study units make learning the material manageable and convenient
• Each study unit begins with a starter outlining objectives for the unit and its relationship to other units and the overall scheme
• Numerous cross-references to other study units enable rapid navigation to relevant areas
• "Knowledge in depth" boxes provide information that goes beyond a basic understanding, such as surgical techniques, historical details, and case examples
• "Points of emphasis" throughout call direct attention to the most pertinent facts

Basic Otorhinolaryngology: A Step-by-Step Learning Guide, Second Edition, is an ess

Leseprobe

Basic Otorhinolaryngology

A Step-by-Step Learning Guide

2nd Edition

Rudolf Probst, MD

Professor and formerly DirectorDepartment of Otolaryngology –Head & Neck SurgeryUniversity Hospital ZurichZurich, Switzerland

Gerhard Grevers, MD

ProfessorPrivate PracticeStarnberg, Germany

Heinrich Iro, MD

Professor and DirectorDepartment of Otolaryngology –Head & Neck SurgeryUniversity Hospital ErlangenErlangen, Germany

With contributions by

Frank WaldfahrerFrank RosanowskiUlrich Eysholdt

635 illustrations

ThiemeStuttgart • New York • Delhi • Rio de Janeiro

Library of Congress Cataloging-in-Publication Data is available from the publisher.

Illustrator: Karin Baum, Paphos, Cyprus

3rd German edition 20081st Greek edition 20061st Russian edition 20111st Turkish edition 2010

© 2006, 2018 by Georg Thieme Verlag KG

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ISBN 978-3-13-132442-9

Also available as an e-book:eISBN 978-3-13-203472-3

Important note: Medicine is an ever-changing science undergoing continual development. Research and clinical experience are continually expanding our knowledge, in particular our knowledge of proper treatment and drug therapy. Insofar as this book mentions any dosage or application, readers may rest assured that the authors, editors, and publishers have made every effort to ensure that such references are in accordance with the state of knowledge at the time of production of the book.

Nevertheless, this does not involve, imply, or express any guarantee or responsibility on the part of the publishers in respect to any dosage instructions and forms of applications stated in the book. Every user is requested to examine carefully the manufacturers’ leaflets accompanying each drug and to check, if necessary in consultation with a physician or specialist, whether the dosage schedules mentioned therein or the contraindications stated by the manufacturers differ from the statements made in the present book. Such examination is particularly important with drugs that are either rarely used or have been newly released on the market. Every dosage schedule or every form of application used is entirely at the user's own risk and responsibility. The authors and publishers request every user to report to the publishers any discrepancies or inaccuracies noticed. If errors in this work are found after publication, errata will be posted at www.thieme.com on the product description page.

Some of the product names, patents, and registered designs referred to in this book are in fact registered trademarks or proprietary names even though specific reference to this fact is not always made in the text. Therefore, the appearance of a name without designation as proprietary is not to be construed as a representation by the publisher that it is in the public domain.

This book, including all parts thereof, is legally protected by copyright. Any use, exploitation, or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to prosecution. This applies in particular to photostat reproduction, copying, mimeographing, preparation of microfilms, and electronic data processing and storage.

Contents

Preface

Contributors

INose, Paranasal Sinuses, and Face

1 Anatomy, Physiology, and Immunology of the Nose, Paranasal Sinuses, and Face

Gerhard Grevers

2 Diagnostic Evaluation of the Nose and Paranasal Sinuses

Gerhard Grevers

3 Diseases of the Nose, Paranasal Sinuses, and Face

Gerhard Grevers

IIOral Cavity and Pharynx

4 Lips and Oral Cavity

Gerhard Grevers

5 Pharynx and Esophagus

Gerhard Grevers

6 The Salivary Glands

Heinrich Iro, Frank Waldfahrer, Rudolf Probst

IIIEar

7 Anatomy and Physiology of the Ear

Rudolf Probst

8 Audiology (Auditory Testing)

Rudolf Probst

9 Hearing Disorders in Children—Pediatric Audiology

Rudolf Probst

10 The External Ear

Rudolf Probst

11 The Middle Ear

Rudolf Probst

12 Inner Ear and Retrocochlear Disorders

Rudolf Probst

13 Vestibular Disorders

Rudolf Probst

14 Facial Nerve

Rudolf Probst

15 Lateral Skull Base

Rudolf Probst

IVNeck

16 External Neck

Heinrich Iro, Frank Waldfahrer

17 Larynx and Trachea

Heinrich Iro, Frank Waldfahrer

18 Voice Disorders

Frank Rosanowski, Ulrich Eysholdt

19 Speech and Language Disorders

Frank Rosanowski, Ulrich Eysholdt

Appendix

Emergencies and Primary Measures

Heinrich Iro, Frank Waldfahrer

Sources

Index

Preface

This preface aims to provide you with some background information on this textbook: Who can benefit most from this book? What is the teaching approach that is used—i.e., how are the contents presented to make them easier to learn? Who are the members of the “textbook team”? What is new in this completely revised second edition?

Approach

Who is the book written for? The classic textbook still has its value, particularly when a new subject area is introduced for learning and basic material is presented. This book is primarily intended for students exposed to otorhinolaryngology, but it is also written for physicians, especially those taking part in further training and looking for basic information.

True learning means understanding, and so teaching means explaining. An essential part of learning is the understanding of basic concepts and potentially complex interrelationships. Moreover, learning should be interesting, and it should convey enjoyment of the material and its fascinating aspects. In this sense, this book aspires to be more than an exam review or a quick reference to specific questions. It was our goal to create an educationally compelling, graphically attractive, yet affordable textbook.

Structure: One of the main goals was to present the material in an easy-to-learn, user-friendly format. The result is a textbook in which the material is broken down into brief study units () representing cohesive learning units. Subdividing the contents into manageable portions makes it possible to present thematic highlights that would have been more difficult to incorporate into chapters with a traditional structure.

Each study unit begins with a starter in boldface type. This states the topics that are covered in the unit and the way in which they fit into the overall scheme. Special points are noted, and the material is related to other study units. The starter is not a summary.

The topics in each study unit are presented on facing pages. For clarity, “open-book” logos are shown at the bottom corner of the right-hand page: the number of logos (from one to six) indicates the number of facingpage sets that are contained in the current study unit. The red-colored logo shows where you are in the unit.

Subject matter: This textbook conforms to the latest developments in otorhinolaryngology and head and neck surgery. All main information that is needed for the basic understanding of a topic is contained in the main text, figures, and tables.

1 Knowledge in depth

Boxes marked with this symbol provide information that goes beyond a basic understanding. This may include operating techniques, illustrative case descriptions, historical information, or repetitions from earlier study (e.g., in embryology). If you are in a hurry, you can skip the in-depth boxes and still understand the material in the main text.

Points of emphasis are meant to indicate “caution” or “take note,” and serve to direct attention to key points.

Terminology: Efforts have been made in various areas of otorhinolaryngology to establish a standard international nomenclature. The most up-to-date terms are used in the current text, while older or less commonly used terms are noted as synonyms.

Fig. 1 Color code for flowcharts

Acknowledgments

We are excited about our continued collaboration on this book, which first appeared in German in the year 2000. The current second edition of the English version has been completely revised. Both the text and the illustrations have been substantially changed in many chapters, reflecting the many—and sometimes fundamental—advances in otorhinolaryngology since the first English edition was published in 2006. The same team of authors has worked on the current edition, and our continued collaboration has resulted in a text that is greater than the sum of the authors’ individual contributions. Anne Lamparter and Martina Habeck, our project managers at Thieme Publishers for the second English edition, have made substantial contributions to this outcome through their enthusiasm and commitment. Stephan Konnry at Thieme Publishers has been the Executive Editor for the English version from the beginning of this project. He continues to contribute his skill and experience to this book, keeping in mind all the cultural aspects associated with a foreign language edition. We are also grateful to the publishers, Thieme, for promoting the project and fostering its development. Finally, our thanks go to Karin Baum for her skillful artwork and her significant additions to the new edition.

Special gratitude is owed to our families. A great deal of time that should really have belonged to them was spent preparing this project. Even so, they supported our lengthy work on the book with the encouragement that only a family can provide.

What Can We Improve?

Our goal was to tailor this book to meet our readers’ needs. Only you, the reader, can judge whether we have accomplished this aim. We would therefore be delighted for you to contact us or the publishers regarding any changes that you would like to see in the next edition. We wish you much enjoyment and every success with this book.

Rudolf Probst, MDGerhard Grevers, MDHeinrich Iro, MD

Contributors

Ulrich Eysholdt, MD, PhDProfessorDepartment of Medical Physics and AcousticsUniversity of OldenburgOldenburg, Germany

Frank Rosanowski, MDProfessorPrivate PracticeNuremberg, Germany

Frank Waldfahrer, MDDepartment of Otolaryngology – Head & Neck SurgeryUniversity Hospital ErlangenErlangen, Germany

I Nose, Paranasal Sinuses, and Face

1 Anatomy, Physiology, and Immunology of the Nose, Paranasal Sinuses, and Face

2 Diagnostic Evaluation of the Nose and Paranasal Sinuses

3 Diseases of the Nose, Paranasal Sinuses, and Face

1 Anatomy, Physiology, and Immunology of the Nose, Paranasal Sinuses, and Face

1.1 Basic Anatomy of the Nose, Paranasal Sinuses, and Face

The shape and appearance of the external nose affect not only the overall appearance of the face, but also the functional processes that take place inside the nose. The structural anatomy of the nose is important for both aesthetic and functional reasons, since the nose, as the gateway to the respiratory tract, performs a variety of physiologic functions.

Facial Skin and Soft Tissues

For the effective surgical treatment of soft-tissue defects in the face, whether of a traumatic or neoplastic nature, it is important to consider some distinctive features of the morphology and topographic anatomy of the face, since this is a highly conspicuous region in which the faulty or inadequate treatment of tissue changes will have obvious consequences. One such feature involves the tension lines of the skin (Fig. 1.1a), known also as the relaxed skin tension lines. Scars can be made less conspicuous by taking these tension lines into account when suturing facial skin injuries. The aesthetic units of the face are an important consideration in the treatment of larger soft-tissue defects (Fig. 1.1b). Failure to take these units into account will produce a poor cosmetic result.

The Facial Skeleton

Knowing the various components of the bony facial skeleton (Fig. 1.2) and their relationship to one another is important in trauma management and also in the diagnosis and treatment of inflammatory diseases of the facial skeleton and their complications. The upper jaw bone, or maxilla, houses the maxillary sinus and articulates laterally with the zygomatic bone (zygoma) via the zygomatic process (Fig. 1.2). The upper part of the maxilla borders the nasal bone, and its frontal process projects upward to the frontal bone. The zygoma also has a frontal process that connects superiorly with the frontal bone lateral to the orbit. The zygoma communicates posteriorly with the zygomatic arch.

External Nose

The shape of the external nose is defined by the nasal bones, a pair of rectangular bones in the upper nasal dorsum, and by the paired lateral cartilages (upper nasal cartilages) and alar cartilages (major alar cartilages) in the central and lower portions of the nose (Fig. 1.3). The lateral portions of the nasal alae also contain several small accessory cartilages, called the minor alar cartilages, which are embedded in the lateral soft tissues of the nose.

The shape and stability of the alar cartilages, each of which consists of a medial and lateral crus, chiefly determine the appearance of the nasal tip and the shape of the nares. As a result, they are also important in maintaining an effective nasal airway. Besides the medial crura, the inferior septal margin and the connective-tissue septum (columella) are also responsible for stabilizing the base of the nose (Fig. 1.4a). Subluxation of the inferior septal margin can also hamper nasal breathing by partially obstructing the nasal airway (Fig. 1.4b).

Fig. 1.1 Skin tension lines and aesthetic units The incisions in facial operations should be placed along skin tension lines (a) whenever possible. The aesthetic units (b) should be considered in the closure of soft-tissue defects to achieve a satisfactory cosmetic result.

Fig. 1.2 The cranial bones The diagram shows the cranial bones that are relevant to rhinologic disorders.

Fig. 1.3 Structure of the external nose Various bony and cartilaginous structures define the appearance of the external nose.

Fig. 1.4 Anatomy of the nasal basea The anatomically important cartilaginous structures are projected onto the nasal base. b The nasal septum is subluxed toward the left side, partially obstructing the nasal airway.

Nasal Cavities

The nasal cavities begin anteriorly at the nasal vestibule, which is bordered posteriorly by the internal nasal valve (limen nasi) located between the posterior border of the alar cartilage and the anterior border of the lateral cartilage. This valve area is the narrowest portion of the upper respiratory tract and, as such, has a major bearing on the aerodynamics of nasal airflow (see also 1.3). The anterior bony opening of the nasal cavity, called the piriform aperture, is bounded laterally and inferiorly by the maxilla and superiorly by the nasal bone (see Fig. 1.2). The interior of the nose behind the nasal valve is divided by the nasal septum into two main cavities. The nasal septum is composed of an anterior cartilaginous part and two posterior bony parts. Abnormalities in the shape of the nasal septum (see also 3.2, Septal Deviation), which may consist of a deviated septum, tension septum, spurs, or ridges, are a frequent cause of nasal airway obstruction. The choanae are the paired posterior openings through which the nasal cavities communicate with the nasopharynx.

The nasal cavity is bounded laterally by the lateral nasal walls, which are formed by the ethmoid bone and maxilla, and posteriorly by the palatine bone and the pterygoid process of the sphenoid bone. Several functionally important structures are located on the lateral nasal wall: the nasal turbinates and their associated passages (meati), sinus ostia, and the orifice of the nasolacrimal duct (Fig. 1.5).

Fig. 1.5 Structure of the lateral nasal wall The relationship of the middle meatus to the sinus ostia is of special importance. See also 1.3, Anatomy of the Ostiomeatal Unit.

The inferior turbinate consists of a separate bone that is attached to the medial wall of the maxillary sinus. The opening of the nasolacrimal duct is located in the corresponding inferior meatus (1.1). The middle and superior turbinates are part of the ethmoid bone. In rare cases, a rudimentary “supreme turbinate” is also present above the superior turbinate.

The middle turbinate has by far the greatest functional importance, because most of the drainage tracts from the surrounding paranasal sinuses open into the middle meatus (see also 1.3, Anatomy of the Ostiomeatal Unit).

The nasal cavity is bounded superiorly by the cribriform plate of the ethmoid bone. This thin bony plate has numerous openings for the passage of the fila olfactoria and also forms the boundary of the anterior cranial fossa. The floor of the nasal cavity is formed mostly by the hard palate, which is formed in turn by the two palatine processes of the maxilla and the horizontal laminae of the palatine bone.

Paranasal Sinuses

The paranasal sinuses are air-filled cavities that communicate with the nasal cavities (Fig. 1.6). All but the sphenoid sinus are already present as outpouchings of the mucosa during embryonic life, but except for the ethmoid air cells, they do not develop into bony cavities until after birth. The frontal sinus and sphenoid sinus reach their definitive size in the first decade of life. The maxillary sinus is present at birth but remains very small until the second dentition, because the presence of tooth germs in the maxilla limits the extent of the sinuses. The maxillary sinus, frontal sinus, and anterior ethmoid cells drain into the nasal cavity through the middle meatus—i.e., below the middle turbinate (Fig. 1.5). The posterior ethmoid cells drain into the nasal cavity through the superior meatus. The ostium of the sphenoid sinus is located in the anterior wall directly above the choanae. The anatomic connections between the nasal cavity and paranasal sinuses are functionally important and play a key role in the pathogenesis of many rhinologic diseases that involve the paranasal sinuses (see also 1.3, Anatomy of the Ostiomeatal Unit).

1.1 Nasolacrimal duct

The nasolacrimal duct is part of the lacrimal apparatus, which also includes the lacrimal gland, the lacrimal ducts, and the lacrimal sac. It runs in a bony canal between the medial canthus of the eye and the inferior nasal meatus.

Fig. 1.6 Paranasal sinuses Diagram of the sinuses projected onto the cranial surface.

1.2 Ethmoid roof and cribriform plate

The roof of the ethmoid labyrinth is formed mainly by the portion of the frontal bone that covers and closes the ethmoid cells superiorly. The ethmoid roof is continuous medially with the cribriform plate, the lateral lamina of which represents the continuation of the attachment of the middle turbinate and is very easily injured during surgical manipulations in this region (Fig. 1.7). The levels of the ethmoid roof and cribriform plate can vary considerably, even in the same patient, depending on the vertical extent of the lateral lamina. Computed tomography scans should be taken preoperatively to define the individual anatomy of the anterior skull base region (Fig. 1.8).

Fig. 1.7 Ethmoid roof and anterior ethmoid at the level of the crista galli

Fig. 1.8 Computed tomography (consecutive coronal scans) in a patient with recurrent nasal polyps

The maxillary sinus borders the nasal cavity laterally, and the orbital floor separates the upper part of the sinus from the orbit. Behind the maxillary sinus is the pterygopalatine fossa, which is traversed by the maxillary artery along with branches of the trigeminal nerve and autonomic nervous system. The floor of the maxillary sinus is closely related to the roots of the second premolar and first molar teeth. This creates a potential route for the spread of dentogenic infections, and a tooth extraction may create a communication between the oral cavity and maxillary sinus (oroantral fistula).

Superior and medial to the maxillary sinus are the ethmoid air cells—a labyrinthine system of small, pneumatized sinus cavities that are separated from one another by thin bony walls and extend posteriorly between the middle turbinate (medial border) and orbit to the sphenoid sinus. The orbital plate of the ethmoid bone, also called the lamina papyracea, forms the lateral bony wall that separates the ethmoid air cells from the orbit. Paranasal sinus inflammations can spread through this lamina to involve the orbit (orbital complications). The posterior ethmoid cells are closely related to the optic nerve. The ethmoid roof and cribriform plate (1.2) form the bony boundary that separates the ethmoid cells from the anterior cranial fossa. The surgeon who operates in this region must have a detailed knowledge of the relations of these structures to the ethmoid labyrinth. The sphenoid sinus is located at the approximate center of the skull above the nasopharynx. Its posterior wall is formed by the clivus. It relates laterally to the cavernous sinus, the internal carotid artery, and cranial nerves II to VI, and it is very closely related to the optic canal.

The optic nerve and internal carotid artery may run directly beneath the mucosa of the lateral wall of the sphenoid sinus, without a bony covering.

The sphenoid sinus is bordered superiorly by the sella turcica and pituitary and by the anterior and middle cranial fossae.

The frontal sinus is located in the frontal bone, its floor forming the medial portion of the orbital roof. The sinus, which is highly variable in its extent, is bounded behind by the anterior cranial fossa. Inflammations of the frontal sinus can give rise to serious complications because of its close proximity to the orbit and cranial cavity (orbital cellulitis, epidural or subdural abscess, meningitis).

Vascular Supply

The external nose derives most of its blood supply from the facial artery, which arises from the external carotid artery, and from the ophthalmic artery, which springs from the internal carotid artery. The internal nose receives blood from the territories of the external and internal carotid arteries: the terminal branches of the sphenopalatine artery, which arises from the maxillary artery, and the anterior and posterior ethmoid arteries, which arise from the ophthalmic artery. A detailed knowledge of the vascular supply is particularly important in the management of intractable epistaxis (nosebleed), which requires vascular ligation or angiographic embolization as a last recourse (see also 3.3, Treatment). The venous drainage of the facial region is handled by the facial vein, retromandibular vein, and internal jugular vein. The regional lymphatic drainage of the face and external nose is handled mainly by the submandibular lymph nodes, while the nasal cavity is additionally drained by the retropharyngeal and deep cervical lymph nodes.

Nerve Supply

The facial skin receives its sensory innervation from terminal branches of the trigeminal nerve that enter the facial region through the supraorbital, infraorbital, and mental foramina (see Fig. 1.2). Only the skin over the mandibular angle and the lower portions of the auricle are supplied by the great auricular nerve. The facial muscles are classified as mimetic or masticatory, each of these groups receiving different motor innervation. While the mimetic muscles of the face develop from the blastema of the second branchial arch (the hyoid arch) and accordingly are supplied by the facial nerve, the masticatory muscles trace their embryonic development to the first branchial arch (the mandibular arch) and are therefore supplied by mandibular nerve branches arising from the trigeminal nerve.

1.3 Anatomy of the ostiomeatal unit

The term ostiomeatal unit describes the area on the lateral nasal wall where the ostia of the paranasal sinuses (except for the sphenoid sinus) open into the nasal cavity in a ductlike fashion. Even minor changes (e.g., anatomic variants, mucosal swelling) can hamper ventilation in this region, leading to pathologic sequelae in the paranasal sinuses (see below). The functionally significant anatomic structures of the ostiomeatal unit are the uncinate process, the semilunar hiatus, the frontal recess, the ethmoid bulla, the ethmoid infundibulum, and the maxillary sinus ostium (a coronal section is shown in Fig. 1.9). The frontal sinus is connected to the ostiomeatal unit via the frontal recess, which has an hourglasslike shape. The uncinate process is a thin fibrous or bony process on the lateral nasal wall that arises slightly behind the anterior border of the middle turbinate and may narrow the passage from the nasal cavity to the ostiomeatal complex, depending on its degree of development. Located between the posterior border of the uncinate process and the first ethmoid cell (the ethmoid bulla) is another slitlike passage within the ostiomeatal complex, known as the semilunar hiatus. The space between the uncinate process, ethmoid bulla, and lamina papyracea of the ethmoid bone is called the ethmoid infundibulum. The ostiomeatal unit is bounded medially (toward the nasal cavity) by the middle turbinate and laterally by the lamina papyracea.

The main clinical significance of this region relates to the sites of narrowing in the ostiomeatal unit. For example, hyperemia and swelling of the mucosa in the setting of a common cold can obstruct the narrow passages in the ostiomeatal unit, preventing adequate ventilation of the dependent paranasal sinus system and setting the stage for a rhinogenic inflammation of the paranasal sinuses (sinusitis).

Fig. 1.9 Anatomy of the ostiomeatal unit

Functional Anatomy of the Ostiomeatal Unit

The nose and paranasal sinuses are regarded as a functional unit. Many rhinologic disorders are transmitted from the nasal cavity into the paranasal sinus system. The ostiomeatal unit is the collective term for various anatomic structures located about the middle meatus. It represents the region on the lateral nasal wall that receives drainage from the anterior ethmoid cells, frontal sinus, and maxillary sinus (1.3). It is important to know the anatomic details of this region to understand the pathophysiology of acute and especially chronic paranasal sinus inflammations and the surgical procedures that are used in the causal treatment of these conditions.

1.2 Morphology of the Nasal Mucosa

Besides the anatomic structure of the external nose and nasal cavity, the nasal mucosa plays an essential role in numerous functions of the nose owing to its “gateway” location in the respiratory tract (see also 1.3, Basic Physiology and Immunology of the Nose). This deals with the morphologic structure of the nasal mucosa. Understanding this structure is necessary for an understanding of functional processes.

The anterior part of the nasal cavity (the nasal vestibule), like the external nose, is covered by skin composed of a multilayer, keratinizing squamous epithelium. Anterior to the head of the inferior turbinate, this keratinized epithelium gives way to a nonkeratinized squamous epithelium, a nonciliated columnar epithelium, and finally a ciliated respiratory epithelium. Along with the submucous tissue, this ciliated epithelium forms the typical mucosal lining of the nasal cavity and paranasal sinuses (Fig. 1.10). A small area on the upper nasal septum, superior turbinate, and part of the middle turbinate, located adjacent to the cribriform plate, is covered by olfactory mucosa and is called the olfactory region.

Respiratory Mucosa

Epithelium

The epithelium of the respiratory mucosa is composed of ciliary cells, goblet cells, and basal cells and provides an initial, mechanical barrier against infection. The ciliary cells dominate the surface of the respiratory epithelium. Each ciliary cell has about 150 to 200 cilia, which are composed of microtubules and are interlinked by “dynein arms.” This cytoskeleton of the ciliary cells and the activity of dynein, a specialized protein, enable the typical, synchronous beating of the cilia in the respiratory epithelium. This ciliary action propels a blanket of mucous secretions (from the goblet cells) and serous secretions (from the nasal glands) toward the nasopharynx, mechanically cleansing the inspired air in a mechanism called mucociliary transport (see also 1.3, Basic Physiology and Immunology of the Nose). The basal cells represent the morphologic connection between the columnar epithelium and goblet cells on the one hand and the epithelial basement membrane on the other. They are distinguished from the other epithelial cell types by an increased expression of certain adhesion molecules (e.g., intracellular adhesion molecule-1, ICAM-1) and increased cytokine synthesis (e.g., interleukin 1). Besides the four cell types mentioned, the epithelium also contains immunocompetent cells, mostly CD8-positive T cells, along with smaller numbers of mast cells, macrophages, and MHC-II-bearing dendritic cells, which function as antigen-presenting cells.

Lamina Propria

The lamina propria of the nasal mucosa is separated from the epithelium by a basement membrane. Some areas of the lamina propria, especially about the inferior turbinate, show a marked preponderance of vascular structures known as venous erectile tissue or sinusoids. They consist of thin-walled and thick-walled venous capacitance vessels, which are important not only in warming the inspired air and producing secretions but also in controlling the tumescence of the nasal mucosa. Besides the venous capacitance vessels, there are capillaries and, in deeper areas, arterial vessels. The lamina propria also contains numerous nasal glands, which mainly produce a serous secretion. The immunocompetent cells in the lamina propria consist of CD4-positive T lymphocytes along with CD8-positive cytotoxic cells and suppressor cells such as CD4-/CD8-negative T lymphocytes, mature B lymphocytes, Ig-plasma cells, mast cells, and macrophages. These cellular elements demonstrate the importance of the nasal mucosa, which acts in concert with local host reactions to mediate inflammatory and allergic responses in the nose (see also 1.3, Basic Physiology and Immunology of the Nose).

Fig. 1.10 Respiratory nasal mucosaa Structure of the lamina propria in histologic section. b Scanning electron micrograph of cilia and microvilli.

Nerve Supply

Finally, the nasal mucosa is endowed with a rich nerve supply. It receives its sensory innervation from the trigeminal nerve and its autonomic innervation from the pterygopalatine ganglion. The parasympathetic fibers of this ganglion induce vasodilation and stimulate the secretory activity of the nasal glands, while the sympathetic fibers produce vasoconstriction and inhibit glandular secretion. In addition, nitric oxide (NO) influences neurotransmission and neuromodulation of nasal blood vessels and glands of the nasal mucosa.

Olfactory Mucosa

Topography: The olfactory mucosa (see 1.4 for details on structure and function) covers the olfactory region, which occupies the anterosuperior part of the nasal septum and adjacent areas of the lateral nasal wall, including the side of the superior turbinate facing the septum and part of the middle turbinate. The olfactory mucosa has the capability to regenerate lifelong. The junction of the olfactory mucosa with the respiratory mucosa is variable in its location.

Stimulus processing system: Although it covers an area of only a few square centimeters, the olfactory mucosa contains between 12 and 30 million olfactory receptor neurons (ORN). These ORN are bipolar sensory cells and have dendritic epithelial processes, which protrude into the mucus layer and possess up to 20 cilia with integrated receptor proteins (see also 1.3, Olfaction). The ORN also have basal axons that pass through the basement membrane between the supporting cells (sustentacular cells) and basal cells and then join into bundles that are encompassed by olfactory ensheathing cells of Schwann's cells’ or astrocytes’ character. These axon bundles, called the fila olfactoria, pass through foramina in the cribriform plate of the ethmoid bone and enter the cranial cavity. There they unite to form the olfactory nerve and pass to the olfactory bulb in the brain, the primary olfactory center. The latter is connected via the olfactory tract to the secondary olfactory center in the temporobasal cortex, which is responsible for the perception of smells and their association with other sensory impressions. The secondary olfactory center also has projections to the limbic system that connect with the autonomic centers in the thalamus and hypothalamus; this creates a pathway that mediates the emotional and affective phenomena that are associated with smells. The olfactory cortex has connections with the tertiary olfactory centers (including the hippocampus, anterior insular region, and reticular formation), which are believed to have polysensory associative functions.

1.4 Olfactory mucosa

Microscopic anatomy: Besides olfactory receptor cells (ORN), the epithelium of the olfactory mucosa is composed of microvilli, supporting cells, and basal cells (mainly of the globose type, globose basal cells). The lamina propria additionally contains serous glands (olfactory glands) and vessels. The function of the microvilli and of the olfactory glands located in the lamina propria of the olfactory mucosa is not yet fully understood.

The microvilli most likely represent extra chemoreceptors in the olfactory epithelium, which perform their function along with the classic receptor cells.

As for the olfactory glands, it is assumed that the secretions from these glands, released at the surface of the epithelium, also play a role in mediating the olfactory sense. Recent studies have shown that the secretion layer on the epithelium contains a specific protein that has a high affinity for most odorous substances, and thus could facilitate or even mediate their binding to the sensory cells.

1.3 Basic Physiology and Immunology of the Nose

To understand the pathologic processes that are important in inflammatory and allergic diseases of the nose, it is necessary to first understand the physiologic functions. As the threshold of the respiratory tract in humans, the nose is of major importance in conditioning the air before it reaches the lower airways. To understand this complex process, we must know something about the physics of nasal airflow, which also affects the warming and humidification of the inspired air. Due to its exposed position, the nasal mucosa is in constant primary contact with the environment and thus with a variety of potential pathogens. As a result, the nose is equipped with a variety of defense mechanisms (mechanical defenses, specific and nonspecific immune responses). As part of the supraglottic vocal tract, the nose also contributes to speech production (see 18.1). Finally, the nose contains the olfactory sensory cells, giving it an essential role in olfaction.

Physical Principles of Nasal Airflow

During inspiration, the air stream enters the nasal vestibule in an oblique vertical direction. Aerodynamically, this air is in a state of laminar flow, meaning that there is no mixing of the different air layers. When the inspired air reaches the nasal valve located between the vestibule and nasal cavity, it passes through the narrowest site in the upper respiratory tract (limen nasi); just past the nasal valve, the cross-section of the airway becomes greatly expanded, creating a “diffuser effect” that transforms most of the laminar flow of the inspired air into turbulent flow, in which different air layers are swirled together. Besides the velocity of the air, thedegreeofchangeinairflowcharacteristicsat this stageisverystrongly influencedbythespecializedanatomy of the nasal cavity, which is subject to substantial individual differences. Septal deviation and cartilaginous or bonyspurs ontheseptum canbe assignificant in this regard as turbinate hyperplasia or septal perforation. To a degree, the transition from laminar to turbulent flow within the nose is functionally desirable because it slows the flow velocity of the inspired air. This prolongs its contact with the nasal mucosa, contributing to olfaction and making it easier for the nose to clean, humidify, and warm the inspired air (see below).

Nasal Cycle

The “nasal cycle” is a physiologic phenomenon marked by an alternation between luminal narrowing and widening of the nasal cavities. This alternate congestion and decongestion of the nasal mucosa is effected mainly through reactions of the venous capacitance vessels of the inferior and middle turbinates, which are regulated by the autonomic nervous system (Fig. 1.11).

Conditioning of the Inspired Air

Inspired air is warmed and humidified in the nose before reaching the lower airways. Turbulent flow and other special physical conditions promote the necessary contact of the inspired air with the nasal mucosa. Moreover, the favorable relationship between the relatively small nasal cavity and the comparatively large mucosal surface area, which is further enlarged by the turbinates, also promotes the functionally important interaction between the inspired air and the mucosa. Humidification is accomplished by secretion and transudation from the nasal glands, the epithelial goblet cells, and the vessels of the lamina propria. Temperature regulation is controlled by the intranasal vascular system and especially the venous erectile tissue, which is particularly abundant in the inferior turbinates. The temperature in the anterior portions of the nasal cavity is lower than in the posterior regions. This temperature gradient produces a gradual warming of the inspired air, while on expiration moisture and heat are returned to the nose through condensation. The warming capacity of the nasal mucosa is so efficient that even with ambient temperatures below zero, the temperature of the inspired air is raised by 25°C on entering the nasopharynx, with a relative humidity of over 90%.

Fig. 1.11 The nasal cycle This coronal computed tomography scan shows mucosal swelling in the right nasal cavity, predominantly on the inferior and middle turbinates, and mucosal decongestion in the right nasal cavity.

Disturbances in the conditioning function of the nose can result from age-related drying of the mucosa due to involution of the goblet cells and glands. They can also result from chronic inflammatory changes or extensive resections of the mucosa during intranasal surgery.

Protective Functions of the Nasal Mucosa

Here the protective functions of the nose are separated into two parts to facilitate learning, although in life the various defense mechanisms are interrelated and should not be thought of as separate entities.

Nonspecific Defense Mechanisms

Mechanical defenses: The most important mechanical defense mechanism of the nasal mucosa is the mucociliary apparatus, which physically cleanses the inspired air. The mucociliary transport system consists of the cilia of the respiratory epithelium and a mucous blanket composed of two layers: a deeper, less viscid “sol layer” in which ciliary motion occurs, and a superficial, more viscid “gel layer” (Fig. 1.12). The physiology of ciliary movements is described in 1.5. Disturbances of mucociliary transport can have various causes, such as increased viscosity and thickness of the periciliary sol layer, hampering ciliary movements, or changes in the viscoelasticity of the gel layer resulting in ineffectual mucus transport. Finally, various pathogenic mechanisms can produce changes in the cilia themselves, regardless of the viscosity of the mucous blanket. For example, an acute viral infection of the upper respiratory tract can lead to desquamation of the epithelium, with a loss of ciliated cells. Also, certain microorganisms can directly affect ciliary motility by reducing the beat frequency of the cilia. Finally, ciliary dyskinesia syndromes are congenital disorders based on morphologic changes in the cilia such as absence of the dynein arms. This results in uncoordinated, dyskinetic ciliary movements that prevent effective mucus transport (see also 3.8).

Fig. 1.12 Mucociliary transport Cilia on the respiratory epithelium beat in a coordinated, metachronous pattern in the periciliary fluid (deeper sol layer), which transports the superficial gel layer toward the nasopharynx (arrow).

1.5 Physiology of ciliary motion

Ciliary motion consists of three phases and is initiated by adenosine triphosphate (ATP)–splitting proteins, which cause a movement of the filaments within the cilia (sliding filament theory). The superficial gel layer is propelled toward the nasopharynx by a coordinated but metachronous beating of the cilia. The dynamics of ciliary motion has been likened to a “field of grain swaying in the wind.” The cilia beat at a high frequency (10–20 times per second), but their motion is influenced by external factors such as temperature and humidity.

Table 1.1 Nonspecific protective factors in nasal secretions

Substance group

Example

Interferon

Proteases

Cathepsin, elastase, chymase, tryptase

Protease inhibitors

α1-Protease inhibitor, C1 inactivator

Lysozyme

Antioxidants

Catalases, glutathione, ascorbic acid

Nonspecific protective factors: The nasal mucosa also has several other, nonspecific defense mechanisms in the form of protective factors in the mucous blanket (Table 1.1).

Cellular defenses: The mucosa has nonspecific defense mechanisms at the cellular level as well. The predominant phagocytic cells are neutrophilic granulocytes, monocytes, and macrophages. They are accompanied by “natural killer cells,” which comprise a small percentage of the peripheral lymphocytes and protect mainly against viral infections of the nasal mucosa.

Specific Immune Responses

Besides the nonspecific defense mechanisms of the nasal mucosa, the nose possesses a specific immune system that can be viewed as a separate immunologic unit. It is made up of the nasal mucosa itself and the lymphoepithelial tissue of Waldeyer’s ring (see below). Recent discoveries indicate that the structures of Waldeyer's ring, especially the pharyngeal and palatine tonsils, function as inductive components that are active in the absorption, processing, and presentation of antigens, whereas the nasal mucosa itself is purely an effector organ in which, for example, foreign material is phagocytized by immunocompetent cells.

The local, specific immune system of the nasal mucosa is based on the actions of antibodies, which are responsible for the humoral immune response, and of immunocompetent cells, which are responsible for the cellular immune response.

Humoral immune response: Antibodies are formed in the paraglandular plasma cells. Most notably, IgA is an immunoglobulin that is characteristic of the respiratory mucosa and therefore of the nasal mucosa. The plasma cells also synthesize IgM and the less common IgC. When released, the immunoglobulins (especially IgA) are absorbed by the glandular cells of the lamina propria, provided with a secretory component, and re-released as secretory antibodies (sIgA).

Cellular immune response: Representatives of the cellular immune response of the nasal mucosa include mast cells, macrophages, various polymorphonuclear leukocytes (neutrophils, basophils, eosinophilic granulocytes), lymphocytes, and the cells of the reticuloendothelial system, which occur chiefly as dendritic (Langerhans’) cells in the nasal mucosa. T lymphocytes are of special importance in the control and memory functions of the immune response, while B lymphocytes can differentiate into plasma cells and thus have a key role in the humoral immune response of the mucosa in connection with local antibody production. Eosinophilic granulocytes are found mainly in association with chronic sinusitis and nasal polyps. Their granules contain cytotoxic substances that can damage tissues by the lysis of cell membranes. Basophilic granulocytes are involved in immediate allergic reactions, although the mast cells are by far the most dominant cell type in this phase. The mast cells are also chiefly responsible for histamine release in the early phase of an allergic reaction. Basophilic granulocytes (the only representatives of polymorphonuclear leukocytes) and mast cells also have a specific receptor (Fc∊R) for binding IgE. On contact with the corresponding allergenic substance, this can incite a devastating allergic reaction that may culminate in anaphylactic shock.

The epithelial cells of the nasal mucosa also have an immune function. In particular, the adhesion molecule ICAM-1, expressed by the epithelial cells, helps to prevent viral infections by acting as a receptor for more than 90% of rhinoviruses.

Finally, the endothelial cells of the blood vessels play an important role in the specific immune responses of the nasal mucosa. The vascular endothelial cells are activated by various inflammatory mediators—for example, interleukin 1, tumor necrosis factor-α (TNF-α)—and they regulate the transendothelial diapedesis of immunocompetent cells into the surrounding tissue through the expression of various adhesion molecules (Fig. 1.13, Fig. 1.14).

Speech Production

Various organ systems are involved in the production of voice and speech. The anatomically separate functions of the respiratory tract, glottis, supraglottic vocal tract, and central nervous system must be coordinated to produce a normal voice sound. The term supraglottic vocal tract refers to the air-containing regions located above the level of the vocal cords. The rigid portions of this tract, whose condition is subject to only minor variations under physiologic conditions (e.g., due to mucosal swelling), include the nose, paranasal sinuses, and portions of the nasopharynx. Their role in articulation is most apparent under pathologic conditions. “Hyponasal speech” (rhinophonia clausa) occurs when these segments of the vocal tract contribute less to sound production as a result of partial or complete nasal obstruction or mass lesions in the nasopharynx. Conversely, “hypernasal speech” (rhinophonia aperta) develops when the nasopharynx and nasal cavities overcontribute to sound production. This occurs when velopharyngeal closure is absent or incomplete (cleft palate, velar palsy due to various causes).

Fig. 1.14 Chronic inflammation of the nasal mucosa Sections from the lamina propria of the nasal mucosa. Increased numbers of lymphocyte function–associated antigen-1 (LFA-1)–labeled leukocytes (brown stain) resulting from transendothelial diapedesis are found in the setting of a chronic inflammatory reaction (a) compared with a control specimen (b) (immunohistochemistry, ABC method with hemalum counterstain).

Olfaction

The human olfactory system consists of the intranasal olfactory mucosa with its specialized olfactory epithelium and associated central pathways. The sensory cells consist of bipolar ORN whose distal processes (cilia) have receptor proteins in their cell membranes, which are involved in the bond of scents. So far, 200 to 400 receptor protein types have been identified in humans. A scent can connect to different receptors with any of its different molecular components. Vice versa, different scents can bond to the same receptor type. The proximal processes of ORN join to form the fila olfactoria, which are relayed through additional neurons and are distributed to the primary, secondary, and tertiary olfactory centers (see 1.2, Olfactory Mucosa). From a purely functional standpoint, an olfactory impression can be received only during inspiration, and only water-soluble and lipid-soluble substances are perceived. Even subtle changes in the chemical properties of a molecule can produce a clearly perceptible difference in the quality and quantity of the olfactory impression. The precise sequence of events that are involved in olfaction is still uncertain.

It is important clinically to differentiate between olfactory disturbances and taste disorders, because the senses of smell and taste are closely interrelated. Patients often believe that they have a dysfunction of both senses, even though an olfactory disturbance is the sole cause of the complaints in more than two-thirds of cases (see Table 2.2).

2 Diagnostic Evaluation of the Nose and Paranasal Sinuses

2.1 History and Clinical Examination of the Nose

Aside from special rhinologic tests, which are reviewed in 2.2, the specific rhinologic history and clinical examination of the nose play a key role in further diagnostic and therapeutic decision-making.

History

Before the examiner asks about specific rhinologic symptoms, patients should be given an opportunity to describe their complaints “in their own words,” as in any history.

The history should begin with questions about general, relatively nonspecific symptoms such as obstructed nasal breathing and nasal discharge. It is important to determine, for example, whether the nasal obstruction (“stuffy nose”) has been present for some time or is of recent onset, possibly in connection with trauma to the nose. Additional questions should elicit whether the complaints are unilateral, bilateral, or alternate between the sides and whether they are seasonal or present year-round.

In patients with nasal discharge, the consistency of the secretions should be assessed: is the discharge watery, mucopurulent, or blood-tinged (which may suggest a tumor)? To exclude allergic rhinitis, the patient should be questioned about sneezing attacks, itchy eyes (conjunctival irritation), cough, and respiratory complaints (evidence for allergic involvement of the lower respiratory tract).

If the history suggests that the disease may have an allergic cause, a specific allergy history should be taken. This includes the family and personal history (bronchial asthma, atopic dermatitis, food allergies) as well as details on the household and occupational environments, giving particular attention to pets, indoor plants, and potential allergen exposure at the workplace (e.g., in a bakery or hair salon).

Headaches may signify an accompanying paranasal sinus inflammation. Dryness of the nasal mucosa is a common finding in colds but can also result from changes in air quality, previous nasal surgery, or the chronic use of vasoconstricting nose drops or sprays that contain corticosteroids. Olfactory dysfunction is another possible symptom of rhinologic diseases, and the patient should always be questioned about this.

Clinical Examination

Inspection

The clinical examination begins with a visual inspection. Findings such as mouth breathing may direct the examiner to suspect nasal airway obstruction. The shape of the external nose may suggest intranasal abnormalities (e.g., a cartilaginous nasal deviation with a tension septum). It is particularly important to evaluate the nasal base (see Fig. 1.4), for which the patient's head should be tilted back. In this position, the examiner can also test the stability of the nasal alae. If the alar cartilages are too soft, they will be indrawn even during normal, unforced inspiration. Skin changes such as erythema or swelling can occur with orbital complications of paranasal sinus inflammations (erythema and swelling of the upper and lower lids), in erysipelas (“butterfly”-shaped erythema of the midfacial skin), or with nasal furuncles, which present with circumscribed redness and swelling in the nasal vestibule.

Palpation

Palpation is most useful for detecting bony discontinuities. In patients with suspected neuralgias, it is also done to check for tenderness over the supraorbital, infraorbital, or mental foramina. In patients with a recent trauma history, palpation of the external nose will disclose any mobility or crepitus suggesting a fracture of the nasal pyramid. The midfacial bones (especially the bony orbital rim) are also palpated to check for step-offs indicating a fracture line. Soft-tissue swelling can limit the accuracy of this examination, however.

Anterior Rhinoscopy

The rhinologic examination itself begins with anterior rhinoscopy to evaluate the nasal vestibule and the anterior portions of the nasal cavity (Fig. 2.1).

Technique: The examiner holds the nasal speculum in the left hand and braces the index finger on the patient's right nostril. The speculum is inserted into the nose with the blades closed. During the examination, the physician uses the right hand to position the patient's head and gently opens the speculum to spread open the nostril to allow inspection of the nasal cavity. The speculum should not be opened too far, as this would cause discomfort. The head should be tilted slightly forward for evaluating the nasal floor, inferior turbinate, and the anterior portions of the septum. The head is tilted backward to obtain a limited view of the middle meatus and middle turbinate. Often, this region cannot be adequately assessed by anterior rhinoscopy alone due to anatomic constraints. As a result, endoscopy is commonly used to examine this region as well as the posterior portions of the nasal cavity and the nasopharynx (see below). When anterior rhinoscopy has been completed, the speculum is carefully withdrawn with the blades slightly open to avoid avulsing hairs from the nasal vestibule.

Fig. 2.1 Anterior rhinoscopy Technique for inspecting the nasal cavity.

In many cases, the nasal mucosa should be decongested with vasoconstrictors prior to the examination, as this makes it easier to examine the interior of the nose. At the same time, it is also important to assess the “original” condition of the nasal mucosa, and so the nose should be examined before and after decongestion of the mucosa.

Indication: Anterior rhinoscopy is used not only for nasal examination but also for minor therapeutic procedures such as intranasal packing for epistaxis, foreign-body removal, and polypectomy.

Children: Smaller instruments (pediatric specula) are available for anterior rhinoscopy in children. Moreover, aural specula can be used to examine the nose in infants or small children.

Decongestants should always be properly diluted when used in children.

Fig. 2.2 Nasal endoscopy Positions of the patient and examiner.

Posterior Rhinoscopy

Posterior rhinoscopy was formerly done to evaluate the nasopharynx and posterior nasal cavity (choanae, posterior ends of the turbinates, posterior margin of the vomer). With the establishment of endoscopic examination techniques in rhinology, this procedure, which requires special patient cooperation, is now considered obsolete.

Nasal Endoscopy

Nasal endoscopy has become the most important and rewarding clinical examination method in rhinologic diagnosis.

Prerequisites: Nasal endoscopy requires practice because, unlike anterior rhinoscopy, it provides only close-up views of small intranasal areas. Besides rigid endoscopes, which are available in 4-mm and 2.8-mm diameters and assorted viewing angles (e.g., 0, 30, 120 degrees), flexible endoscopes are also available for inspecting the nose and nasopharynx and exploring all of the pharynx and larynx in one sitting. Their main disadvantages compared with rigid scopes are their weaker light intensity and poorer image resolution. Also, it takes two hands to operate a flexible endoscope, while a rigid scope leaves one hand free for manipulating instruments.

The patient is seated for the examination (Fig. 2.2). As in anterior rhinoscopy, the preparations include decongestion of the nasal mucosa. A topical anesthetic should also be applied. Diagnostic nasal endoscopy is performed with a 4-mm 30-degree telescope. The 2.8-mm scope is used only in a very narrow nasal cavity or in children.

Fig. 2.3 Nasal endoscopy Nasal endoscope shown in an anatomic specimen (sagittal section). The tip of the scope is in the nasopharynx.

Fig. 2.4 Endoscopy of the nasopharynx Transnasal endoscopic appearance of the nasopharynx.

Fig. 2.5 Endoscopy of the middle meatus Normal appearance of the middle meatus, with the middle turbinate and uncinate process. The asterisk marks the narrow passage through which the endoscope can be advanced into the ostiomeatal unit.

Technique: First, the examiner advances the endoscope into the nasopharynx (Fig. 2.3) and inspects the eustachian tube orifice, torus tubarius, posterior pharyngeal wall, and roof of the nasopharynx (Fig. 2.4). While the transnasal nasopharyngeal inspection can provide very detailed views (e.g., for early detection of nasopharyngeal cancer), it should still be supplemented by transoral postrhinoscopic endoscopy (see 5.2, Mirror Examination and Endoscopy).

Nasal endoscopy is particularly useful for evaluating the ostiomeatal unit (see 1.3), as this pathophysiological important region generally cannot be adequately evaluated by anterior rhinoscopy alone. To inspect the middle meatus, the endoscope is first advanced toward the head of the middle turbinate. This should provide a good overview of the middle meatus (Fig. 2.5).

To advance farther into the ostiomeatal unit, the scope must negotiate the narrow passage between the uncinate process and the middle turbinate (asterisk in Fig. 2.5). Normally, this can be done only with a narrow-gauge scope (2.8 mm). The 4-mm endoscope can be used at this site only in patients who have had previous intranasal sinus surgery with resection of the uncinate process.

Direct endoscopic inspection of the paranasal sinuses is possible only to a limited degree. In some cases, the sphenoid sinus can be examined with a thin telescope passed through the natural ostium in the anterior sinus wall. If endoscopic exploration of the maxillary sinus is required (e.g., for a suspected tumor), it can be done either through the inferior meatus after perforating the lateral nasal wall or by a transfacial approach with incision of the maxillary sinus mucosa and perforation of its anterior wall.

2.2 Special Rhinologic Tests

While the examination methods described thus far are practiced routinely, special rhinologic test procedures are performed only if there is specific evidence that suggests a particular disorder.

Testing Nasal Patency

Simple methods can be used for the preliminary assessment of nasal patency. One such method is to hold a reflective metal plate under the nose; the degree of fogging will give a crude impression of the patency of the tested nasal cavity. Nasal patency in infants can be tested subjectively by holding a wisp of cotton in front of each nostril.

Today, the most standardized procedure for the assessment of nasal patency is active anterior rhinomanometry (Fig. 2.6). This procedure measures and graphically records the difference in pressure (ΔP) from the naris (P2) to the nasopharynx (P1) and the respiratory air volume per unit time (V). One nostril is occluded for this test while the nasal air stream is measured on the opposite side. The accuracy of this test is most limited in patients with severe nasal airway obstruction, and the test cannot be performed when one nasal cavity is completely obstructed. Acoustic rhinometry is described in 2.1.

The differential diagnosis of nasal airway obstruction is outlined in Table 2.1.

Allergy Testing

While the history and nasal endoscopic findings can provide initial, relatively nonspecific evidence of an allergic etiology for rhinitis, allergy testing is used to verify and differentiate this condition. Various in vivo and in vitro methods are available for allergy testing.

Skin Tests

When a small amount of allergen is placed in contact with the skin, it can evoke a local or systemic (!) allergic reaction in a previously sensitized individual. The most widely used method is the prick test, in which the skin is superficially pricked with standard test substances that contain the suspicious antigens. The local skin reaction is compared with the reaction to a simultaneously applied positive control (histamine solution) and negative control (saline solution).

A positive skin prick test proves that sensitization has occurred but does not prove an allergic etiology for the rhinitis.

2.1 Acoustic rhinometry

Acoustic rhinometry is a measuring technique that is based on the principle of acoustic reflection and can be used to determine intranasal cross sections. Unlike rhinomanometry, it does not measure dynamic respiratory function but the cross sections of the nasal cavity at various sites, which are averaged together. The main advantages of this method over rhinomanometry are that it is faster and easier to perform and does not depend on patient cooperation. While these features are desirable in the examination of pediatric patients, it should always be considered that acoustic rhinometry measures static parameters and, unlike rhinomanometry, does not assess the patency of nasal airflow.

Table 2.1 Differential diagnosis of nasal airway obstruction

• Acute and chronic rhinitis (e.g., allergic, atrophic)

• Sinusitis

• Deviated septum (congenital, acquired)

• Nasal pyramid fracture

• Septal perforation

• Nasal polyps

• Cephalocele

• Adenoids

• Tumors of the nose, paranasal sinuses, and nasopharynx

• Foreign bodies (especially in small children)

• Drugs

– Adverse effects: oral contraceptives, antihypertensive agents (e.g., reserpine, propranolol, hydralazine), antidepressants (e.g., amitriptyline)

– Drug abuse: imidazoline derivatives (e.g., oxymetazoline hydrochloride, xylometazoline hydrochloride)

Serologic Tests

The total immunoglobulin E (IgE) assay—e.g., paper radioimmunosorbent test (PRIST)—can be used for the quantitative determination of nonspecific total IgE, and various tests are available for specific IgE determination—e.g., radioallergosorbent test (RAST), enzyme allergosorbent test (EAST), etc. Specific IgE testing is recommended because of the low sensitivity and specificity of the total IgE assay.

Fig. 2.6 Active anterior rhinomanometrya In this example, the left nostril has been occluded. A pressure sensor measures the pressure P1 in the left nasal cavity (= pressure in the nasopharynx), and a second sensor measures P2 in a firmly attached face mask. The difference between the pressures, ΔP, is plotted against the respiratory volume flow V.b The curve (green) starts at the zero baseline. It passes through the right upper quadrant during inspiration, crosses back over the baseline at the end of inspiration, passes through the lower left quadrant during expiration, and returns to the origin at the end of the respiratory cycle. A flatter curve (shown in red) indicates a stenosis in the shaded area of the diagram.c When patency is tested in the left nasal cavity, it is customary to draw the curve in the left upper and right lower quadrants. In practice, the measurements from both nasal cavities are charted in one diagram. Source: Rasp 1997.

Nasal provocation test: This test is of greatest value in allergic rhinitis, as it is the only method in which a specified allergen is placed in direct contact with the nasal mucosa. The technique involves the selective application of an allergen solution to the head of the inferior turbinate. Rhinomanometry (see above), performed before and 20 minutes after application of the allergen, confirms the local allergenic effect of the test substance by showing a significant reduction of nasal patency due to reactive mucosal swelling.

Since provocative testing involves placing the allergen directly on the turbinate, it may incite a severe allergic response or even anaphylactic shock, and proper emergency equipment should be easily accessible in the examination room.

Olfactometry