Human Diseases Table of Contents and Sample Chapter

Human Diseases3rd EditionJohn H. Dirckx, M.D.

Health Professions Institute

Human DiseasesThird Edition

by

John H. Dirckx, M.D.

Health Professions Institute

Modesto, California

2009

Human DiseasesThird Edition

by John H. Dirckx, M.D.

Copyright ©2009, Health Professions Institute

First Edition, Health Professions Institute, 1997Second Edition, Health Professions Institute, 2003

All rights reserved. No portion of this book may be reproduced or transmitted in any formor by any means, electronic or mechanical, including photocopy, recording, or any informationstorage and retrieval system, without written permission from the publisher.

Published byHealth Professions InstituteP. O. Box 801Modesto, California 95353Phone 209-551-2112; Fax 209-551-0404Web site: http://www.hpisum.com

E-mail: [email protected] Crenshaw Pitman, Editor & Publisher

Printed byParks Printing & LithographModesto, California

ISBN: 0-934385-97-1

Last digit is the print number: 9 8 7 6 5 4 3 2 1

For my

daughter Patricia

with love

Preface

Human Diseases is intended to provide students and practitioners of medical transcription with a graspof basic information about the causes, symptoms, diagnosis, and treatment of common diseases. It shouldalso prove useful to workers in the allied health professions, health information management, insurance,law, and other fields who need clear, concise data about these topics. Rare diseases and arcane, trivial,and controversial issues have been carefully avoided throughout.

Discussions of specific diseases are self-contained and can be profitably consulted in isolation fromadjacent material. However, topics are presented in an orderly sequence (proceeding from the general tothe particular and from the known to the unknown) so as to make Human Diseases useful as a textbook.The earlier chapters set forth basic principles, and the later ones discuss, one by one, the bodily systemsand important disorders to which they are subject. Preliminary discussions in each of the later chaptersreview relevant anatomy and physiology and describe symptoms, signs, and diagnostic measures.

This book presupposes some familiarity with the basic concepts and terminology of human biologyand healthcare. Most of the less common terms presented in the text are defined in parentheses when theyfirst occur. A Glossary of concise definitions for these and many other terms can be found at the end ofthe book. Terms that cannot be found in the Glossary should be sought in the Index, and vice versa.

About the Case Studies. The exercises based on case studies (found on the accompanying CD-ROMon the inside back cover) have been designed to impart an element of reality and immediacy to this intro-duction to clinical medicine. The diagnostic process is frequently a series of fumbles and often enoughthe problem goes away (or the patient dies) before any clear diagnosis can be made. Efforts at treatmentgo awry, confuse the clinical picture, aggravate the condition under treatment. Social and psychologicalissues are ever-present to complicate diagnosis and therapy. The patient’s personality, beliefs, and lifestylemay present insurmountable obstacles to a satisfactory outcome.

A puzzle is much harder to solve when pieces are missing, and some pieces are virtually always miss-ing in clinical diagnosis. The history as presented to the physician may be incomplete or inaccurate, diag-nostic maneuvers may yield equivocal or enigmatic results, and the physician may simply be unaware orignorant of the information essential to correct diagnosis and appropriate treatment. To reproduce this ambi-ence of uncertainty and ambiguity, the cases as presented may not accurately or fully represent the underlyingreality, and some of the information needed to answer the questions is not in this book. And some of thequestions simply have no answers.

John H. Dirckx, M.D.

v

Contents

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vArt Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viiiList of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ixAbout the Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Chapter1 The Nature of Disease and the Diagnostic Process . . . . . . . . . . . . . . . . . . . . . . 12 Genetic Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Infectious Diseases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 The Immune System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 Neoplasia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396 Trauma and Poisoning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477 Diseases of the Skin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 558 Diseases of the Cardiovascular System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 679 Diseases of the Ear, Nose, and Throat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8310 Diseases of the Respiratory System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9111 Diseases of the Digestive System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9912 The Excretory System, the Male Reproductive System, and

Sexually Transmitted Diseases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11313 Diseases of the Female Reproductive System . . . . . . . . . . . . . . . . . . . . . . . . . . 12314 Pregnancy and Childbirth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13315 Disorders of Metabolism, Nutrition, and Endocrine Function . . . . . . . . . . . . . . . 14316 Disorders of Blood Cells, Blood-Forming Tissues, and Blood Coagulation . . . . . . . 15317 Musculoskeletal Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16318 Diseases of the Eye . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17119 Diseases of the Nervous System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18120 Mental Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219

The Author . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230

Exercises and Case Studies on CD-ROM, inside back cover

Page

vii

Art Acknowledgments

The numerous medical images and illustrations throughout this textbook were obtained from a number ofsources. Many images used are in the public domain from government institutes such as the National CancerInstitute, Centers for Disease Control, National Eye Institute, National Institutes of Health, National Institute ofMental Health, and Public Health Image Library (PHIL), some of which were made available at no chargethrough www.Wikipedia.org. Other images were licensed for publication use at very low fees from the popu-lar on-line stock photos and image sites, www.Fotolia.com and www.Dreamstime.com.

viii

List of Figures

Figure1 Karyotype of Normal Chromosomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 Clubbing of Fingers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Cleft Lip and Palate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 Down Syndrome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 Oncogenes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 Bacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 Tick . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268 Varicella (Chickenpox) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 Herpes Zoster of the Chest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2810 The Immune System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3011 AIDS Life Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3212 Kaposi Sarcoma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3313 Rheumatoid Arthritis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3514 Metastasis Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4015 How Cancer Spreads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4116 Breast Cancer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4417 Prostate and Nearby Organs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4518 Bowel Resection for Colon Cancer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4619 Microscopic Anatomy of the Skin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5620 Oral Candidiasis (Thrush) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6021 Herpes Simplex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6022 Hemangioma (Strawberry Mark) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6223 Urticaria (Hives) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6424 Skin and Joint Changes in Psoriasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6525 Melanoma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6626 Cardiovascular System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6827 Heart and Vessels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6928 Severe Stenosis of the Carotid Artery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7129 Electrocardiogram Limb and Chest Leads . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7230 Holter Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7231 Implanted Pacemaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7632 The Ear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8433 Nose and Throat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8734 CPAP Treatment for Obstructive Sleep Apnea . . . . . . . . . . . . . . . . . . . . . . . . . 9035 The Respiratory System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9236 Gross Pathology of Centrilobular Emphysema Characteristic of Smoking . . . . . . . . . 9737 The Digestive System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

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List of Figures (continued)

Figure38 Colon and Rectum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10539 Digital Rectal Exam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10640 Inguinal Hernia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10741 Liver and Nearby Organs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10842 Pancreas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11143 Pancreas and Nearby Organs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11144 Male Urinary Tract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11445 Female Urinary Tract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11446 The Kidney . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11647 Male Reproductive System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11948 Female Reproductive System, Lateral View . . . . . . . . . . . . . . . . . . . . . . . . . . . 12449 Female Reproductive System, Anterior View . . . . . . . . . . . . . . . . . . . . . . . . . . 12550 Cells of Cervix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13151 Breast and Lymph Nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13252 Pregnancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13753 Clamping and Cutting of Newborn Umbilical Cord . . . . . . . . . . . . . . . . . . . . . . 13954 Ectopic Pregnancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13955 Endocrine System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14456 Thyroid Gland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14757 Insulin Injection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15158 Foot Examination of Patient with Diabetes . . . . . . . . . . . . . . . . . . . . . . . . . . . 15259 Blood Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15460 Leukemia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15961 Musculoskeletal System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16462 Scoliosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16663 Bursitis of Elbow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16764 Heberden Nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17065 The Eye . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17266 Glaucoma Surgery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17767 Retinal Detachment as Shown by Slit Lamp Examination . . . . . . . . . . . . . . . . . . 17968 Brain and Spinal Cord . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18269 Major Parts of Brain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18370 Meninges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

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About the Exercises

To the Student: Whether you are an independent study student or enrolled in a traditional classroomor distance-education program, you will find Human Diseases an interesting and engaging text. You willget the most from your study efforts if you first familiarize yourself with the entire book, reading all theintroductory material and examining closely the Contents and the Index. Review the last section ofChapter 1 where the author describes how the material is presented and explains key terms. Before read-ing a chapter, review the Chapter Outline and Learning Objectives. Then look ahead to the “Questionsfor Study and Review” on the CD-ROM on the inside back cover. This “preview” sets the stage for whatyou are about to read and will improve your understanding and retention. Complete the exercises for eachchapter as assigned by your teacher. When doing the “Case Study: You’re the Doctor” sections, don’tread ahead until you have completed all the questions for that segment. Don’t look ahead to see whathappens next! The “Suggestions for Additional Learning Activities” are for all students. Some require youto do research outside of this textbook while others may require the assistance of classmates, friends, orfamily members, especially for learning games. Even though these exercises may seem more like fun thanactual work, they promote “whole brain learning” and will aid your mastery of the study of human dis-eases. Answers to objective questions appear on the accompanying CD-ROM as well. Some questions aremore subjective and will not have a single right answer.

To the Teacher: This third edition of Human Diseases contains an expanded and multi-faceted selec-tion of exercises to help your students master the material and build essential critical thinking skills thatwill help them excel in school and in the workplace. “Questions for Study and Review” on the CD-ROMcan be assigned as self-graded homework and discussed in class or be completed in the classroom as atest of reading comprehension. In “Case Study: You’re the Doctor,” students are asked to render theiropinions on both clinical and ethical dilemmas. Have students complete the first case study in the class-room, working together or in small groups, reviewing Dr. Dirckx’s Preface before they begin. The casestudies are presented in segments, each appearing in a shaded box followed by a series of questions.Encourage students to answer all the questions for each segment, without looking ahead to the next seg-ment. In “Suggestions for Additional Learning Activities,” you’ll find ideas for creative classroom activitiesand homework assignments that will add interest and variety to your course. Some activities require studentsto go outside the text for more information. Others require interaction with others in learning groups. Andvirtually all of the individual Learning Activities can be adapted for the classroom by asking students towork together, compare their work with others, or present their findings to the class. The answers to objec-tive questions are placed on the CD-ROM for easy access. An exhaustive Index is also included at the endof the textbook as an indispensable study aid.

Georgia Green, CMT, AHDI-F

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Chapter Outline

THE EAR: ANATOMY AND PHYSIOLOGY

DIAGNOSTIC PROCEDURES IN DISORDERSOF THE EAR

INFECTIONS OF THE OUTERAND MIDDLE EAROtitis Externa (Swimmer’s Ear)Otitis Media

DISORDERS OF THE INNER EARTinnitusVertigoHearing Loss

THE NOSE: ANATOMY AND PHYSIOLOGY

DIAGNOSTIC PROCEDURE IN DISORDERSOF THE NOSE

DISEASES OF THE NOSECoryza (Common Cold)Allergic Rhinitis (Hay Fever)Sinusitis (Rhinosinusitis)Epistaxis (Nosebleed)

THE THROAT: ANATOMY AND PHYSIOLOGY

DIAGNOSTIC PROCEDURES IN DISORDERSOF THE THROATAcute Pharyngitis (Sore Throat)Obstructive Sleep Apnea (OSA)

QUESTIONS FOR STUDY AND REVIEWSee CD-ROM inside back cover.

Diseases of the Ear,Nose, and Throat

9

LEARNING OBJECTIVES

Upon completion of this chapter, youshould be able to

• describe the basic anatomy andphysiology of the ears, nose, andthroat;

• explain diagnostic procedures andtreatments used for diseases of theears, nose, and throat;

• classify common diseases of the ears,nose, and throat by their signs,symptoms, and treatment.

83

DISEASES OF THE EAR, NOSE,AND THROAT

The ears, nose, and throat are adjacent to oneanother anatomically, similar in histologic structure,and subject to many of the same diseases. Diseases,injuries, and abnormalities of the ear, nose, and throat(ENT) are the special field of the otorhinolaryngolo-gist. This chapter briefly surveys the more commondisorders to which these parts of the body are subject.If you encounter unfamiliar terms, look them up in theGlossary or the Index.

THE EAR

ANATOMY AND PHYSIOLOGY

Each ear has three parts (See Figure 32):1. The outer ear, consisting of the pinna (the car-

tilaginous appendage on either side of the head, whichcollects sound waves like a funnel) and the externalauditory meatus (a tube that conducts sound wavesfrom the pinna to the middle ear). The meatus is linedwith skin that secretes cerumen (earwax), a mildly

antimicrobial substance that traps dust and other par-ticulate foreign material.

2. The middle ear, a cavity in the temporal boneseparated from the external auditory meatus by thetympanic membrane, which vibrates in response tosound waves and imparts the vibration to a series ofvery small bones (malleus, incus, and stapes), which inturn transmit them to the inner ear.

3. The inner ear, consisting of the cochlea (anorgan shaped like a snail shell, in which sound vibra-tions are converted to nerve impulses to be sentthrough the eighth cranial, or vestibulocochlear, nerve)and the vestibular system (the organ of balance, con-taining minute position sensors in a fluid medium,which send information about head position to the bal-ance center in the brain, also through the eighth cranialnerve).

The middle ear communicates with the pharynx bya minute passage called the auditory (eustachian) tube,which serves to equalize air pressure between the mid-dle ear and the atmosphere (see box). It also commu-nicates with epithelium-lined air cells within the skull,called mastoid air cells.

84 • Human Diseases

Figure 32. The Ear

Inner Ear3 EarBones

AdenoidsEustachianTubeMiddle

EarOuter Ear

National Institute on Deafness and Other Communication Disorders, National Institutes of Health

DIAGNOSTIC PROCEDURESIN DISORDERS OF THE EAR

Inspection and palpation of the pinna.

Otoscopy: Inspection of the external auditory mea-tus and tympanic membrane with an otoscope, aninstrument that directs light into the ear through a con-ical speculum, and is equipped with a magnifying lens;mobility of the tympanic membrane can be assessedwhen the subject swallows or performs the Valsalvamaneuver (or when, in children, the examiner blows apuff of air into the ear with a rubber bulb attached tothe otoscope).

Measurements of hearing: (1) simple tests withticking watch or tuning fork; (2) audiography, a precisemeasurement of the faintest loudness (in decibels) thatthe subject can hear, each being ear tested separately ateach of several pitches (for example, 250, 500, 1000,2000, 3000, 4000, 6000, and 8000 Hz); this can beperformed by a technician with carefully calibratedtesting equipment, or by automated machinery acti-vated by the subject; (3) more elaborate testing of thesubject’s ability to discriminate spoken words.

Weber test: A vibrating tuning fork placedfirmly against a bony surface of the head at the mid-line sends vibrations through the bones of the skull.These should be heard equally in the two ears; if thereis hearing loss due to blockage of the external audi-tory meatus or to injury or disease of the middle ear,the tone of the fork will be heard louder in the affectedear; in hearing loss due to damage to the inner ear oracoustic nerve, however, the tone will be heard louder inthe more normal ear.

Rinne test: The sound of a vibrating tuning forkpositioned so that the tines are near the pinna (air con-duction) should be heard by the subject even after thesound sensed when the shank of the tuning fork isplaced on the mastoid process behind the ear (boneconduction) can no longer be heard; when bone con-duction is heard longer than air conduction in an earwith reduced hearing, the hearing loss is due toobstruction of the meatus or disease of the middle ear.

Tympanocentesis: Puncture of the tympanic mem-brane and withdrawal of fluid from the middle ear forexamination, including culture.

Pneumotympanometry: Assessment of the mo-bility of the tympanic membrane by applying pressureto its outer surface with a device fitting tightly in theexternal meatus.

INFECTIONS OF THE OUTERAND MIDDLE EAR

Otitis Externa (Swimmer’s Ear)Infection of the external auditory meatus.Causes: Infection with bacteria (Proteus, Pseudo-

monas) and sometimes fungi (Aspergillus). Predis-posing causes include water exposure (swimming,showering), excessive cerumen, mechanical trauma(probing with paperclip), foreign body (cotton, pencileraser), diabetes mellitus, and immune compromise.

History: Earache, itching in the external auditorymeatus, purulent discharge. Hearing loss if the meatusis occluded by swelling or exudate.

Physical Examination: Redness and swelling ofthe meatus, sometimes with complete occlusion; puru-lent exudate, perhaps with excessive cerumen or for-eign body visible. Tenderness on manipulation of thepinna.

The auditory tube between the middle earand the pharynx was discovered by BartolomeoEustachio (1524-1574), an Italian anatomist whoalso made important studies of the heart, the kid-ney, and the nervous system.

It has been suggested that when WilliamShakespeare wrote Hamlet, he had in mind thethen recent discovery of this passage. In Act I,Scene 5, the ghost of Hamlet’s father tellsHamlet how he was murdered by his brotherClaudius, who poured “juice of cursed hebona. . . in the porches of my ears.”

According to Nomina Anatomica (NA) andTerminologia Anatomica (TA), the name of thistube is tuba auditoria (or auditiva), usually ren-dered auditory tube in English.

Many health professionals nonetheless clingto the traditional name, eustachian tube, andmost of them pronounce it with the soft Frenchch sound (as in champagne) rather than the moreappropriate hard Italian ch (as in Chianti).

Chapter 9 • Ear, Nose, and Throat • 85

Course: Generally benign, but in diabetes mellitusand AIDS an external ear infection may resist conser-vative treatment and become chronic, perhaps invadingthe skull or brain, with resulting neurologic damage.

Treatment: After gentle cleansing and removal ofany foreign material, cerumen, or exudate, topicalantibiotics (ear drops), often with hydrocortisone tocombat local inflammation, are instilled several times aday. Sometimes a gauze wick is inserted to facilitatepenetration of ear drops when edema of the meatus isextreme. In invasive infections, intravenous antibioticsand even surgery may be required.

Otitis MediaBacterial infection of the middle ear and adjoining

mastoid air cells.Cause: Infection by Streptococcus pneumoniae,

Haemophilus influenzae, Streptococcus pyogenes, andother bacteria. Otitis media commonly occurs as asequel to a viral upper respiratory infection. Ob-struction of the auditory tube by edema leads to pres-sure changes within the middle ear and secretion ofmucus and serous fluid, which becomes infected bybacteria already present in the tissues. Otitis media isoften bilateral. It is commoner in infants and smallchildren than in adolescents and adults, accounting forone-third of all pediatric office visits.

History: Pain and pressure in one or both ears,hearing loss, sometimes fever.

Physical Examination: Redness of the tympanicmembrane, sometimes with formation of bullae.Immobility of the tympanic membrane, reflecting mal-function of the auditory tube. Occasionally bulging ofthe membrane. If spontaneous rupture occurs, blood orpurulent exudate in the external auditory meatus.

Course: It is estimated that 20-80% of all cases ofotitis media will resolve spontaneously without treat-ment. When there is fever or severe pain, antibiotictreatment is usually prescribed because of the risk ofserious complications in a few patients. Neglect of theinfection, its failure to respond to standard initial treat-ment, or a series of recurrent infections can lead tochronic otitis media, typically due to different organ-isms (Proteus, Pseudomonas, staphylococci) than acuteinfection. Complications of chronic otitis mediainclude spontaneous rupture of the tympanic mem-brane, with chronic purulent drainage; destruction ofthe bones within the middle ear that transmit sound;invasion of mastoid air cells (mastoiditis), skull bones,and even the central nervous system by infection; for-mation of cholesteatoma, a benign but locally invasive

growth of the tympanic membrane caused by prolongednegative pressure (partial vacuum) in the middle ear.Chronic otitis media can lead to permanent conductivehearing loss and, in small children, speech defectsbecause of inability to hear speech sounds properly.

Treatment: In the absence of fever and severe painin patients over age 2, analgesics and observation arepreferred to antibiotic treatment. For selected patients,systemic antibiotics (amoxicillin with or without clavu-lanic acid, erythromycin, trimethoprim-sulfamethoxa-zole), decongestants, analgesics. If tympanic membranerupture threatens, myringotomy (surgical puncture ofthe membrane, with release of pus). In children withrecurrent or refractory infections, polyethylene tubesmay be placed in the tympanic membrane(s) to aeratethe middle ear(s) and allow for escape of purulent secre-tion. Cholesteatoma and mastoiditis are treated surgi-cally. Chronic perforation of the tympanic membranerequires surgical repair (tympanoplasty).

DISORDERS OF THE INNER EAR

TinnitusPerception of abnormal sounds in the ear(s) or head.

When pulsatile (simultaneous with heartbeat), it mayresult from vascular disease (arterial stenosis, aneu-rysm). Tinnitus is generally a humming or squealingnoise heard constantly or intermittently in one or bothears, especially at night when external sounds are at aminimum. It is generally due to degenerative disease ofthe inner ear, and frequently accompanies sensorineuralhearing loss (discussed below). Common causes areexcessive noise exposure and certain medicines. Aspirinand other salicylates at higher doses cause tinnitus last-ing only as long as they remain in the body. Other drugs(certain antibiotics) can cause permanent tinnitus.Treatment of tinnitus is generally unsatisfactory butincludes masking with other sounds (music, “static” ona radio).

VertigoA sense of motion (spinning, falling, floor tipping)

when no such motion is occurring.Causes: Labyrinthitis, often following respiratory

infection and hence often called viral. Degenerativechanges in the balance-sensing mechanism of the innerear. Increased pressure within the endolymphatic sac(Ménière disease). Vascular or neoplastic disease of theinner ear or temporal lobe of the cerebral cortex.Diplopia, head injury, multiple sclerosis, drugs, alcohol.


History: A feeling of spinning or falling to oneside, or a sense that the floor is tipping or rotating,coming on suddenly, often with head movement, andlasting seconds, minutes, hours, days, weeks, ormonths. When severe, vertigo may make it impossiblefor the patient to stand or walk, and may be accompa-nied by nausea and vomiting. There may also be tinni-tus and hearing loss.

Physical Examination: May be essentially nor-mal. The Romberg test (patient standing with eyesclosed) may indicate inability to maintain equilibrium.Eyes may show nystagmus.

Treatment: May be limited to treatment of theunderlying cause. In Ménière disease, salt restrictionand diuretic therapy may help by reducing the pressureof the endolymph. Medicines such as meclizine anddimenhydrinate may diminish or abolish vertigo tem-porarily. In some cases of positional vertigo, headmanipulation can reduce symptoms by promotingreorientation of the balance mechanism.

Hearing LossReduction, often permanent, in the acuity of hear-

ing in one or both ears. Hearing loss is divided intothree types depending on the location of the abnor-mality.

Conductive hearing loss: Disease or abnormalityin the outer or middle ear: cerumen impaction, otitismedia with effusion, hardening of the tympanic mem-brane (otosclerosis), injury or disease of the ossicles.

Sensory hearing loss: Disease of the cochlea:acoustic trauma, ototoxicity (aminoglycosides, loopdiuretics, cisplatin), aging.

Neural: Eighth nerve lesions; cerebrovasculardisease.

Hearing loss is assessed by audiometry and theWeber and Rinne tests. Treatment is that of the under-lying cause, if possible.

Generally no treatment is effective.

THE NOSE


The external nose (Figure 33) is supported by aframework of cartilage and covered by skin. The nos-trils (anterior nares) open into paired passages linedwith mucous membrane, which is rich in serous andmucous glands and blood vessels. The lining mem-brane of these passages is closely attached to convo-

luted ridges of bone called turbinates (three on eachside), which increase the surface area of membranethat is exposed to inspired air. Adjacent to the nasalpassages, and communicating with them by narroworifices, are the paranasal sinuses. These are cavitieswithin the bones of the skull, somewhat variable insize and shape, and lined with mucosa like that of thenose. The nasal passages end at the choanae, or pos-terior nares, where they enter the nasopharynx, theuppermost part of the pharyngeal cavity. The nasalpassages warm and moisturize inspired air, and themucus film lining them traps particulate matter in theair.

DIAGNOSTIC PROCEDUREIN DISORDERS OF THE NOSE

Direct inspection with nasal speculum orrhinoscope.

Posterior rhinoscopy: Inspection of posteriornares with angled mirror placed in the oropharynx.

Figure 33. Nose and Throat


Alan Hoofring, National Cancer Institute

Diagnostic Tests: Nasal smear shows eosinophils.Skin testing or RAST (radioallergosorbent testing) canidentify causative allergens.

Treatment: Decongestants, antihistamines, nasalcorticosteroid spray. Avoidance of known allergenswhen possible. Use of air filters as appropriate. Con-tinued administration of desensitizing antigens oftenmarkedly reduces symptoms.

Sinusitis (Rhinosinusitis)Infection of one or more paranasal sinuses.Cause: Involvement of the paranasal sinuses often

occurs along with any type of rhinitis, including par-ticularly the common cold. Swelling of the nasalmucosa leads to blockage of the sinus openings, withaccumulation of secretions within the sinuses affected.Persons with allergic rhinitis may be subject to recur-ring episodes of sinusitis due to chronic blockage ofsinus openings (ostia). Acute sinusitis is nearly alwaysviral. Recurrent or persistent obstruction to sinusdrainage can lead to chronic sinusitis with secondarybacterial infection.

History: Pressure or pain in one or more sinuscavities, often aggravated by bending forward. Pain maybe manifested as a severe headache or may radiate intothe teeth. Purulent or bloody nasal or postnasal dis-charge may be present. Occasionally fever, chills, andmalaise.

Physical Examination: Edema and erythema ofnasal mucosa. Purulent discharge in nasal passages ororopharynx (postnasal drip).

Diagnostic Tests: In chronic sinusitis, x-ray orother diagnostic imaging shows thickening of sinusmembranes and often presence of fluid within cavities.

Treatment: Decongestant, analgesic. A shortcourse of nasal decongestant spray may help to openand drain sinuses. Control of allergic component ifpresent. When symptoms (severe, persistent pain) orclinical picture (fever, bloody discharge) suggests bac-terial infection, an oral antibiotic (amoxicillin, tri-methoprim-sulfamethoxazole) is prescribed. Chronicsinusitis may respond to prolonged antibiotic therapy.Surgical procedures can be used to correct anatomiclesions predisposing to sinusitis, or to improve drainageof a chronically infected sinus.

Epistaxis (Nosebleed)Bleeding from the nose may be due to nasal

trauma, irritation of the mucosa by dust or dry air,upper respiratory infection or allergic rhinitis, or coag-ulation defect. Treatment of acute nosebleed is by

Nasal smear: Examination of a stained smear ofscrapings from the nasal mucosa for evidence of infec-tion (neutrophilic leukocytes) or allergy (eosinophilicleukocytes).

Culture of nasal secretions to identify bacterialpathogens.

Diseases of the Nose

Coryza (Common Cold)A common, mild rhinitis caused by viruses.Causes: Any of numerous viruses, which can be

spread readily from person to person. Risk of catchingcold may be heightened by exposure to severe winterweather (especially whole-body chilling), drying ofindoor air by heating systems, or crowding indoors dur-ing the winter.

History: Headache, nasal stuffiness, runny nose,sneezing, throat irritation, malaise. Occasionally fever,chills, anorexia, and muscle aching.

Physical Examination: Erythema and edema ofnasal mucosa. Temperature may be slightly elevated.

Course: Generally self-limited. Sometimes com-plicated by sinusitis, otitis media, pharyngitis, bron-chitis.

Treatment: Purely symptomatic. Oral deconges-tants are moderately effective. Aspirin, acetaminophen,or ibuprofen relieve discomfort. Rest, fluids. Anti-histamines do not decongest, antibiotics do not kill coldviruses, and nasal decongestant sprays cause reboundcongestion worse than the disease.

Allergic Rhinitis (Hay Fever)A recurrent, often seasonal, inflammation of the

nasal mucous membrane caused by allergy to inhaledmaterials.

Causes: Sensitivity to pollens, grasses, moldspores, dust mites, animal dander, second-hand ciga-rette smoke, and other inhalant allergens.

History: Recurrent or constant nasal congestionand irritation, with copious watery discharge, itching,sneezing (often many times in a row), and itching andwatering of the eyes. Symptoms may occur consistentlyat certain seasons (spring, fall) or, especially when dueto house dust, may be perennial.

Physical Examination: Watery, red eyes. Pale orbluish, markedly swollen nasal mucosa. Nasal polyps(massive overgrowths of chronically inflamed mucosa)may be present.


application of direct pressure and, if necessary, topicalvasoconstrictor. If bleeding persists or recurs, cauterywith silver nitrate or anterior nasal packing may benecessary. Rarely bleeding comes from the posteriornares (usually in middle-aged or elderly patients withhypertension or arteriosclerosis) and requires a poste-rior nasal pack. Prevention of further nosebleeds mayinclude use of lubricating applications to the mucosa,humidification of air, and avoidance of dusts and otherirritants.

THE THROAT


The throat (Figure 33), or pharynx, is a cavity linedwith mucous membrane that conducts air from the noseand mouth into the trachea, and food and drink from themouth into the esophagus. It consists of three portions:the nasopharynx, on a level with the nasal passages andcommunicating with them; the oropharynx, on a levelwith the mouth and communicating with it; and thehypopharynx or laryngopharynx, which lies below theoropharynx and gives entry to the esophagus and thelarynx.

The tonsils and adenoids are masses of lymphoidtissue surrounding the zone between the mouth and theoropharynx. At the boundary between the oropharynxand the hypopharynx lies the epiglottis, a flexible valvethat closes the respiratory passage during swallowing offood or drink.

The lining of the pharynx secretes mucus, whichkeeps the surface moist, traps inhaled particles, andsupplements the saliva as a lubricant for food. Lymphglands in the front and back of the neck receive lym-phatic drainage from the throat and adjacent structures.

DIAGNOSTIC PROCEDURESIN DISORDERS OF THE THROAT

Inspection of the throat with a focused light, oftenwith the aid of a tongue depressor (tongue blade) topress the tongue out of the field of vision.

Palpation of cervical lymph glands and of masses,swellings, or other structures within the throat.

Throat culture to identify bacterial pathogens.Strep screen (faster than culture, but detects only

group A beta-hemolytic streptococci).

Biopsy of masses or lesions suspected of beingmalignant.

X-ray or other imaging to identify foreign bodies,masses, or abnormalities of the airway due to injury ordisease.

Acute Pharyngitis (Sore Throat)Acute inflammation of the throat due to infection.Cause: Usually viruses, including the Epstein-Barr

virus, which causes infectious mononucleosis (dis-cussed in Chapter 3). Occasionally bacteria such asStreptococcus pneumoniae and Group A beta-hemolytic Streptococcus pyogenes (“strep throat”), orfungi such as Candida. Infection with cold viruses maypredispose to bacterial infection. Sore throat is moreprevalent in cold weather.

History: Pain, irritation, or a sense of fullness orswelling in the throat, accentuated by swallowing andoften radiating to the ears. Fever, painful glandularswelling in the neck.

Physical Examination: May be essentially nor-mal. Fever is often present. Edema and erythema of theoropharynx, often involving the tonsils, soft palate, anduvula, occur in most bacterial and many viral throatinfections. Severe infections, including streptococcalpharyngitis (strep throat) and infectious mononucleosis,cause formation of white or gray exudate (consisting ofdead tissue, white blood cells, and bacteria) on pha-ryngeal walls and especially on the tonsils. A firmlyadherent exudate is characteristic of Candida infection(thrush). The presence of vesicles or ulcers suggestsviral infection (herpes simplex virus, coxsackievirus).Severe pain and swelling may cause a hollow or “hotpotato” voice, and may make swallowing virtuallyimpossible, so that the patient drools to avoid swallow-ing saliva, and becomes dehydrated from lack of fluidintake. Extreme swelling may compromise the airway.Cervical lymph glands may be swollen and tender.Some strains of beta-hemolytic streptococci cause awidespread red rash (scarlet fever, scarlatina).

Diagnostic Tests: Throat culture or strep screenmay identify the causative organism. Blood studies(white blood cell count and differential, antistreptolysinO titer, heterophile antibodies) help to diagnose strepthroat and infectious mononucleosis. Smears or scrap-ings of exudate can confirm presence of Candida.

Course: Viral sore throat runs its course within aweek or two. Occasionally it becomes complicated bystreptococcal infection, which may lead to acute rheu-matic fever. It may also progress to otitis media, acute


or chronic tonsillitis, or lower respiratory infection.Peritonsillar abscess (quinsy) is a severe bacterial infec-tion developing above and behind one tonsil and caus-ing extreme pain and swelling, with deviation of theuvula away from the affected side.

Treatment: Acute viral pharyngitis requires notreatment except analgesics, gargles, soothing lozenges,and perhaps a soft diet. Adrenal corticosteroid may beadministered orally or by injection for severe pain andswelling. If streptococcal infection is diagnosed, a 10-day course of an antibiotic known to be able to eradi-cate streptococci (such as penicillin V, erythromycin,or cephalexin) is mandatory. Candidal oropharyngitis(thrush) is treated with topical or systemic antifungalmedicine. The treatment of peritonsillar abscess is sur-gical drainage.

Obstructive Sleep Apnea (OSA)A disorder in which breathing is repeatedly inter-

rupted during sleep by intermittent obstruction of theairway.

Cause: Lax, excessively bulky, or malformedpharyngeal tissues (soft palate, uvula, and sometimestonsils). Obesity, hypothyroidism, cigarette smoking,alcohol, and some medicines (particularly benzo-diazepines) are predisposing factors. The swallowingreflex may be impaired during sleep. The condition istwice as common in men. Incidence increases withadvancing age.

History: Loud snoring and recurrent episodes ofapnea (respiratory arrest) during sleep followed by gasp-ing inspiration with partial or complete arousal. Theperiod of apnea may last for 10-120 seconds, and maybe accompanied by sinus bradycardia or atrioventricularblock.

Physical Examination: The shape and caliber ofupper respiratory passages may be abnormal.

Diagnostic Tests: Polysomnography (continuousmonitoring of heart rate, respiratory action and airflow, eye movements, and electroencephalogram duringsleep), supplemented by recording of chin movementsand arterial oxygen saturation.

Course: Nocturnal hypoxemia (deficiency of oxy-gen in blood) and shallow, non-refreshing sleep maylead to daytime lethargy, difficulties with memory andconcentration, and even personality change and acci-dent-proneness. About 15% of persons with OSAdevelop sustained pulmonary hypertension.

Treatment: Weight loss, smoking cessation, avoid-ance of alcohol and benzodiazepines. An applianceworn inside the mouth may reduce symptoms by hold-ing the lower jaw in a forward position. The nightly useof continuous positive airway pressure (CPAP), whichprovides a steady flow of room air at low pressurethrough the nose to overcome intermittent upper respi-ratory obstruction, is often effective (Figure 34). Surgi-cal trimming and reshaping of the uvula and soft palatecan be performed by laser or radiofrequency ablationunder local anesthesia. A more elaborate procedure ismandibular osteotomy with genioglossus muscleadvancement.

Figure 34. CPAP Treatmentfor Obstructive Sleep Apnea


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