Kochars clinical medicine for students

LAMB, MD, FACP Associate Professor of Medicine Division of General Internal Medicine Associate Director, Joint Quality Office Froedtert Hospital and Medical College of Wisconsin Milwauke

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K O C H A R ’ S

CLINICAL MEDICINE FOR STUDENTS

FIFTH EDITION

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K O C H A R ’ S

CLINICAL MEDICINE FOR STUDENTS

FIFTH EDITION

EDITOR-IN-CHIEF DARIO M TORRE, MD, MPH, FACP

Associate Professor of Medicine Medical College of Wisconsin/Zablocki VA Medical Center

Medicine Clerkship Director Milwaukee, Wisconsin

EDITORS GEOFFREY C LAMB, MD, FACP

Associate Professor of Medicine Division of General Internal Medicine Associate Director, Joint Quality Office Froedtert Hospital and Medical College of Wisconsin

Milwaukee, Wisconsin

JEROME J VAN RUISWYK, MD, MS, FACP

Associate Professor of Medicine Medical College of Wisconsin Associate Chief of Staff for Clinical Affairs Zablocki VA Medical Center Milwaukee, Wisconsin

RALPH M SCHAPIRA, MD, FACP, FCCP

Professor and Vice-Chairman of Medicine Medical College of Wisconsin Chief of Medicine Zablocki VA Medical Center Milwaukee, Wisconsin

CONSULTING EDITOR MAHENDR S KOCHAR, MD, MS, MACP, FRCP (LONDON)

Professor of Medicine Senior Associate Dean, Graduate Medical Education

Medical College of Wisconsin Milwaukee, Wisconsin

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Marketing Manager:Jennifer Kuklinski

Design Coordinator:Teresa Mallon

Associate Production Manager:Kevin Johnson

Compositor:Maryland Composition

Copyright䉷 2009 Lippincott Williams & Wilkins

351 West Camden Street

repro-The publisher is not responsible (as a matter of product liability, negligence, or otherwise)for any injury resulting from any material contained herein This publication contains infor-mation relating to general principles of medical care that should not be construed as specificinstructions for individual patients Manufacturers’ product information and package insertsshould be reviewed for current information, including contraindications, dosages, and precau-tions

Printed in the United States of America

Library of Congress Cataloging-in-Publication Data

Kochar’s clinical medicine for students / editor in chief, Dario M Torre ; editors, Geoffrey

C Lamb, Jerome Van Ruiswyk, Ralph M Schapira ; consulting editor, Mahendr S

1 Clinical medicine 2 Internal medicine I Torre, Dario M II Kochar’s concise textbook

of medicine III Title: Clinical medicine for students

[DNLM: 1 Clinical Medicine 2 Internal Medicine 3 Primary Health Care WB 115K756 2008]

To purchase additional copies of this book, call our customer service department at (800) 638-3030 or fax orders to (301) 223-2320 International customers should call (301) 223-2300.

Williams & Wilkins customer service representatives are available from 8:30 am to 6:00 pm,EST

06 07 08 09 10

1 2 3 4 5 6 7 8 9 10

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To Alessia, innocent rainbow, beautiful, eternal flower in the garden of my life.

Dario Torre

To students, who always challenge and inspire their teachers.

Geoffrey Lamb, Jerome Van Ruiswyk, Ralph Schapira, Mahendr Kochar

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F O R E W O R D

Twenty-five years of Kochar!

Following the 4th edition of Kochar’s Concise Textbook of Medicine, faculty and students around the country can now welcome its new incarnation, Kochar’s Clinical Medicine for Students, reconceived

in its overall structure and rewritten in every detail The new Kochar helps students meet the core

tenet of professionalism in internal medicine—fulfilling a duty of expertise for each and everypatient—but also moves with its students into the 21st century The principles and the insistence

on rigor in the clinical essentials are the same, but these days, we all learn in new ways, and we

access information differently The new Kochar is true to the basics, while adapting itself to the

needs of a new generation

From the beginning, Dr Kochar conceived a book that could be read by students during their

3rd year clerkship Throughout its earlier editions, Kochar has prided itself on providing exactly the

information that students and residents needed to take care of their patients, in a way that theycould quickly access and effectively apply In a word, it was ‘‘concise.’’ The new edition does thistoday, and to the same high standards as the previous four editions, as would be expected of a text

in use in medical schools throughout the country

Under the general editorship of Dr Dario Torre, it is almost entirely rewritten, brought to-date in every respect He and the section editors and faculty of the Medical College of Wisconsinhave done right by their readers The table of contents reflects the curriculum guide of the ClerkshipDirectors in Internal Medicine and the website of the United States Medical Licensing Examination.There has been a growing national consensus in medical education that every graduating student

up-should have mastered basic clinical skills, and the 5th edition of Kochar opens with an entirely new

section, ‘‘Key Manifestations and Presentations of Disease.’’ This section describes all the key toms and findings that clinicians look for in patients, and links these to a basic understanding ofphysiology All by itself, this section could be used in introduction to clinical medicine and basic

symp-‘‘doctoring’’ courses throughout the country The section editor, also Dr Torre, and chapter authorshave created something that covers all the common problems, while still remaining concise In otherwords, it contains all the basics, with just the right amount of material for which all students can

be held accountable

The ‘‘Diseases and Disorders’’ section is organized by traditional organ systems Every chapterhas been rewritten in detail, and the majority of authors are new to the 5th edition While maintainingthe goals of clarity and conciseness, the level of expertise is appropriate for residents in internalmedicine and family medicine, and this edition keeps faith with the view of Dr Kochar that generalmedicine and primary care are essential to the practice of every specialty and subspecialty A new

‘‘Ambulatory Medicine’’ section of 18 chapters, edited by Dr Jerome Van Ruiswyk, has been oped for those clerkships that have also an ambulatory component

devel-Finally, this edition of Kochar is linked to an interactive website, which supplements each section’s

description with multimedia materials, images, and demonstrations of findings in support of the

vii

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text For instance, cardiology is supported with multiple EKGs, dermatology with striking images.Students will also appreciate the interactive online multiple-choice questions.

Innovation and tradition are the hallmarks of the new Kochar The new General Editor for this

edition is Dr Dario Torre, Associate Professor of Medicine and Internal Medicine Clerkship Director

at the Medical College of Wisconsin Dr Geoffrey Lamb has written several sections and joins thegroup as Associate Editor Two editors remain from the 4th edition: Dr Jerome Van Ruiswyk, inwriting the new section on ‘‘Ambulatory Medicine’’, one which we can ask all students to read atthe start of their ambulatory rotations with adult patients, and Dr Ralph Schapira’s guidance isretained throughout, especially in the Pulmonary section Although he is no longer an editor, thepresence of Dr Kesavan Kutty, editor of the 2nd, 3rd and 4th editions, is gratefully retained in thesection chapter on tuberculosis

The editors and authors of the new Kochar have thought carefully about what essential

knowl-edge and skills students still need in the contemporary world of medicine—high speed, dense and less time than ever between students and patients But as Dr Kochar wrote in 1982, ‘‘there

information-is only one way to learn clinical medicine, and that information-is at the bedside,’’ where everything information-is anchored

in the students’ own experience with their patients The new Kochar’s Clinical Medicine will keep

them on course

Louis N Pangaro, MD, FACP

Vice Chair for Educational Programs

Department of MedicineUniformed Services University of the Health Sciences

F Edward He´bert School of MedicinePast President, Clerkship Directors of Internal Medicine

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P R E F A C E

‘‘Few will be found to doubt the importance of books as means to .the end of all study—the capacity to make a good judgment,’’ Sir William Osler.

The acquisition of knowledge is essential to creating diagnostic hypotheses and achieving

a solution to the patient’s clinical problem With that in mind, we have developed the 5th

edition of Kochar’s Clinical Medicine for Students to link theoretical information more closely

to the practice of medicine Although direct patient experience is an irreplaceable way to develop the practice of medicine and patient care, theoretical knowledge is still an essential component of the learning process Formal knowledge, which can be acquired from a book, serves as the basis for the application of knowledge in the context of the clinical practice, allowing the student to continuously learn from their experiences.

This edition of Kochar’s has undergone major changes and a significant transformation

to meet the current needs of students in the health professions, in particular the needs of medical students in their third and forth years of medical school.

The conceptual framework behind the development of this book was based on the ADDIE instructional model: Assessment of the learners’ needs, Development, Demonstra- tion, Implementation, and Evaluation of each section of the book This process occurred constantly throughout the manuscript process, to ensure the creation of a text that was centered on the actual needs of the student.

The 5th edition has been substantially revised, reorganized, and updated Because the duration of courses or clerkships in medical schools is restricted, we decided to include only

a selected number of key topics, which were chosen from two sources: Clerkship Directors in Internal Medicine (CDIM) core medicine clerkship curriculum guide, created by a national consensus of clerkship directors and academic general internists from the Society of General Internal Medicine (http://www.im.org/CDIM), and from USMLE ™ Step II Clinical Knowl- edge (CK) content outline (www.usmle.org).

We also recognized that it was important not only for students to learn the typical presentation and diagnosis of common diseases, but also to recognize patients presenting with a specific complaint or finding, for which the generation of diagnostic hypotheses and their evaluation is essential Finally, it was important to introduce a brief ambulatory medicine section to correspond to the ambulatory component included in many medicine clerkships.

Another innovation of this edition is the collaborative effort between general internists and subspecialists; every chapter was written and reviewed by both groups We believe that this cooperation will ensure accuracy, readability, and a more appropriate depth of content for medical students In particular, the depth and relevance of content and the language used throughout the book were specifically revised Additionally, 3rd and 4th year medical students acting as reviewers were involved in the development of the book from the beginning Their feedback was most helpful, and their comments and suggestions were incorpo- rated into the editing process.

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The organization and presentation of the material is divided into three sections: the diagnostic and clinical approach to common presenting complaints with particular attention

to elements of the differential diagnosis; disease and disorders frequently encountered in medicine, formally described in a logical and structured manner; and principles of ambulatory medicine This organization of content yields a broad, yet still selective, number of topics and approaches in inpatient and outpatient settings We have organized the material

so that it will make sense to 3rd year medical students who need to gain an understanding and knowledge of medicine, and to 4th year medical students who want to further their knowledge for clinical problem solving as well as prepare for the USMLE ™ Step II Clinical Knowledge exam We also intend this book to be a resource for nurse practitioners and physician assistants who would like to review in a rapid and concise manner a number of medicine topics.

A strong electronic component has been added to this edition of Kochar’s This content

is well organized and easy to access on the Lippincott Williams & Wilkins website called The Point The Point is an electronic interactive platform that provides students and instruc- tors not only access to the additional online material, but also the ability to interact with each other during the length of the course if they wish to do so The electronic content includes more than 30 additional chapters and approximately 300 multiple-choice questions with detailed explanations To help students prepare for end-of-clerkship exams, such as the NBME Medicine subject test (also known as the ‘‘Shelf exam’’), these questions have been divided into three practice shelf exams The three exams rigorously follow the NBME medicine subject test blueprint available at the official NBME website Each of the three tests contains the same percentage of organ system-based questions currently present on the NBME Medicine subject test Tables and images of electrocardiograms and x-rays are also available on The Point, as well as a bibliography and suggested readings.

The editorial team has also undergone changes with Dr Torre, new Editor-in-Chief, and Dr Lamb joining Drs Van Ruiswyk and Schapira who were editors of the 4th edition.

Dr Kochar, Founder and Editor-in-Chief of the first two editions of the book, serves as

a consulting editor We truly hope that students, who are the brightest hope for the healing and comfort of those who suffer, learn from this book Our greatest wish is that this book will ultimately improve the practice of medicine by linking this theoretical information to clinical practice If learning is a lifelong process and not a destination, let us begin this journey with you!

Dario Torre Geoffrey Lamb Jerome Van Ruiswyk Ralph Schapira

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A C K N O W L E D G M E N T S

We express our appreciation to the contributors and their office staff who have worked diligentlyand patiently in getting their literary contributions into our hands on time The Editorial Staff atLippincott Williams & Wilkins, including Dona Balado, Nancy Duffy, Liz Stalnaker, JenniferKuklinski, and Catherine Noonan

We would also like to take this opportunity to thank Dr G Richard Olds, The John and LindaMellowes Professor and Chairman, Department of Medicine, Medical College of Wisconsin, and Dr.Lee A Biblo, Professor and Vice-Chairman, Department of Medicine, Medical College of Wisconsin,for their emphatic and unyielding support of this book and their enthusiasm that served to inspireeach of its contributors and members of the editorial team

Thank you to Dr Ann B Nattinger, Professor and Chief, General Internal Medicine, ment of Medicine, Medical College of Wisconsin, for your enthusiastic support of this project, whichserved to inspire and energize the authors

Depart-We would also like to offer our sincere thanks to Dr Piero Antuono who gave generously ofhis time as a reviewer His expertise and careful eye ensured a continued high standard of qualityand his efforts are greatly appreciated by our team

The editors would like to extend their deepest gratitude to Kenneth Howe, MA, for his ing organizational skills Ken combines an easy and approachable manner with a tireless work ethic,both of which served to keep us focused, organized, and motivated so we could meet our highestexpectations for this book His efforts are very much appreciated by the Editorial team

outstand-We gratefully acknowledge the contributions of Dr Mahendr Kochar whose gentle ment and quiet leadership helped us to bring forth our best effort

encourage-xi

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Mental Health Division

Zablocki VA Medical Center

Milwaukee, Wisconsin

Raj Bhargava, MD, FACP, FAAP (Key

Manifestation)

Clinical Assistant Professor of Medicine

Medical College of Wisconsin

Professional Internal Medicine Services, SC

St Joseph Regional Medical Center

Lee Biblo, MD (Cardiology)

Vice-Chairman for Clinical Activities

Professor of Medicine

Department of Medicine

Diane Book, MD (Neurology)

Assistant Professor of Neurology

Department of General Neurology

Christopher Chitambar, MD, FACP (Oncology)

Professor of Medicine Division of Neoplastic Diseases Department of Medicine Medical College of Wisconsin Milwaukee, Wisconsin

Asriani (Ria) Chiu, MD, FACP (Allergy & Clinical Immunology)

Assistant Professor of Pediatrics and Medicine Division of Allergy and Immunology Medical College of Wisconsin Chief, Section of Allergy Zablocki VA Medical Center Milwaukee, Wisconsin

Mary Cohan, MD (Geriatrics)

Assistant Professor of Medicine Division of Geriatrics & Gerontology Department of Medicine

Medical College of Wisconsin Milwaukee, Wisconsin

Sumanth Daram, MD (Allergy & Clinical Immunology)

Assistant Clinical Professor Medical College of Wisconsin

St Joseph’s Hospital Milwaukee, Wisconsin

Susan Davids, MD (Infectious Diseases)

Assistant Professor of Medicine Department of Medicine Medical College of Wisconsin Milwaukee, Wisconsin

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Kathryn Denson, MD (Geriatrics)

Assistant Professor of Medicine

Division of Geriatrics and Gerontology

Steve Denson, MD (Rheumatology)

Division of Geriatrics and Gerontology

Assistant Professor of Pediatrics and Medicine

Janet Fairley, MD (Dermatology)

Professor of Dermatology

Chief of Dermatology

Deidre Faust, MD (Rheumatology)

Karen Fickel, MD (Ambulatory Medicine)

Director, Sargeant Internal Medicine Clinic

Jose´ Franco, MD (Gastroenterology &

Hepatology)

Associate Professor of Medicine

Division of Gastroenterology and Hepatology

Virginia Gennis, MD (Behavioral Medicine)

Richard Gibson, MD (Behavioral Medicine)

Assistant Professor of Psychiatry Department of Psychiatry Medical College of Wisconsin Zablocki VA Medical Center Milwaukee, Wisconsin

Amandeep Gill, MD (Key Manifestation)

Hospitalist Department of Medicine Medical College of Wisconsin Milwaukee, Wisconsin

Jerome Gottschall, MD (Hematology)

Professor of Pathology Department of Pathology Medical College of Wisconsin Milwaukee, Wisconsin

Paul Halverson, MD, FACP (Rheumatology)

Professor of Medicine Division of Rheumatology Department of Medicine Medical College of Wisconsin Milwaukee, Wisconsin

Avery Hayes, MD (Key Manifestation)

Shibin Jacob, MD (Key Manifestation & Nephrology)

Hospitalist Department of Medicine Medical College of Wisconsin Milwaukee, Wisconsin

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C O N T R I B U T O R S xv

Safwan Jaradeh, MD, FACP (Neurology)

Professor and Chairman of Neurology

Department of Neurology

Jasna Jevtic, MD (Infectious Diseases)

Albert Jochen, MD (Endocrinology)

Division of Endocrinology, Metabolism &

Clinical Nutrition Department of Medicine

James Kleczka, MD, FACC (Cardiology)

Medical Director, Cardiology Inpatient Services & CICU

Division of Cardiology

Robert Krippendorf, MD (Dermatology)

Kesavan Kutty, MD, FACP, FCCP

(Pulmonary Disease & Critical Care)

Geoffrey C Lamb, MD (Cardiology)

Gunnar Larson, MD (Psychiatry)

Assistant Professor of Psychiatry

Department of Psychiatry

Jon Lehrmann, MD (Psychiatry)

Assistant Professor of Psychiatry Department of Psychiatry Medical College of Wisconsin Zablocki VA Medical Center Milwaukee, Wisconsin

Ann Maguire, MD, MPH (Key Manifestation)

Bob Maglio, MD (Ambulatory Medicine)

Ellen McCarthy, MD (Nephrology)

Associate Professor of Medicine Division of Nephrology & Hypertension Department of Medicine

University of Kansas Medical Center Kansas City, Kansas

Theodore MacKinney, MD, MPH, FACP (Ambulatory Medicine)

Julie Mitchell, MD, MS (Key Manifestation & Ambulatory Medicine)

Marcos Montagnini, MD (Key Manifestations & Geriatrics)

Assistant Professor of Medicine Division of Geriatrics & Gerontology Department of Medicine

Tayyab Mohyuddin, MD (Cardiology)

Assistant Professor of Medicine Hospitalist

Department of Medicine Medical College of Wisconsin Milwaukee, Wisconsin

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Martin Muntz, MD (Neurology)

Joan Neuner, MD (Ambulatory Medicine)

Gwen O’Keefe, MD (Key Manifestation)

Associate Chief of Endocrinology

Division of Endocrinology, Metabolism &

Clinical Nutrition Department of Medicine

Vishal Ratkalkar, MD, FACP (Cardiology)

St Joseph’s Hospital

Robert Riniker, MD (Nephrology)

Elizabeth Russell, MD (Key Manifestation)

Kia Saeian, MD (Gastroenterology & Hepatology)

Assistant Professor of Medicine Director, GI Endoscopy Laboratory Division of Gastroenterology and Hepatology Department of Medicine

Linus Santo Tomas, MD (Pulmonary Disease & Critical Care)

Assistant Professor of Medicine Division of Pulmonary/Critical Care Department of Medicine

Virginia Savin, MD (Nephrology)

Professor of Medicine Division of Nephrology Department of Medicine Medical College of Wisconsin Milwaukee, Wisconsin

Ralph M Schapira, MD, FACP, FCCP (Pulmonary Disease & Critical Care)

Professor and Vice-Chairman of Medicine Medical College of Wisconsin

Chief of Medicine Zablocki VA Medical Center Milwaukee, Wisconsin

Siddhartha Singh, MD (Pulmonary Disease & Critical Care)

Christopher Sobczak, MD (Ambulatory Medicine)

Assistant Professor of Medicine & Pediatrics Departments of Medicine & Pediatrics Medical College of Wisconsin Milwaukee, Wisconsin

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C O N T R I B U T O R S xvii

Kimberly Stoner, MD (Ambulatory

Medicine & Psychiatry)

Instructor

Heather L Toth, MD (Key Manifestation)

Assistant Professor of Medicine & Pediatrics

Departments of Medicine & Pediatrics

Dario M Torre, MD, MPH, FACP

(Ambulatory Medicine & Cardiology)

Medicine Clerkship Director

Department of Medicine, VA Medical Center

Jerome J Van Ruiswyk, MD, MS, FACP

(Ambulatory Medicine & Geriatrics)

Associate Chief of Staff for Clinical Affairs

Jeff Wesson, PhD, MD (Nephrology)

Division of Nephrology

Krista Wiger, MD (Gastroenterology & Hepatology)

Priya Young, MD (Dermatology)

Assistant Professor of Dermatology Department of Dermatology Medical College of Wisconsin Milwaukee, Wisconsin

Jennifer R Zebrack, MD, FACP (General Internal Medicine)

Associate Professor of Medicine Division of General Internal Medicine University of Nevada School of Medicine Reno, Nevada

Monica Ziebert, MD, DDS (Key Manifestation)

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4. Altered Mental Status 19

JULIE MITCHELL and DARIO TORRE

DARIO TORRE and JOSE´ FRANCO

9. Dizziness and Vertigo 48

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13. Fever and Rash 72

16. Heart Sounds and Murmurs 86

GEOFFREY C LAMB and DARIO TORRE

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LINUS SANTO TOMAS

36. Chronic Obstructive Pulmonary Disease 232

LINUS SANTO TOMAS

37. Interstitial Lung Disease 239

LINUS SANTO TOMAS

45. The Solitary Pulmonary Nodule 269

LINUS SANTO TOMAS

Rheumatology—Deidre Faust, Paul Halverson, and

Steve Denson

46. Osteoarthritis 274

STEVEN DENSON and PAUL HALVERSON

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47. Rheumatoid Arthritis 279

DEIDRE FAUST and PAUL HALVERSON

48. Systemic Lupus Erythematosus 288

49. Polymyositis and Scleroderma 294

50. Sjo¨gren’s Syndrome 298

51. Seronegative Spondyloarthropathies 300

52. Wegener’s, Polyarteritis Nodosa, Polymyalgia Rheumatica, and

Temporal Arteritis 305

53. Gout and Other Crystal-induced Synovitis 310

54. Infectious Arthritis 314

Infectious Diseases—Michael Frank

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69. Diseases of the Adrenal Glands 427

JENNIFER ZEBRACK and ALBERT JOCHEN

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80. Chronic Renal Failure 512

SHIBIN JACOB and VIRGINIA SAVIN

90. Iron Deficiency Anemia 569

JOHN CHARLSON and JENNY PETKOVA

91. B12Deficiency and Other Megaloblastic Anemias 573

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DIANE BOOK and MARTIN MUNTZ

108. Intracerebral and Subarachnoid Hemorrhage 660

DIANE BOOK and MARTIN MUNTZ

109. Seizures 665

MARTIN MUNTZ and DIANE BOOK

110. Headaches 668

111. Normal Pressure Hydrocephalus 671

MARTIN MUNTZ and SAFWAN JARADEH

115. Amytrophic Lateral Sclerosis 684

MARTIN MUNTZ and SAFWAN JARADEH

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KIMBERLY STONER and JON LEHRMANN

Dermatology—Priya Young, Robert Krippendorf, and Janet Fairley

ROBERT KRIPPENDORF, PRIYA YOUNG, and JANET FAIRLEY

127. Basal Cell Carcinoma, Actinic Keratoses, Squamous Cell Carcinoma, and Malignant Melanoma 732

128. Urticaria 738

129. Disease Prevention and Screening 742

JEROME VAN RUISWYK

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137. Knee, Shoulder, and Other Regional Musculoskeletal Syndromes 792

JEROME VAN RUISWYK

138. Upper Respiratory Tract Infection 801

ROBERT MAGLIO

139. Sexually Transmitted Diseases 805

CHRISTOPHER SOBCZAK

Women’s Health Issues

140. Menstrual Concerns and Menopause 814

JULIE MITCHELL and JENNIFER ZEBRACK

141. Polycystic Ovary Syndrome and Hirsutism 820

JENNIFER ZEBRACK and JULIE MITCHELL

144. Delirium and Dementia 834

JEROME VAN RUISWYK and EDMUND DUTHIE

145. Urinary Incontinence 840

MARY COHAN and KATHRYN DENSON

146. Benign Prostatic Hypertrophy 843

JEROME VAN RUISWYK

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E15. Blood Transfusion

JENNY PETKOVA, JOHN CHARLSON, and JEROME GOTTSCHALL

E16. Heparin Induced Thrombocytopenia

JENNY PETKOVA

Nephrology—Virginia Savin

E17. Acid-Base Disorders

VIRGINIA SAVIN

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C O N T E N T S xxix

E18. Renal Tubular Acidosis

VIRGINIA SAVIN

Psychiatry—Jon Lehrmann

E19. Somatoform Disorders

JEROME VAN RUISWYK and JON LEHRMANN

E20. Substance Abuse

JEROME VAN RUISWYK and JON LEHRMANN

Dermatology—Priya Young and Robert Krippendorf

E21. General Approach to Dermatologic Disorders

ROBERT KRIPPENDORF

E22. Dermatitis and Eczema

E23. Vitiligo

E24. Herpes

E25. Common Warts

E26. Eryspipelas

E27. Scabies

Allergy and Clinical Immunology—Sumanth Daram and

Asriani Chiu

E28. Anaphylaxis

SUMANTH DARAM and ASRIANI CHIU

E29. Drug Allergy

SUMANTH DARAM and ASRIANI CHIU

Ambulatory Medicine—Jerome Van Ruiswyk

E30. Chronic Pain

THEODORE MACKINNEY

E31. Red Eye

JEROME VAN RUISWYK

E32. Benign Breast Problems

E33. Preconception Care and Issues in Pregnancy

E34. Functional Decline in Elderly Patients

KATHRYN DENSON and MARY COHAN

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IKey Manifestations and Presentations of Diseases Dario Torre

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Abdominal Pain

Jose´ Franco

Abdominal pain is one of the most common indications for patients seeking health care It is a cause

of significant morbidity and mortality Annual costs are in the billions of dollars as a result of directhealth costs, as well as indirect costs through lost wages and productivity

Although abdominal pain can be classified as acute or chronic, this chapter will focus only onacute pain

syn-is better localized and tends to be ‘‘sharper.’’ Unlike vsyn-isceral pain, the patient prefers to remainmotionless Referred pain is felt at sites distant from the involved organs and is the result of conver-gence of visceral afferent and somatic neurons from different locations

Gastroenteritis is most commonly the result of a virus The patient characteristically complains

of nonfocal, crampy abdominal pain that is mild to moderate in intensity and temporally progressesover days before peaking and resolving Associated symptoms include low-grade fevers, nausea, emesisnot related to meals, and diarrhea Examination reveals generalized tenderness without evidence ofguarding or rebound With more severe cases, there is evidence of dehydration that may manifest

as sunken eyes, dry mucous membranes, skin tenting, and orthostatic hypotension

Appendicitis typically begins with vague periumbilical pain associated with nausea and ally vomiting, which progresses over the course of 6 to 10 hours to a more intense and localized pain

occasion-in the right lower quadrant Symptoms are not consistently associated with meals Low-grade feversare common The presence of involuntary guarding and rebound pain are peritoneal signs and, alongwith high fevers, suggest perforation

Biliary colic is the result of intermittent obstruction of the cystic duct by calculi The pain isdull and is localized to the right upper quadrant and epigastric region The duration typically is 6

to 8 hours and may be preceded by a fatty meal Associated symptoms include nausea, emesis, andoccasionally low-grade fevers Between pain episodes, the patient may be asymptomatic for days toyears

Cholecystitis is caused by persistent obstruction of the cystic duct by calculi, which causes toms similar to those of biliary colic but differs in that symptoms persist beyond the 6- to 8-hour

symp-2

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C H A P T E R 1 • AB DOMI NAL P AIN 3

TABLE 1.1 Differential diagnosis of acute abdominal pain

Small bowel obstruction

Perforated peptic ulcer

Mesenteric ischemia

Ruptured abdominal aortic aneurysm

period The pain can be localized to the epigastric area and right upper quadrant or radiate towardthe right scapular region (Chapter 72)

Pancreatitis typically presents with epigastric pain that progresses in severity over the course ofhours to days Although initially described as vague, the pain becomes more localized, unrelenting,and is associated with radiation to the back Associated symptoms include nausea, vomiting, andfever Although symptoms are generally progressive, they most commonly worsen with meals Exami-nation varies depending on severity but may include hypoactive bowel sounds, guarding, and rebound.Intra-abdominal bleeding into the pancreatic bed, in very severe cases, may manifest with periumbili-cal (Cullen’s sign) or flank (Gray-Turner’s sign) ecchymoses (Chapter 75)

Diverticulitis is an infection of colonic diverticula It is most commonly seen in elderly patientsand usually involves the sigmoid colon The pain is initially poorly localized to the lower mid-abdomen and is described as dull With progression of symptoms, over hours to days, localization

to the left lower quadrant occurs Associated nausea, vomiting, and fever are common Examinationreveals tenderness, guarding, and possibly a palpable mass (Chapter 77)

Abdominal pain

Referred

Distant from involved organs

Distal colon pelvic structures

Epigastric

Visceral (associated with nausea/vomiting)

Esophagus, stomach, liver, pancreas, small intestine

Figure 1.1 • Types of abdominal pain.

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Small bowel obstruction in adults is most commonly the result of intra-abdominal adhesionsfrom previous surgeries Depending on the site of obstruction, the patient may complain of epigastric(upper small bowel obstruction) or periumbilical (distal small bowel obstruction) pain that is fre-quently described as crampy Emesis of bilious or feculent material is common Examination revealsdistension, diffuse tenderness, and hyperactive bowel sounds Peritoneal symptoms typically are ab-sent Low-grade fever may be present.

Perforated peptic ulcer most commonly occurs in the proximal portion of the duodenum Thepain is severe and initially localized to the epigastric region; however, gastric and intestinal contentsquickly spread down the right pericolic gutter, leading to diffuse peritonitis Examination frequentlyreveals hypotension, tachycardia, involuntary guarding, abdominal rigidity, and rebound (Chapter70)

Mesenteric ischemia typically is seen in patients with compromised intestinal circulation such

as those with cardiac arrhythmias, peripheral vascular disease, and hypercoagulable states Theseconditions predispose patients to acute arterial and venous insufficiency The pain is poorly localized

to the epigastric and periumbilical regions and is frequently described as having developed suddenly

A detailed history, however, will reveal preceding milder pain that worsens with meals and issuggestive of pre-existing ischemia Examination will reveal an uncomfortable patient with relativelybenign findings seemingly out of proportion to the severe subjective complaints Evidence of gastroin-

TABLE 1.2 Differential diagnosis of nonabdominal causes of adominal pain

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C H A P T E R 1 • AB DOMI NAL P AIN 5

testinal bleeding is common If bowel infarction has occurred, vital signs are unstable with hypotensionand tachycardia being present

Abdominal aortic rupture is a rapidly occurring event Patients present with acute midabdominalpain that is described as ‘‘tearing.’’ The patient is typically hemodynamically unstable with hypoten-sion and tachycardia Femoral pulses are diminished to absent and skin mottling is present Nonab-dominal causes of abdominal pain should also be considered in the differential diagnosis (Table 1.2)

signifi-Changes in the quality and severity of abdominal pain over time are frequently helpful indetermining the etiology Pain that progresses over hours to days and resolves spontaneously oversimilar time periods is suggestive of gastroenteritis If family members and close encounters of thepatient have similar symptoms, this also suggests gastroenteritis Pain whose presence and intensitywaxes and wanes over days to weeks is suggestive of biliary colic Pain that is progressive over timewithout waxing and waning, unless medical intervention is provided, could indicate diverticulitis,pancreatitis, and cholecystitis Pain that develops acutely, frequently without prodromal symptoms,and rapidly progresses in minutes to an hour is seen in perforated peptic ulcer disease and rupturedabdominal aortic aneurysm

Factors that lead to the development or exacerbation of pain are also helpful in determiningthe cause of abdominal pain Symptoms that develop upon swallowing suggest an esophageal source.Pain that decreases with flatus or bowel movements suggests a colonic source and, less frequently,small bowel disease Pain associated with any movement suggests peritonitis, whereas musculoskeletalpain may be caused by fatigue but no particular bodily movement

SPECIFIC DISORDERS

Gastroenteritis is self-resolving in the majority of patients and can be managed conservatively withoutthe need for extensive evaluation When there is evidence of volume depletion, biochemical testingshould include complete blood count with differential, electrolytes, and renal functions, which mayshow leukocytosis with left shift, hypokalemia, and prerenal azotemia, respectively In addition,urinalysis to evaluate for urinary tract causes of pain, including infection, should be obtained Abdomi-nal imaging is rarely helpful

Appendicitis should be evaluated with a complete blood count including differential, which willshow leukocytosis with a left shift; a chemistry panel, which frequently reveals acidosis, multipleelectrolyte disorders, and renal dysfunction; and urinalysis to evaluate for a urinary tract process.Computed tomography should be performed because it will reveal an inflamed appendix and occa-sional pericecal fluid collections

Biliary colic should be evaluated with an abdominal ultrasound, which will reveal gallstones.Laboratory evaluation is typically unremarkable but may rarely reveal cholestatic liver tests with anelevated alkaline phosphatase and bilirubin

Acute cholecystitis will result in inspiratory arrest on palpation of the right subcostal region(Murphy’s sign) Radiographic evaluation most commonly includes ultrasound, which will reveal the

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presence of stones and, occasionally, gallbladder wall edema and pericholecystic fluid phy will demonstrate failure of the gallbladder to take up contrast Biochemical testing revealsleukocytosis with a left shift and frequently mild transaminase, alkaline phosphatase, and bilirubinelevation.

Cholescintigra-Pancreatitis is evaluated with amylase and lipase testing and a liver panel Cholestasis suggestsgallstone pancreatitis There is typically leukocytosis with a left shift and, in more severe cases, ametabolic acidosis Imaging traditionally includes computed tomography, which serves multiple pur-poses including the exclusion of other abdominal pathology, staging the pancreatitis, and determining

if complications such as necrosis and abscess are present

Diverticulitis will occasionally result in a palpable left lower quadrant mass Laboratory testingwill reveal leukocytosis with possible left shift and pyuria if the involved segment is adjacent to theureter or bladder Computed tomography is the most useful imaging study when evaluating thepatient with diverticulitis because it provides localization as well as identification of possible abscess

or fistula

Small bowel obstruction on auscultation will reveal increased high-pitched bowel sounds rated by episodes of relative quiet Radiographic evaluation should include plain abdominal imaging,which confirms the diagnosis (air-fluid levels) as well as localizes the site of obstruction In atypicalcases, oral contrast studies with barium as well as computed tomography are helpful in confirmingthe diagnosis Laboratory testing reveals mild leukocytosis and, in patients with significant vomiting,electrolyte disorders and prerenal azotemia may be present

sepa-Perforated peptic ulcer disease is most commonly due to nonsteroidal anti-inflammatory agents inthe elderly Examination reveals diffuse peritonitis with a rigid board-like abdomen Plain abdominalradiographs or computed tomography will reveal free air Upper gastrointestinal series with water-soluble contrast will reveal the site of perforation if initial imaging is inconclusive Upper endoscopyshould be avoided in patients with suspected perforation Laboratory testing will typically revealleukocytosis with a left shift as well as a metabolic acidosis

Mesenteric ischemia most commonly occurs in specific subgroups as previously described Ahigh index of suspicion is necessary because the abdomen is frequently soft and nondistended insome patients The development of peritoneal symptoms suggests bowel infarction Laboratory testingincludes leukocytosis with a left shift, metabolic acidosis, and elevated lactic acid levels Selectivemesenteric angiography is the diagnostic study of choice and also offers therapeutic options.Ruptured abdominal aortic aneurysm is a catastrophic event typically occurring in patientswith atherosclerotic disease The patient will present in hemodynamic shock Laboratory testingdemonstrating acidosis suggests lack of tissue perfusion Numerous studies including ultrasound andcomputed tomography are helpful, but mortality remains high

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as the bicarbonate decreases, the chloride will increase and the anion gap will be maintained Forexample, a typical normal gap acidosis patient would present with Na 140 mEq/L, HCO316 mEq/

L, Cl 113 mEq/L, and an anion gap of 11 mEq/L In patients with an elevated anion gap acidosis,the bicarbonate decreases and the anion gap increases reflecting an increase in unmeasured anions.For example, a typical anion gap acidosis would present with a Na 140, HCO316, Cl 105, and ananion gap of 20 mEq/L Several disorders and medications and toxins can cause an anion gap acidosis.Advanced renal failure is the most common cause of metabolic anion gap acidosis in the outpa-tient setting When kidney function deteriorates (creatinine⬎3.0 mg/dL), sulfates, phosphates, andmetabolic waste products accumulate Patients often complain of constitutional symptoms such asfatigue, nausea, and anorexia Serum HCO3rarely decreases below 12 and the anion gap characteristi-cally remains⬍20 mEq/L

Lactic acidosis is the most common cause of metabolic anion gap acidosis in the hospitalizedsetting Lactic acidosis develops secondary to tissue hypoperfusion most commonly from septic shock.Patients with septic shock will classically present with fever, tachypnea, tachycardia, and hypotension.Medications, including metformin in the setting of renal failure and antiretroviral therapy, can alsolead to lactic acidosis Serum lactate levels can confirm lactic acidosis

Ketoacidosis elevates the anion gap secondary to the overproduction of the ketoacids, acetoaceticacid, and␤-hydroxybutyric acid Ketoacidosis typically occurs in three settings: diabetic ketoacidosis,starvation ketoacidosis, and alcoholic ketoacidosis Diabetic ketoacidosis (DKA) occurs primarily inpatients with compete insulin deficiency such as type 1 diabetes mellitus but it also occurs in type 2

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TABLE 2.1 Common causes of acid-base disorders

Normal anion gap

Diarrhea

Renal tubular acidosis (RTA)

Ureteral diversions

Early renal insufficiency

High anion gap

Ethylene glycol (앖 osmolar gap)

Methanol (앖 osmolar gap)

Gastrointestinal (GI) losses

Respiratory control center depression

Medications and toxins

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