Master the Boards
Step 2 CK
Master the Boards
Step 2 CK
IN FULL COLOR
USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the
National Board of Medical Examiners (NBME), neither of which sponsors or endorses
This publication is designed to provide accurate information in regard to the subject
matter covered as of its publication date, with the understanding that knowledge and
best practice constantly evolve. The publisher is not engaged in rendering medical,
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This publication is not intended for use in clinical practice or the delivery of medical
care. To the fullest extent of the law, neither the Publisher nor the Editors assume any
liability for any injury and/or damage to persons or property arising out of or related to
any use of the material contained in this book.
© 2015, 2013, 2011 by Conrad Fischer, MD
The authors of the following sections have granted Conrad Fischer, MD, and Kaplan
Publishing exclusive use of their work:
Elizabeth V. August, MD: Section 6, Obstetrics and Gynecology
Alina Gonzalez-Mayo, MD: Section 9, Psychiatry
Niket Sonpal, MD: Section 4, Surgery, and Section 5, Pediatrics
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Elizabeth August wishes to acknowledge Professor Edward C. August, Mrs. Donna M.
August, and Eric D. August for their love, generosity, and unwavering support. Without
them, my dreams would not be a reality.
Niket Sonpal wishes to acknowledge Mr. Navin Sonpal, Mahendra Patel, Raj Patel, and
Dr. Mukul Arya for their unwavering support, hope, and stance by me through thick and
thin. Without them my path to becoming a physician would not have been possible.
The authors wish to acknowledge the expert attention to detail of Dr. Ana Franceschi
and Dr. Gabriel Vílchez Molina.
About the Author
Conrad Fischer, MD, is director of the residency program at Brookdale University
Hospital and Medical Center in New York City. Dr. Fischer is associate professor of
physiology, pharmacology, and medicine at Touro College of Osteopathic Medicine in
New York City.
Elizabeth V. August, MD, is chief medical officer of Bergen County for Riverside
Medical and Pediatric Group and former chief resident at Hoboken University Medical
Center–NY Medical College (2012–2013). She is co-author of the best-selling review
book Master the Boards: USMLE Step 3.
Alina Gonzalez-Mayo, MD, author of the Psychiatry section, is a psychiatrist at Bay
Pines VA Medical Center in Bay Pines, Florida.
Niket Sonpal, MD, is former chief resident at Lenox Hill Hospital–North Shore–LIJ
Health System (2013–2014) and assistant clinical professor of medicine at both Touro
College of Osteopathic Medicine and St. Georges University School of Medicine. He is
a fellow in gastroenterology and co-author of the best-selling review books Master the
Boards: USMLE® Step 3 and Master the Boards: Internal Medicine.
Imaging Editor: Pramod Theetha Kariyanna, MD
Ethics: Robert Goldberg, DO, Professor and Dean of Touro College of Osteopathic
Cardiology: Hal Chadow, MD
Endocrinology: Chris Paras, DO
Neurology: Robert Goldberg, DO; Anjula Gandhi, MD
Infectious Diseases: Farshad Bagheri, MD; Richard Cofsky, MD
Gastroenterology: Anjula Gandhi, MD
Oncology: Vlad Gottlieb, MD; Hamza Minhas, MD
Preventive Medicine: Herman Lebovitch, MD
Rheumatology: Debabrata Sen, MD
Nephrology: Debabrata Sen, MD
General Medicine: Sudheer Chauhan, MD
Hematology: Vlad Gottlieb, MD; Hamza Minhas, MD
For Test Changes or Late-Breaking Developments
The material in this book is up-to-date at the time of publication. However, the
Federation of State Medical Boards (FSMB) and the National Board of Medical
Examiners (NBME) may have instituted changes in the test after this book was
published. Be sure to carefully read the materials you receive when you register for the
test. If there are any important late-breaking developments—or any changes or
corrections to the Kaplan test preparation materials in this book—we will post that
information online at kaptest.com/publishing.
Table of Contents
How to Use This Book
Section 1: Internal Medicine
Chapter 1: Infectious Diseases
Chapter 2: Allergy and Immunology
Chapter 3: Cardiology
Chapter 4: Endocrinology
Chapter 5: Pulmonology
Chapter 6: Rheumatology
Chapter 7: Hematology
Chapter 8: Gastroenterology
Chapter 9: Neurology
Chapter 10: Nephrology
Chapter 11: Oncology
Section 2: Preventive Medicine
Section 3: Dermatology
Section 4: Surgery
Section 5: Pediatrics
Section 6: Obstetrics and Gynecology
Section 7: Radiology
Section 8: Ophthalmology
Section 9: Psychiatry
Section 10: Emergency Medicine
Section 11: Ethics
Master the Boards: Step 2 CKis a complete book for your preparation for USMLE Step
2 CK. You do not need to use other books. As an educator, I get asked a lot of questions
on the best way to prep. Here’s the question I hear most: “Is this enough?” The answer
to that question is a definite “yes!” Additional materials will still help you to reinforce
what you have learned, but this is a smart first step to Step 2 CK success. Another
question I get is about how to maximize medical knowledge. The best preparation for
Step 2 CK is to learn more medicine.
Your Guide to the USMLE
Frequently, medical students wonder when they should take Step 2 CK. Well, the
answer to this question depends on your background and level of knowledge. There is
no requirement to have to take Step 1 before you take Step 2 CK, although for U.S.
graduates, this is almost certainly what happens. Remember, U.S. graduates do not have
to take Step 2 CK in order to participate in the annual residency match. International
graduates must take Step 2 CK to be ECFMG certified. ECFMG certification is
required for international graduates in order to be in the match.
For the vast majority of U.S. medical students, USMLE Step 1 is generally taken at the
end of the second year of medical school. Some schools will, in fact, require passage of
Step 1 in order to be allowed promotion into the third year of school and to participate
in clinical rotations. For some international schools, particularly those in the Caribbean
in which virtually the entirety of the class is headed for residency in the United States,
they will follow this pattern as well.
Timing can be a factor for some U.S. graduates, too. For example, if you have a great
grade on USMLE Step 1 and you are applying to a moderately competitive specialty,
you may want to consider delaying your Step 2 CK examination until after you have
applied and interviewed for residency. For instance, if you have a 250 or 260 on Step 1
and you get a 240 on Step 2 CK, it makes you look bad. If you are applying in Internal
Medicine, or Psychiatry or Pediatrics, I do not think this helped you. If, however, you
got a 220 on Step 1 then the same grade of 240 makes you look better. However, if you
are applying to Ophthalmology, Dermatology, Orthopedics or a very competitive
specialty, you will need to establish high grades on both Step 1 and Step 2 CK to gain
credibility. The bottom line is, if you are a U.S. student with a high score on Step 1 and
do not absolutely need a great grade on Step 2 CK to get in, then why chance it? Wait
until February or March or April of your fourth year when you are past the application
Residency and USMLE
Here’s another frequently asked question: How late can I take Step 2 CK and still be
competitive in the Match? The Electronic Residency Application Service (ERAS)
opens for applications in September. To be competitive, you should plan on having your
application complete by the end of September. You may think that the program directors
are sitting in their offices on opening day waiting for applications to come in over
ERAS so they can give out interviews. This is not true. Remember that many programs
will not consider an application “complete” until they have received the “Dean’s
letter.” Often, the Dean’s letter does not go out from the U.S. schools until October and
in some cases, November. However, if you are an international graduate, they will not
be waiting for the Dean’s letters to arrive since the majority of international schools do
not have this concept.
Do not take the exam before you are ready. You cannot retake Step 2 CK if you pass
with a poor grade. It is better to delay to prepare more than to take the exam illprepared.
If you think it is better to fail than to pass with a low grade, you are wrong. You cannot
hide the grade on previous attempts at Step 2 CK. It is better to delay your test than
to risk a lower grade. Unfortunately, it is true that if you wait to take Step 2 CK until
November or December, you will lose interview spots. However, if you take the test
prematurely and fail or pass with a minimal score, that grade will follow you around
through your entire application process. I would go so far as to say that it would be
better to sit out a year and fully prepare than take a chance on a failing or low
Students often wonder, “Is Step 1 or Step 2 CK more important to my future? Again, the
answer to this question may depend on your background. For U.S. graduates, Step 1 is
often the more important examination because that is the only test result that is submitted
with your ERAS application for residency. There is no intrinsic superiority of either
examination. Program directors will be split in their opinion on this question. Step 1
may be perceived as a “harder” examination, however, the pass rate for first-time U.S.
graduate test takers is about 93%. On the other hand, for many clinically oriented
specialties, the perception may be that your performance on a clinically oriented
examination such as Step 2 CK is more important than an examination more oriented to
basic sciences. For international graduates, Step 1 and Step 2 CK are generally of
equal importance since the program directors will see both grades.
What Do Program Directors Look For?
Program directors all agree on a few important criteria:
Where did you go to school?
Transcript and Dean’s letter for U.S. graduates
Visa status for international graduates
USMLE is the only worldwide, uniform measure across schools.
Other criteria such as research, publications, letters of recommendation, extracurricular
activities, and the personal statement are much harder to define and are not universally
valued. Some programs may highly prize research, some may not even look at your
publications until after you arrive for an interview. The personal statement often has no
value because it says nothing personal or original about you at all. Letters of
recommendation often all sound the same.
The reason that USMLE carries such importance is because it is the only worldwide
uniform measure across schools.. If you are a U.S. medical student, how do you prove
to a program director that you have greater value than a student applying from a school
with a very highly prized and famous name? Your USMLE score may be the only thing
that gives you an edge. If you are indeed from a school with a highly prized and famous
name, how do you prove that you are a better applicant than another candidate
from a similarly highly prized and famous name school? The answer is your
transcript and your USMLE score. If you are an international graduate, how do you
overcome the fact that you need a visa or perhaps you are applying as an older
graduate? The answer is the same: USMLE.
Is this fair? Is it right? The system is generally fair. The test taken by U.S. and
international graduates is the same. The test is not graded on a curve. That means that
theoretically, everyone taking the test on a particular day could get a 270. Whether or
not you think it’s right, one thing we know for sure is that the USMLE is of colossal
importance to your professional future.
Nothing makes a student more anxious than the programmatic requirement for “United
States Clinical Experience.” The truth is, unless you are at an international school that is
specifically geared to return you to the United States, you are often simply not going to
be able to get this U.S. experience. Do not worry!
Many, many future doctors obtain residency each year as international graduates without
U.S. clinical experience. A high score on Step 2 CK is also far more valuable than some
“fake” experience where you “hang around” an office. How is “observing” measurable?
What did you do there? I know you will get anxious about this. If you can get meaningful
U.S. experience, that’s great, however, a higher score on Step 2 CK is always
valuable. An “observership” or “externship” is of extremely inconclusive value.
How Does an Applicant Look to a Program Director?
After separating applicants into groups based on where they went to school and for
international graduates their visa status, the program director often has no readily
quantifiable way to assess the applicant. There is enormous pressure to make sure that
the pool he or she selects into the residency is highly qualified. Research,
observerships, and clinical grades are hard to measure. Is one school a harder grader
than another? Does one school practice grade inflation so that all the transcripts show
high grades? Does another school fail many students to prove they are serious? These
are all factors that may be considered. Take time to understand how your credentials
What If I Failed?
The best way to show that your failure on Step 2 CK is not an accurate measure of your
ability, knowledge, or intelligence is to pass with a very high score when you DO
pass. If you failed Step 1, there is a lot riding on your Step 2 CK grade. This book is
constructed to help you pass. Take your time. Study day and night. If you need more
practice, use question banks to prepare and assess your knowledge base. If necessary,
delay the exam until you are ready. Several years ago, the size of incoming classes in
United States medical schools started to increase after more than 30 years with the same
class size. In addition, many new schools are opening. This has enormous impact on
both U.S. and international graduates. In many specialties, simply being a U.S. graduate
automatically put you in the top half of the applicant pool. That is no longer true. The
incoming class size for U.S. schools will be increasing by several hundred every
year for the next several years. This will increase the competition for everyone trying
to get a good residency position.
United States medical students pass Step 2 CK at a rate of
approximately 93%, doctors of osteopathic medicine (DO) pass
at a rate of about 91%, and international graduates pass at a rate
of approximately 80%.
Your Final Step
You have worked very hard to get into medical school and to do well there. This is your
last step. A great score on Step 2 CK will mean that all of your professional dreams in
medicine are about to come true. Success on Step 2 CK will enormously influence what
specialty and at what kind of training program you match into. Your best bet is to invest
the time and energy required to ensure you get a high score.
Now is not the time to spare yourself. You can rest later. Now is the time to learn
everything in this book. Practice hard and remember that everything you are learning
here is medicine. It will help people. A high grade on Step 2 CK is not a phony
numerical statistic. What you are learning here will, with 100% certainty, help
someone. You will save lives. You will relieve suffering. You will do good for
humanity. It is with this emotional power that you should go forth to work hard and to
test the limits of your endurance. Do not spare yourself. Through your work, someone
will be saved and protected through what you learn here. These are not superfluous
What you learn here, through your heart and mind and the power of your hands will
protect those who suffer in their hour of need.
I wish you well in your quest. If you see what you are learning here as “as bunch of stuff
to cram in that you will forget,” you will not get as good a grade and the information
will quickly fade. If you can study knowing that a sick person that you have not yet met
is depending on you, their very life is depending on you, then you will absorb this
energy and make the studying you must do a sense of devotion.
We, you and I, commit ourselves at this moment to our sacred calling. To offer humanity
the best of our art, and to put the needs of others above our own needs, now and
Dr. Conrad Fischer
How to Use This Book
Congratulations! By studying for your Step 2 CK exam, you are well on your way to
becoming a doctor. This book contains information to help you perform well on the test
and target areas of study. Master the Boards USMLE Step 2 CKoffers a complete
outline for Step 2 CK preparation in a convenient, colorful format. For many medical
students, this book may be all the review you need, since your concurrent medical
training offers hands-on learning opportunities to reinforce the medical principles and
best practices tested on the USMLE.
Depending on how well you recall the topics in any given section of this book, you will
be able to customize your study appropriately. For example, if you find yourself not
recalling some major topics in the cardiology section, go back and review your primary
texts, and consider supplementing with question banks and practice questions. Some
students like to use a Master the Boards book before taking an in-depth live course, or
to recap the content after the course concludes. The content in this book is not identical
to the Kaplan Medical live classroom course books, but they work well to complement
This book contains exam-style questions and it offers the opportunity to test your
knowledge as you review. The answer explanations are another way to reinforce
knowledge. Therefore, this book can be used in tandem with Kaplan Medical’s USMLE
qBooks and question banks or any other case studies program.
The Master the Boards series is arranged by medical specialty. Each section contains:
Tips for recognizing incorrect answers
Mini cases with detailed answer explanations to reinforce learning
Full-color images of relevant items from the text
About the USMLE Step 2 CK
The USMLE Step 2 CK (Clinical Knowledge) is typically taken as the second test in a
series of three national certifying examinations that are necessary to obtain a license to
practice medicine in the United States. Step 2 CK is usually taken between the end of
the third year of medical school and the end of the fourth year. How is Step 2 CK
different than Step 1? Generally speaking, Step 2 CK is more clinically based than Step
1. Although there is no requirement to take Step 1 before Step 2 CK, this is the typical
sequence for U.S. graduates. According to the test maker, the questions on Step 2 CK
measure the ability to apply medical knowledge, skills, and understanding of clinical
science as they pertain to patient care (under supervision), with emphasis on health
promotion and disease prevention. Clinical Knowledge is one of two components of
Step 2; the other, Clinical Skills (CS), uses model patients to test the ability to perform
in a real clinical setting. Step 2 CK provides the foundation for the safe and effective
practice of medicine by future medical doctors.
Results of the USMLE are reported to medical licensing authorities in the United States
and its territories for use in granting the initial license to practice medicine. The
sponsors of the USMLE are the Federation of State Medical Boards (FSMB) and the
National Board of Medical Examiners (NBME).
About the USMLE Step 2 CK: Exam Blueprint
USMLE Step 2 CK is a computer-based test that consists of 355 questions taken over a
9-hour period. The test is divided into 8 blocks, each of which lasts 60 minutes. Once
you have completed a block or your 60 minutes has run out, you will not be able to go
back and review or change any of your work on that block. You will have 45 minutes of
break time, which is used to transition between blocks and for longer breaks that require
you to leave your seat (i.e., authorized breaks). The computer keeps track of your break
time. You must be sure not to exceed the 45 minutes or you will be penalized by having
any overage break time taken from the 60 minutes allotted for the last block of the test.
Structure of Step 2 CK Questions
The majority of Step 2 CK questions are single best answer (multiple-choice) questions
with a clinical vignette followed by a question. The basic structure is:
History of present illness
Possibly laboratory and radiologic tests
Here are the basic Step 2 CK question types, and consequently, the very structure
around which this book is created.
What is the most likely diagnosis?
What is the best initial diagnostic test?
What is the most accurate diagnostic test?
Which physical finding is most likely to be associated with this patient?
What is the best initial therapy?
When the question reads: “What is the most appropriate next step in the management of
this patient?” this can refer to either a test or a treatment. The phrase, most
appropriate next step can also be referred to as action, management, or simply what
should you do next? In all of these cases, the words step, action, do, or management
can mean either a test or a treatment.
The most frequently asked question on Step 2 CK is “What is the most likely
diagnosis?” As a result, many of the chapters in this book have a specific section
labeled “What is the most likely diagnosis?” One of the many unique attributes of the
Master the Boards format is that the diseases are presented with the specific goal of
answering these questions.
Sequential Questions and Matching
A smaller number of Step 2 CK questions are sequential. This means you can have
multiple questions following a single clinical story or vignette. Once you answer the
first question, you will not be able to go back to the original question. This is because
the second and third questions may give a clue to the answer to the first question. Some
of the questions in the sequence are essentially matching questions. This means there are
between 4 and 26 separate answers, and several cases may use the same answers. The
answers can be used once, more than once, or not at all.
The best preparation for Step 2 CK is to learn more medicine.
Depending on your situation, the registration process will differ. For the most accurate
and up-to-date information about registration and test day procedures, go to
http://www.usmle.org. At the time of publication, the registration fee is $590.
On the Day of the Exam
1. Arrive at the test center at least 30 minutes before your scheduled testing time to allow for check-in. If you arrive
late, you may not be permitted to take the exam. If you arrive more than 30 minutes after your scheduled test time,
you will not be permitted to take the exam.
2. You must bring your scheduling permit and an acceptable, unexpired form of identification with a recent (within
the last 10 years) photograph. Acceptable forms of identification include a passport, a driver’s license with
photograph, a national identity card, another type of government-issued identification with a recent photograph, or
an identification card issued by the Educational Commission for Foreign Medical Graduates (ECFMG).
Identification without a signature must be supported by a separate unexpired form of identification such as a credit
card with a signature.
U.S. medical graduates do not have to take Step 2 CK in order to
participate in the annual residency match. However, international
medical graduates must take Step 2 CK to be certified by the
Educational Commission for Foreign Medical Graduates. ECFMG
certification is required for international graduates in order to
participate in the match.
When you finish taking Step 2 CK, your answers are recorded for scoring. Your correct
answers are converted to a 3-digit score (as of publication, typically between 140 and
260) and a 2-digit score. Score reports and transcripts will show your 3-digit score and
either “Pass” or “Fail.” Score reports, not transcripts, also show how you did on certain
topics on the exam. This will help you assess your strengths and weaknesses as you
move forward with your studies.
A Passing Score
At the time of publication, the 3-digit passing score was 209. The 3-digit passing score
does and will increase over time. This is for a very simple reason: Current medical
students continue to improve their knowledge. The average score is currently 232. This
will also rise as students improve their knowledge.
You must answer between 60% and 70% of questions correctly in order to get a passing
score. There are always a number of new or experimental questions on each exam to
test new questions for future exams. Every attempt is made to keep the exam fair and to
allow the test to serve as an accurate measure of your knowledge level.
Introduction to Antibiotics
The organisms associated with particular diseases do not change over time, but the
antibiotics that treat the infections can change. The single most important thing for you to
learn in infectious diseases is the antibiotics that are associated with each group of
Principles of Answering Infectious Diseases Questions
1. The radiologic test is never “the most accurate test.”
2. Risk factors for an infection are not as important as the individual presentation.
3. Beta-lactam antibiotics have greater efficacy than other classes.
Beta-lactam Antibiotics: Penicillins, Cephalosporins, Carbapenems,
Penicillin (G, VK, benzathine): viridans group streptococci, Streptococcus pyogenes,
oral anaerobes, syphilis, Leptospira
Ampicillin and amoxicillin: cover the same organisms as penicillin, as well as E. coli,
Lyme disease, and a few other gram-negative bacilli.
Which of the following is the most accurate test for an infectious disease?
a. Protein level of fluid
c. IgM Levels
d. IgG Levels
e. G ram stain
f. Response to specific therapy
Answer: B. Culture.
Welcome to the Infectious Diseases section! When an organism can be grown in culture,
culture is definitely the most accurate diagnostic test for infectious diseases. This is true
of almost all bacteria and certainly for Staphylococcus, Streptococcus, and gramnegative bacilli. A few infectious disease agents do not grow in culture, such as those
that cause pneumocystis and syphilis. But for everything else, the accuracy of the test is
compared with the accuracy of culture.
Bacteria covered by amoxicillin:
H. influenzae, E. coli, Listeria, Proteus, and Salmonella.
They are the “best initial therapy” for:
• Otitis media
• Dental infection and endocarditis prophylaxis
• Lyme disease limited to rash, joint, or seventh cranial nerve involvement
• Urinary tract infection (UTI) in pregnant women
• Listeria monocytogenes
• Enterococcal infections
Penicillinase-resistant penicillins (PRPs): oxacillin, cloxacillin, dicloxacillin, and
These drugs are used to treat:
• Skin infections: cellulitis, impetigo, erysipelas
• Endocarditis, meningitis, and bacteremia from staphylococci
• Osteomyelitis and septic arthritis only when the organism is proven sensitive
They are not active against methicillin-resistant Staphylococcus aureus (MRSA) or
Methicillin sensitive or resistant really means oxacillin sensitive or
Methicillin is never the right answer. It causes renal failure from allergic interstitial
Piperacillin, ticarcillin, azlocillin, mezlocillin: These agents cover gram-negative
bacilli (e.g., E. coli, Proteus) from the large enterobacteriaciae group as well as
pseudomonads. They are the “best initial therapy” for:
• Cholecystitis and ascending cholangitis
• Hospital-acquired and ventilator-associated pneumonia
• Neutropenia and fever
Although these agents cover streptococci and anaerobes, they are not the answer when
the infection is exclusively from these single organisms. You would use a narrower
agent. They are nearly always used in combination with a beta-lactamase inhibitor such
as tazobactam or clavulanic acid.
Which of the following antibiotics will cover methicillin-resistant Staphylococcus aureus (MRSA)?
Answer: D. The only cephalosporin that will cover MRSA isceftaroline. None of the others covers MRSA. No
macrolide (azithromycin, clarithromycin, erythromycin) will cover MRSA. The medications that do cover MRSA are
vancomycin, daptomycin, ceftaroline, linezolid, tedizolid, dalbavancin, telavancin, and tigecycline.
The amount of cross-reaction between penicillin and cephalosporins is very small
(<3%). all cephalosporins, in every class, will cover group A, B, and C streptococci,
viridans group streptococci, E. coli, Klebsiella, and Proteus mirabilis.
Listeria, MRSA, and Enterococcus are resistant to all forms of