Explanations NBME 8
Explanations NBME 8
Patient with recent antibiotic usage develops severe diarrhea and abdominal
pain, which is most consistent with C. difficile infection
Key idea: C. difficile leads to diarrhea by producing two main toxins that lead
to enterocyte damage
Key idea: Toxic megacolon can be seen secondary to C. difficile infection and
ulcerative colitis (at least for NBME purposes)
Adenomyosis
Woman in her late 30s with previous pregnancies presents with progressive
menstrual pain and a soft, diffusely enlarged uterus most consistent with adenomyosis
(abnormal endometrial tissue within the uterine myometrium)
Key idea: Adenomyosis can lead to dysmenorrhea, heavy menstrual bleeding
and chronic pelvic pain
Key idea: Risk factors for adenomyosis includes age > 40, multiparity and/or
prior uterine surgery
Key idea: For the NBME exams, a diffusely enlarged uterus is either pregnancy
or adenomyosis, whereas an enlarged irregular uterus is consistent with fibroids
Young man who recently started treatment with haloperidol presents with rigidity,
neck rigidity and oculogyric crisis (eyes displaced upwards) most consistent
with acute dystonia
Key idea: Important to contrast with neuroleptic malignant syndrome, which
would lead to constellation of symptoms remembered with Malignant FEVER
(Myoglobinuria, Fever, Encephalopathy, Vitals unstable, increased CK Enzymes
and Rigidity)
Key idea: 4 main extrapyramidal effects of antipsychotic use, especially with
high potency antipsychotics such as haloperidol, are (1) Acute dystonia (2) Akathisia
(3) Parkinsonism (4) Tardive dyskinesia
Parenteral cefazolin
https://www.aa
fp.org/afp/2011/0301/p585.html
9. An otherwise healthy 37-year-old woman comes to the physician…
Endometrial biopsy
Arterial embolus
Older man with atrial fibrillation who is not on prophylactic anticoagulation who
presents with non-specific lethargy, hypotension, abdominal tenderness with guarding,
increased WBC count and surgical findings of dark necrotic bowel, most consistent with
an arterial embolus (most likely from the left atrial appendage in setting of atrial
fibrillation)
Adhesions would lead to small bowel obstruction (pain, distention, obstipation),
and C. difficile would lead to pseudomembrane image on NBME
Intraductal papilloma
Air embolism
Patient who has recently gone diving (which should be sounding off alarms about
decompression sickness (AKA “The bends”)) who presents with weakness and
neurologic symptoms concerning for decompression sickness
Key idea: Decompression sickness occurs when nitrogen dissolved in blood at
high pressures of deep sea diving forms bubbles as pressure decreases due to rapid
ascent to the surface and the bubbles lead to obstruction of blood vessels
Key idea: Potential symptoms of decompression sickness include signs similar
to stroke (due to blood vessel blockage), flu-like symptoms, and swelling/pain in
muscles and joints (remember association of decompression sickness with avascular
necrosis of bone)
Psychogenic polydipsia
Young male with excessive thirst and urination for 6 months who presents with
seizures found to have hypo-osmolar hyponatremia, most consistent with psychogenic
polydipsia
Key idea: This demographic is classically when signs/symptoms of
schizophrenia develop, and patients with schizophrenia are at increased risk for
psychogenic polydipsia
Key idea: If patient has hypo-osmolar hyponatremia and a urine osmolality <
100, then they almost certainly have psychogenic polydipsia or beer potomania
https://www.aa
fp.org/afp/2015/0301/p299.html
15. A 52-year-old man comes to the physician because of a 3-day…
Young patient with high-risk sexual behavior who presents with fever, malaise,
maculopapular rash over the palms and soles and diffuse lymphadenopathy, which is
most consistent with syphilis
Key idea: 3 major infectious causes of rash over the palms and soles can be
remembered with CaRS (Coxsackie A, Rickettsia Rickettsii (Rocky Mountain Spotted
Fever) and Syphilis)
Important to contrast syphilis and Rocky Mountain Spotted Fever, with syphilis
more commonly leading to a maculopapular rash and diffuse lymphadenopathy (with
epitrochlear lymphadenopathy basically being pathognomonic) and Rocky Mountain
spotted fever commonly leading to a purpuric rash that spreads from the hands/feet
to the trunk
17. A 16-year-old girl comes for a routine health maintenance…
Transesophageal echocardiography
16 year old girl with primary amenorrhea (girl without secondary sexual changes
by 13 or menarche by 15), short stature, and concern for coarctation of the aorta
(hypertension, upper extremity pulses > lower extremity pulses, systolic murmur), most
consistent with Turner syndrome
Coarctation of the aorta needs to be worked up with an echocardiography and
then operatively repaired
Propranolol
77-year old patient with a positive PPD skin test (>10 mm positive in patient living
in a high-risk facility) who is asymptomatic most consistent with latent tuberculosis
Key idea: 3 treatment options for latent tuberculosis are (1) Isoniazid and
rifapentine weekly for 3 months (2) Isoniazid for 6-9 months (3) Rifampin for 4
months
Key idea: Patients with diabetes, uremia, alcoholism, malnutrition, HIV,
pregnancy or epilepsy should always be given pyridoxine (vitamin B6) along with
isoniazid due to increased risk of B6-deficiency while on isoniazid
Key idea: PPD induration (NOT erythema) required for positivity depends upon
patient risk factors with >5 mm being positive in patients with significant
immunosuppression (HIV, organ transplant, immunosuppressant meds), recent
contact with patient with active TB or patients with CXR findings consistent with
TB // >10 mm being positive for patients from Tb endemic countries, IVDU,
residents of high-risk settings (prisons, nursing homes, homeless shelters, etc.),
children < 4 years old and patients working in mycobacterial labs // >15 mm in all
patients
Young otherwise healthy woman with short course of nausea and diarrhea has
persistent indirect hyperbilirubinemia on exam with otherwise normal LFTs, most
consistent with Gilbert’s syndrome (deficiency of serum glucuronosyltransferase such
that you cannot efficiently conjugate bilirubin)
Key idea: Prevalence of Gilbert’s syndrome is ~5-10%
Key idea: The two most common murmurs heard in setting of Marfan syndrome
include aortic regurgitation (early decrescendo diastolic murmur heard best at left/right
upper sternal border) and mitral valve prolapse (mid-systolic click followed by mid-to-
late systolic murmur of mitral regurgitation heard best at the apex)
Key idea: HOCM and MVP are the two murmurs that improve with increases in
preload (increased preload leads to less obstruction in HOCM and later MVP murmur
because the LV will be more stretched and the chordae tendinae will be more taut)
Intramuscular epinephrine
Atopic child (eczema, allergic rhinitis) who presents with severe respiratory
distress, hypotension, edema of the face and hands and subglottic narrowing on AP x-
ray, most consistent with anaphylactic shock
Although the history of respiratory distress and stridor in a patient without
childhood vaccinations should raise concern for epiglottitis (in which case we would
treat with intubation + antibiotics), this diagnosis would lead to sore throat, high fever
and drooling and would not as commonly lead to hypotension and would not lead to
edema of the face/hands or subglottic narrowing
Allograft rejection
Patient with recent liver transplant presents weeks later with fever, eosinophilia
(in a patient taking prednisone where we would otherwise expect low eosinophils),
elevated LFTs and a biopsy showing a mononuclear infiltrate with eosinophils in the
hepatic triads, consistent with allograft rejection
Key idea: Graft eosinophilia is a sensitive and specific marker of acute rejection
in liver allografts (https://www.ncbi.nlm.nih.gov/pubmed/9724472)
Sertraline
Child with pain/itching of the year with pain upon manipulation of the tinna,
most consistent with otitis externa
Otitis externa is most commonly treated with a topical antibiotic (ciprofloxacin
drops)
Pneumoconiosis
Elderly man with significant smoking history and occupational history of being a
coal miner who presents with clubbing and hypoxia with bilateral upper lobe masses
and areas of consolidation on chest x-ray most consistent with COPD and/or coal
workers’ pneumoconiosis
Key idea: Of the common pneumoconioses, the majority affect the upper lobes
(silicosis, coal workers’ lung, berylliosis) except for asbestosis (lower-lobe
predominant)
Tuberculosis can also lead to upper lobe opacities, but it would more commonly
lead to acute fever, night sweats and weight loss in a patient with exposure
Pneumothorax
A patient who likely came to ED with altered mental status in the setting of
benzodiazepine overdose is intubated and then becomes agitated, hypoxic, tachycardic
and hypotensive most concerning for a tension pneumothorax
Key idea: Trauma and mechanical ventilation are two major risk factors for
tension pneumothorax
Key idea: Ventilator would have high-pressure alarms in this setting because the
machine is likely trying to push the same amount of air into the lungs even though the
volume has been cut in half
Aspirin
Young healthy man who presents with chest pain and ST-elevation in an anterior
distribution after using crack cocaine, most consistent with cocaine-induced MI
Key idea: Cocaine induced MI treated the same way as atherosclerotic MI,
except that beta blockers are not used (due to theoretical risk of unopposed alpha-
agonism) and benzodiazepines are used
Key idea: Cocaine use is associated with myocardial infarction (due to spasm of
the coronary arteries) and aortic dissection (due to increased blood pressure), but this
presentation more consistent with pure MI because patient has normal BP in both arms
(although this is commonly seen in aortic dissections in real life, test writers often will
say blood pressures are unequal) and no tearing chest pain into the back
AIDS
27 year old patient with hepatitis B (which shares many risk factors with HIV
infection) presents with chronic weight loss and acute shortness of breath with cervical
lymphadenopathy, white plaques in the mouth (most consistent with thrush), relatively
low lymphocyte count and bilateral diffuse infiltrates on CXR most consistent
with Pneumocystis pneumonia in setting of HIV/AIDs
Key idea: Patient with HIV is considered to have progressed to AIDS when their
CD4 count drops below 200 or if they develop an AIDS-defining infection (such as PCP
pneumonia)
Elderly patient with recent stroke leading to residual right hemiparesis presents
with frequent urinary dribbling and filled bladder (palpable smooth mass in suprapubic
area), most consistent with neurogenic bladder complicated by overflow
incontinence
Note: Detrusor instability would lead to urgency incontinence and increased
vesicourethral angle associated with stress incontinence
Tourette disorder
72 year old patient with lung cancer presents with non-fatigable weakness
affecting the eyes and proximal muscles (hip extensors, eyes), autonomic symptoms
(dry mouth, constipation) and loss of deep tendon reflexes, most consistent
with Lambert-Eaton syndrome (which can be diagnosed with repetitive nerve
stimulation)
Myasthenia gravis: Associated with thymoma, oculobulbar weakness that
worsens with repeated use
Lambert-eaton syndrome: Associated with small cell lung cancer, proximal
muscle weakness that improves with repetitive use AND autonomic dysfunction and
decreased/absent deep tendon reflexes
Patient with small cell lung cancer (uniform, small round cells with dark nuclei),
which is often initially treated with chemotherapy followed by radiation and/or
surgery
Patient is young and has no signs of metastasis so palliative care isn’t
appropriate, hormone therapy most used for breast cancer and prostate cancer, and
surgical resection is NOT used in small cell lung cancer specifically (“the cells are too
small for the surgeon to see!”)
Young healthy woman presenting with abdominal pain relieved by stools, with
stool consistency being abnormal, all features of irritable bowel syndrome
Key idea: IBS is a diagnosis of exclusion that can lead to constipation and/or
diarrhea and is often associated with (1) pain related to defecation (2) change in
stool consistency (3) change in stool frequency
Detrusor hyperactivity
Patient with risk factors for spastic bladder (MS) has presentation consistent
with urgency incontinence (urge to void immediately with loss of urine before reaching
the bathroom at times), which is caused by detrusor hyperactivity/instability
Stress incontinence: Loss of urine with cough or increased abdominal
pressure, caused by urethral hypermobility or sphincter deficiency
Overflow incontinence: Incomplete emptying of bladder leading to leak with
overfilling; patient would have increased postvoid residual
Nonalcoholic steatohepatitis
Young obese woman with no alcohol history found to have dyslipidemia and
mildly elevated LFTs most consistent with non-alcoholic steatohepatitis
Patients use of acetaminophen not sufficient to cause liver damage (more
commonly leads to fulminant liver failure in patient with overdose), does not have other
signs of hemochromatosis (bronze diabetes, cardiomyopathy, etc.), LFTs incompatible
with primary biliary cirrhosis (would be cholestatic with direct hyperbilirubinemia and alk
phos >> ALT/AST, and no signs of hepatitis on labs (negative HCV antibody and
negative HB surface antigen)
Key idea: NASH has overtaken alcoholic steatohepatitis as most common cause
of chronic liver disease and cirrhosis in certain countries
Cardiac tamponade
Key idea: 2 most important risk factors for Alzheimer’s is (1) Increased age (2)
Family history of early-onset dementia (often due to mutation in Amyloid precursor
protein or presinilin-1/2)
Key idea: Early-onset Alzheimer’s defined by symptoms appearing age 65 or
younger
Echocardiography
Young man with recent URI presents with sharp substernal chest pain, fever and
ECG with diffuse ST elevations and PR depressions most consistent with viral
pericarditis which can be diagnosed with echocardiography because it is often
complicated by pericardial effusion
Exam section 2:
Young man presents with altered mental status found to have a severe anion-
gap metabolic acidosis (142 – 102 – 12 = 28 > 12), with exogenous ingestion of an
organic acid being the only answer that corresponds with this acid-base disturbance
Negative ketones in urine –> Rules out DKA
Excessive loss of bicarbonate = Type 2 renal tubular acidosis (non-anion gap
metabolic acidosis)
Young previously healthy man with recent behavioral changes who presents with
severe chest pain, signs of autonomic overactivity (tachycardia, hypertension,
diaphoresis), rapid and pressured speech and ST-elevations on ECG, most consistent
with substance-induced MI (most likely cocaine)
Key idea: In contrast to bipolar disorder (which can also lead to pressured
speech, increased activity, etc.), substance-induced behavioral changes will also lead
to pure physical manifestations of autonomic overactivity (hypertension,
tachycardia, mydriasis, etc.)
Penicillin G benzathine
Young woman with unsafe sexual practices and IVDU presents with fever,
generalized lymphadenopathy and a diffuse maculopapular rash involving the palms
and soles, most consistent with syphilis
Key idea: First-line treatment for syphilis is intramuscular penicillin G, with an
alternative being doxycycline in patients with severe penicillin allergy
Key idea: Pregnant women with penicillin allergy should undergo penicillin
desensitization because they are not allowed to use doxycycline (risk of teeth and
bone abnormalities in baby)
Small-bowel stricture
Young man with a chronic history of Crohn disease who presents with symptoms
of a small bowel obstruction (distention, abdominal pain, high-pitched bowel sounds,
nausea/vomiting, obstipation and air-fluid levels on small intestine), most concerning for
a small-bowel stricture
Key idea: Crohn disease leads to transmural inflammation, and can therefore
lead to strictures, fistulas, etc.
Young patient on an OCP (leads to increased risk of clotting) with recent history
of femur fracture and being bed-bound who presents with dyspnea, pleuritic chest pain,
hypoxia and a new small pleural effusion most consistent with pulmonary embolism
Virchow’s triad for DVT/PE: (1) Hypercoagulability (2) Stasis (3) Endothelial
injury
Pancreatic enzyme
Newborn with family history of cystic fibrosis who has presentation consistent
with meconium ileus (failure to pass meconium, bilious vomiting, inspissated tar-like
meconium, etc.), and therefore should be treated with pancreatic enzyme
Key idea: Cystic fibrosis leads to fat malabsorption because pancreatic enzymes
have trouble reaching the GI tract, so patients can benefit from pancreatic enzyme
Middle-aged man with HIV presents with progressive pain and difficulty with
bowel movements with a DRE showing a palpable mass in the anal canal with central
ulceration most consistent with a squamous cell carcinoma
Key idea: HPV-related squamous cell carcinomas of the cervix, anus and penis
are more commonly seen in HIV patients, which is why female patients with HIV should
receive annual pap smears (rather than every 3-5 years)
Blood: Trace / Protein: 1+ / RBC: 0-5 / WBC: >50 / Casts: None / Other: WBC
clumps
Young sexually active woman (high risk of UTI) who presents with systemic signs
of inflammation (fever) and is found to have dysuria, unilateral back pain and severe
CVA tenderness, most consistent with pyelonephritis
Key idea: 2 major causes of WBC casts/clumps include pyelonephritis and
Interstitial nephritis (analgesic nephropathy)
Patient with history of type 2 diabetes who has not been using medications
presents with nausea/vomiting and confusion found to have a glucose level of 890 and
a serum osmolality of 316, most consistent with Hyperosmolar hyperglycemic state
Key idea: Serum osmolality = (Na x 2) + (Glucose/18) + (BUN/2.6) +
(Ethanol/4.6)
Key idea: The hyponatremia is secondary to the hyperosmolar state, and
therefore is not the primary cause of confusion in this patient
Retrograde urethrography
Young man with significant trauma found to have signs of pelvic fracture (pelvic
pain with crepitus/tenderness over the pubis, x-ray findings) found to have a large
scrotal hematoma, concerning for a urethral injury
Key idea: Although classically a pelvic fracture would injure the membranous
portion of the urethra (leading to a high-riding prostate and blood at the urethral
meatus), it can also damage the bulbar (spongy) urethra and lead to blood
accumulation in the scrotum and blood at urethral meatus
Key idea: Retrograde urethrogram is the first test to perform in patients with
suspected urethral injury
Medulloblastoma
Young otherwise healthy woman with severe dermatomal (L5) back pain after
heavy lifting that increases with Valsalva and straight-leg raising, most consistent with
a lumbar radiculopathy
Key idea: Two main causes of back pain with a positive straight leg test are disc
herniation and osteophyte (same pathophysiology with spinal root compression)
Positive predictive value: Of the positive test results, how many actually had the
disease (dependent on disease prevalence)
Sensitivity: Of the patients with disease, how many had a positive test result
(independent of disease prevalence)
Fat embolism
Epstein-Barr virus
Young patient with high-risk sexual behaviors presents with acute fever, sore
throat, fatigue, tender/enlarged cervical lymph nodes, increased lymphocytes, and
mildly increased LFTs with a negative rapid strep test, most consistent
with infectious mononucleosis, which is caused by EBV > CMV
Diabetic ketoacidosis
Adolescent with history of weight loss despite normal appetite presents with
acute nausea, vomiting, abdominal pain, mental status changes and is found to be dry
on physican exam with labs consistent with an anion-gap metabolic acidosis (135 – 101
– 14 = 20 > 12) with an elevated glucose, most consistent with diabetic ketoacidosis
DKA: Glucose 250-500, anion-gap metabolic acidosis, ketones in urine, GI
symptoms predominate
Hyperosmolar hyperglycemic state: Glucose > 600, relatively normal acid-
base status, no ketones in urine, altered mental status predominates
Subclavian artery
Fluid restriction
Patient with small cell lung cancer develops hyponatremia = SIADH until proven
otherwise (basically confirmed with a urine osmolality > 100 and urine sodium > 40)
Mild hyponatremia symptoms (sodium>120, lethargy/forgetfulness): Fluid
restriction +/- salt tablets
Severe hyponatremia symptoms (sodium<120, seizures, coma): Hypertonic
(3%) saline
Elderly man with joint pain in his knees and DIP joints of the hand that are
worsened by use, most consistent with osteoarthritis
Key idea: The two main diseases that affect the DIP joints of the hand (at least
on NBME exams) are osteoarthritis and psoriatic arthritis
Cataracts
Elderly woman with trouble driving at night due to vision impairments related to
bright lights who also has yellowing of the lenses on physical exam, most consistent
with cataracts
Risk factors for cataracts: Advanced age, diabetes, corticosteroid use, smoking,
excessive alcohol use, excessive sunlight exposure, congenital disease (galactosemia,
etc.)
https://courses.
lumenlearning.com/epcc-austincc-ap1-2/chapter/divisions-of-the-autonomic-nervous-system/
25. A 9-year-old boy is brought to the physician by his mother…
Young man engaging in unprotected sex who presents with dysuria and scant
urethral discharge
Key idea: If testing finds only chlamydia, then treat with only azithromycin
Key idea: If testing finds gonorrhea or you are treating empirically, then patient
needs azithromycin + ceftriaxone
Cervical cancer
Pregnant woman with no prenatal care presents with painless vaginal bleeding
and a friable ulcer on the cervix, concerning for cervical cancer
Key idea: For the NBME exam, if a patient has no prenatal care, then they want
you to assume that the patient does not consistently engage in care and likely does not
get regular pap smears
Note: Fundal placenta excludes placenta previa as a cause (important cause to
consider in setting of painless 3rd trimester vaginal bleeding)
Young man who has been camping for 3 weeks who presents with
encephalopathy, fever/chills, headache and maculopapular rash involving the palms
and soles along with petechiae/purpura of the lower extremities, concerning for RMSF
Key idea: RMSF (along with many other tick-borne illnesses such as
Ehrlichiosis, Anaplasmosis, etc.) leads to leukopenia and thrombocytopenia
Key idea: Infectious rash over the palms and soles can be remembered with
mnemonic CaRS: Coxsackie A, Rickettsia Rickettsii, Syphilis
Patient who has never received vaccination against hepatitis B is stuck with a
needle by a patient with labs consistent with active hepatitis B infection, so patient
should receive both hepatitis B vaccination series and hep B immune globulin
Infections that need to be treated with immunoglobulin: Dangerous
infections To Be Healed Very Rapidly (Diphtheria, Tetanus, Botulism, Hepatitis
B, Varicella, Rabies
Middle aged patient with significant smoking history who is breathing with
pursed lips (“pink puffer” of emphysema) and has diffuse wheezes in all lung fields,
concerning for COPD
Aspiration of foreign body would only be acute, asthma would be episodic (not
chronic progressive), bronchiectasis would be less likely to lead to diffuse lung changes
and heart failure would lead to S4, elevated JVP, significant lower extremity edema, etc.
Systolic ejection murmur in the left sternal border consistent with pulmonic
stenosis (as seen in Tetralogy of Fallot) and history of becoming cyanotic while crying
also consistent with Tetralogy of Fallot
Key idea: Causes of early cyanosis from primary heart defects can be
remembered with mnemonic 1, 2, 3, 4 and 5 because it can be caused by (1)
persistent truncus arteriosus (1 vessel) (2) transposition of the great vessels (2
switched vessels) (3) Tricuspid atresia (Tri = 3) (4) Tetralogy of Fallot (Tetra = 4) (5)
Total anomalous pulmonary venous return (5 letters in name)
Key idea: Early cyanosis does NOT mean that patient needs to have cyanosis at
birth
Selection bias
Patient with severe neuromuscular weakness who remains prone without much
movement develops an ulcerative lesion on the back of their head, concerning for
a decubitus ulcer
Note: Atypical mycobacterial infection can lead to ulcerative, violaceous cervical
lymphadenopathy in children
95%
Specificity = In patients who do NOT have the disease, what proportion will test
NEGATIVE
Patient with severe retching/vomiting develops severe retrosternal pain and pain
in the chest with a new pleural effusion on the left, most consistent with Boerhaave
syndrome
Key idea: Severe retching can lead to Mallory-Weiss tear (severe hematemesis)
and Boerhaave syndrome (severe chest pain with extrapulmonary air)
Plantar fasciitis
Key idea: History of heel pain that is worst with first steps in morning and
pain with passive dorsiflexion of toes is classic for plantar fasciitis; plantar fasciitis
also commonly associated with bone spur on plantar surface of foot
Differential for heel pain: (1) Plantar fasciitis (2) Bone infection or metastasis
(constant pain that is worst at night) (3) Calcaneal stress fracture (worse with activity
and palpation) (4) Tarsal tunnel syndrome (percussion tenderness and paresthesias
over posterior tibial nerve in tarsal tunnel) (5) Achilles tendinopathy (pain/tenderness at
posterior heel with palpable thickening of tendon that can be reproduced with foot
dorsiflexion)
This is a classic presentation for a patient with coarctation of the aorta. When
they are first born, blood is able to get past the coarctation because blood flow through
the ductus arteriosus enters the aorta distal to the coarctation. When the ductus
arteriosus closes in the first week of life, the left side of the heart then sees a massive
increase in afterload, leading to heart failure
Lymphangitis
Patient with an inflammed area of the distal radius with red streaks extending
from the area towards the elbow, most consistent with lymphangitis
Key idea: Most common pathogens are MSSA and Group A strep, and therefore
empiric treatment is cephalexin
https://en.wikip
edia.org/wiki/Lymphangitis
40. A 16-year-old girl comes to the physician for a follow-up…
Supplemental oxygen
Ureteral ligation
Young woman with recent total abdominal hysterectomy who is anuric with drain
creatinine = serum creatinine, AKI and mild bilateral hydronephrosis consistent
with ureteral ligation/damage due to surgery
Key idea: Drain fluid creatinine: Serum creatinine ratio > 1 consistent with urine
leak
Key idea: Hysterectomy and other female GU operations are highly associated
with ureteral damage (especially in NBME exams)
Topical mupirocin
Child presents with a rash on her mouth and cheek with honey-colored crust,
most consistent with impetigo
Key idea: HSV infection can also present as a honey-color crusted rash on face,
but it will be limited to the orolabial region (would not involve the cheek)
45. A 2-hour-old female newborn has the onset of fever. She was born…
Exam section 3:
21-Hydroxylase
https://www.m
erckmanuals.com/professional/pediatrics/endocrine-disorders-in-children/congenital-adrenal-
hyperplasia-caused-by-21-hydroxylase-deficiency
3. A 25-year-old nurse comes to the physician 2 days after a PPD skin…
Chronic inflammation
Elderly woman with rheumatoid arthritis presents with pallor and is found to have
a microcytic anemia with a decreased TIBC (indicative of increased ferritin stores),
most consistent with anemia of chronic disease
Iron deficiency (microcytic anemia): Iron labs show low iron, increased TIBC and
decreased ferritin (often seen in young women due to menses and in older patient is
colon cancer until proven otherwise)
Lead poisoning (microcytic anemia): Patient with exposure who has abdominal
pain, neurologic symptoms, etc.
Key idea: While rheumatoid arthritis can be associated with anemia of chronic
disease, osteoarthritis is NOT associated with anemia of chronic disease
Postviral myocarditis
Patient with history of influenza-like illness ~1 month ago who presents with
acute dyspnea, fatigue, light-headedness, ECG changes and echo showing hypokinesis
with normal valves, most consistent with a postviral myocarditis
Key idea: On NBME exams, if a young patient presents with signs of cardiogenic
shock without trauma, a common cause is myocarditis
Acute constrictive pericarditis would be seen in patient with radiation to the
chest, open heart surgery or some other insult that would lead to fibrosis of the
pericardium
8. A 19-year-old man comes to the emergency department because he…
Dopamine
11. A 12-year-old boy has the sudden onset of vomiting and moderate…
Lidocaine therapy
Key idea: Anesthetic that is accidentally injected into the blood stream can lead
to systemic signs/symptoms (tingling, numbness, tinnitus, metallic taste,
tachycardia, hypertension, etc.)
Elderly man with known squamous cell carcinoma who presents with elevated
calcium and otherwise normal labs, most consistent with PTHrP production
Key idea: Squamous cell carcinoma, breast cancer, renal cell carcinoma,
ovarian cancer and bladder cancer are known for producing PTH-related peptide, which
has the same effects as PTH (increased calcium, decreased phosphate)
Key idea: If answer was metastases to bone (commonly seen in breast cancer,
multiple myeloma, prostate cancer) then patient would have back pain and/or imaging
with osteolytic changes
Key idea: Lymphoma leads to hypercalcemia by leading to increased vitamin D
levels
Clindamycin
Elderly woman with history of cerebral infarction who has aphasia and loss of
gag reflex who presents with respiratory distress found to have RLL consolidation, most
consistent with aspiration pneumonia
Key idea: Aspiration pneumonia caused by anaerobic organisms (because our
mouth and GI tract has anaerobes), so patient is often treated with clindamycin which
has good anaerobic coverage (other potential options are metronidazole or amoxicillin
+ clavulanate)
Achalasia
Young woman with difficulty swallowing and oropharyngeal dysphagia found to
have classic “bird-beak” barium swallow finding of achalasia
Histoplasmosis
32 year old man with nasal polyps, chronic cough that is progressive with
copious sputum production who has clubbing and obstructive PFT findings (FEV1:FVC
ratio < 70%) found to have Pseudomonas aeruginosa colonization most consistent
with bronchiectasis in the setting of cystic fibrosis
Key idea: Bronchiectasis and chronic bronchitis (type of COPD) are two
conditions most known for copious sputum production
Potential etiologies of bronchiectasis: (1) Congenital: Cystic fibrosis,
Kartagener’s (2) Chronic/prior infection: Aspergillosis, mycobacteria (3) Rheumatic
disease: Rheumatoid arthritis, Sjogren’s (4)
Immunodeficiency: Hypogammaglobulinemia (5) Airway obstruction: Cancer
Key idea: Bronchiectasis should be worked up with CF testing, PFTs, sputum
culture, immunoglobulin levels and high-resolution CT of the chest
Caudate nucleus
Young patient with a father who developed a tic and committed suicide in middle-
age who presents with progressive facial grimacing and signs of dementia, most
consistent with Huntington disease (which is due to atrophy of the caudate nucleus)
Key idea: Huntington disease leads to triad of (1) Chorea (2) Dementia (3)
Depression (and other psychosocial issues such as psychosis)
Atrophy of substantia nigra = Parkinson’s disease
There is a 95% probability that the difference between the two cure rates is
between 8% and 26%
Key idea: When we set alpha value to 5%, we are saying that there is a 5%
chance of committing a type 1 error, which is where NO difference exists between the
two treatments/groups/etc. but we do detect a difference (basically the chance that we
detect a difference when one does not exist)
23. A 17-month-old infant with sickle cell disease has a 1-day history…
Ceftriaxone, parenterally
Infant with sickle cell disease presenting with sepsis (fever, clear rhinorrhea,
lymphocytosis), which is most likely caused by Strep pneumo and can be effectively
treated with ceftriaxone
Key idea: Sickle cell disease leads to functional asplenia, which leads to
increased risk of encapsulated infections (SHiN: Strep
pneumo, Haemophilus influenzae, Neisseria meningitidus)
Key idea: Although daily penicillin prophylaxis decreases the risk of Strep
Pneumo infection, it does not completely eliminate the risk
Pin fixation
Obese adolescent who presents with atraumatic, afebrile groin pain and a limp
with decreased range of motion and imaging showing displacement of the femoral head
from the growth plate, most consistent with a slipped capital femoral epiphysis
(SCFE) which is treated with pin fixation to avoid avascular necrosis
Key idea: Hip problems (osteoarthritis, avascular necrosis of the femoral head,
etc.) often lead to groin symptoms
2 common causes of avascular necrosis in child: (1) Legg-Calve Perthes
disease: Commonly seen in males between 5-7 years old, X-ray often NORMAL,
Idiopathic (2) SCFE: Commonly seen in obese ~12 year old child, Diagnosed via
abnormal x-ray, Caused by epiphysis displacing relative to femoral neck and needs to
be corrected surgically
https://www.m
ountnittany.org/articles/healthsheets/7381
25. A 77-year-old man is brought to the physician by his family…
Elderly patient with significant smoking history who presents with cachexia
(secondary to decreased appetite), decreased interest in smoking, abnormal mental
status examination, slow speech, and cognitive dysfunction concerning for lung cancer
vs. major depressive disorder, but patient has a normal chest x-ray which is more
consistent with major depressive disorder and therefore patient should have suicide
risk assessment (performed in all patients with depression)
Key idea: Major depression leads to at least 5 of the depressed mood +
SIGECAPS symptoms for at least 2 weeks
Superficial thrombophlebitis
Middle-aged patient with smoking history who has developed tenderness,
induration, erythema and thickening in a linear distribution on the extremities,
most consistent with superficial thrombophlebitis in the setting of pancreatic
cancer
Key idea: Pancreatic cancer patient will almost always be a smoker in NBME
question stem and unique signs/symptoms associated with pancreatic cancer
include (1) Back pain + weight loss (2) Migratory thrombophlebitis (Trousseau
syndrome) (3) Obstructive jaundice with palpable, non-tender gallbladder
(Courvoisier sign) (4) Diabetes in a patient without other risk factors (older patient
who is losing weight but develops diabetes)
Lymphangitis would also lead to streaks, but would be less likely to lead to
thickening/induration and more likely to lead to fever/chills
Varicose veins can be sensitive, but are not often tender or erythematous
Graves disease
Diabetes mellitus
Heparin therapy
Normally the kidneys can handle phosphorous, but in setting of renal failure they
cannot and it can lead to build-up of phosphorous that can lead to a variety of
deleterious effects, such as metastatic calcification (which can increase risk of stroke,
heart attack, etc.) and weak bones (because phosphorous pulls calcium out of bones);
these complications are particularly important for kids because they progress
chronically over time
Elderly patient with significant sun exposure (landscaper, farmer, etc.) with an
ulcerated, shiny lesion on their chest most consistent with a squamous cell carcinoma
or basal cell carcinoma
Key idea: Concerning skin lesions should be fully excised with ~3 mm margins
unless the lesion is very large or in a location where complete excision may be
problematic (ear, face, etc.)
Family history
Key idea: Risk factors for asthma include (1) Family history of atopy (2)
Environmental exposures (second-hand smoke, pollution, etc.)
https://www.aa
fp.org/afp/2016/0301/p363.html
37. A 62-year-old man has dyspnea on exertion and a cough productive…
Patient with type 1 diabetes who presents with fever, headache and facial
swelling with mild ketoacidosis and sinus pathology on CT scan, most concerning
for Mucor infection
Key idea: Mucormycosis is most commonly seen in ketoacidotic diabetic
patients and/or neutropenic patients
Key idea: Diagnosis requires biopsy and culture of the sinus mucosa
because Aspergillus can less commonly lead to a similar presentation
Methotrexate therapy
Young woman with previously regular menses presents with a late menstrual
period, RLQ abdominal pain with adnexal tenderness, and elevated beta-hCG with a
complex adnexal mass on ultrasound, most consistent with uncomplicated ectopic
pregnancy
Uncomplicated ectopic pregnancy (no hemodynamic instability or signs of
rupture): Methotrexate
Complicated ectopic pregnancy (hemodynamic instability or signs of
rupture): Urgent surgical exploration
Child with resection of ileum (which is responsible for absorption of the ) who
presents with macrocytic anemia, most consistent with vitamin B12 deficiency
Key idea: To remember the sections of small intestine and pertinent nutrient
absorbed in each, use mnemonic Iron Fist Bro for Iron (duodenum), Folate (jejunum)
and B12 (ileum)
Key idea: Ileum also responsible for absorption of bile salts, which are
responsible for fat absorption and absorption of fat-soluble vitamins (A, D, E and
K)
Patient who had normal hearing up until 3 years ago who has had potential
barotrauma (snorkeling-related ear pain) and loud noises who has loss of high-
frequency noises, most consistent with noise-related hearing loss
Key idea: Elderly patients who have had chronic exposure to noise will first lose
high-frequency sounds (bilateral, symmetric sensorineural hearing loss), with
young patients with increased exposure to loud noises being able to lose the high-
frequency sounds due to destruction of hair cells at the cochlear base
Osteophytes
Uveitis
Child with atraumatic, progressive, bilateral knee pain with elevated ESR and
otherwise normal exam/labs, most concerning for initial presentation of systemic
juvenile idiopathic arthritis
Along with many other causes of autoimmune disease, SJIA is associated
with anterior uveitis
Key idea: Classic NBME presentation is a patient with daily spiking fevers
associated with a transient pink macular rash, along with signs of inflammation of labs
(leukocytosis, anemia, thrombocytosis, increased ESR/CRP)
Exam section 4:
Bupropion
Patient with signs of major depressive disorder (too severe of a presentation for
simple adjustment disorder), who should be treated with an anti-depressant, with
Bupropion being the only antidepressant listed
First-line antidepressants: SSRIs, SNRIs, Bupropion, Mirtazapine
Benefits of bupropion: Mild stimulant effects, patient with comorbid cigarette
use, helps patients with weight loss, favorable sexual side effect profile
Abruptio placentae
Placenta accreta
Young man with ulcerative colitis who presents with fatigue, dark urine, mild
jaundice, with a cholestatic pattern on LFTs (alk phos > ALT/AST), most consistent
with primary sclerosing cholangitis
Primary sclerosing cholangitis: Classically seen in middle-aged men with
ulcerative colitis, leads to beading of intra and extra-hepatic bile ducts on ERCP/MRCP,
who has positive p-ANCA and elevated IgM
Primary biliary cholangitis: Classically seen in a middle-aged woman with
other autoimmune diseases who has granulomas with lymphocytic infiltrate on
biopsy, positive anti-mitochondrial antibody and elevated IgM
Poststreptococcal glomerulonephritis
Young child who had strep throat 2 weeks ago who presents with periorbital
edema, gross hematuria, proteinuria and RBC casts (consistent with
glomerulonephritis), most consistent with post-strep glomerulonephritis
Both IgA and PSGN can lead to gross hematuria associated with an upper URI,
with differences being (1) Acute PSGN: Seen 2-4 weeks after infection of pharynx or
skin, Seen in children (often age 6-10), leads to low complement levels, patient will
have subepithelial immune complex humps (2) IgA
nephropathy: Seen concurrently with respiratory or GI infection, more common in
young adult men (age 20-30), complement levels unaffected, patient will have IgA-
based deposits in mesangium
Key idea: Treating strep throat will reduce risk of rheumatic fever, but does
not reduce risk of post-strep glomerulonephritis
Ectopic pregnancy
Reassurance
Oral acyclovir
Middle-aged woman who presents with a vesicular, dermatomal rash with severe
burning over the area, most consistent with herpes zoster
Key idea: Oral and IV acyclovir are equally effective in treating herpes zoster, so
in this patient who does is going to be treated as an outpatient we would use oral
acyclovir
Septic arthritis
Child with refusal to bear weight, fever, leukocytosis and increased ESR,
consistent with septic arthritis
Septic arthritis: Leads to fever, ill-appearance, leukocytosis, failure to bear
weight, synovial fluid WBC > 50,000 with positive gram stain and culture, treated
with draining joint space + antibiotics
Transient synovitis: Patient will be afebrile, well-appearing between 2-6
years old, often had a previous viral URI, ability to bear weight, normal ESR, WBC
count and synovial fluid analysis, condition is self-limited
Surgical debridement
Middle-aged man with myasthenia gravis presenting with marked bilateral ptosis,
progressive lethargy and decreased breath sounds (all of which point to a myasthenic
crisis that would lead to respiratory insufficiency and CO2 retention), who has acid-base
findings of acidemia with increased PCO2 and normal HCO3, consistent with
an uncompensated respiratory acidosis
Key idea: If patient had chronic respiratory failure, HCO3 would be elevated
because it would have had time to compensate over time
Hypertension
Patient with Cushing’s triad (bradycardia, hypertension and irregular respirations)
which is a sign of elevated intracranial pressure with a CT scan showing a high-
density peri-ventricular hemorrhage, most consistent with a hypertensive bleed
Key idea: Common causes of brain bleeds include trauma, hypertension and
cerebral amyloid angiography
Toxic megacolon
Young patient with concern for IBD (increased stool frequency, signs of
inflammation [fatigue, weight loss], bloody stools) who presents with ill-appearance,
fever, hypotension, abdominal distention and an X-ray showing dilated transverse
colon, consistent with toxic megacolon in setting of ulcerative colitis
Key idea: Toxic megacolon associated with ulcerative colitis and C. diff colitis
Colonic pseudo-obstruction often seen in elderly patient who is post-op and/or
received opiates, diverticulitis leads to LLQ pain in an elderly patient, and ischemic
colitis leads to “pain out of proportion” in a patient with risk factors (atrial fibrillation,
endocarditis, etc.)
Trichophyton rubrum
Teenage wrestler (wrestler should always make you think of tinea infection!) who
has an erythematous, scaly, pruritic, annular rash with raised-edges most
consistent with tinea corporis
The most common dermatophyte organisms include Trichophyton,
Microsporum, and Epidermophyton
Staphylococcus aureus
The aneurysm should not be repaired because of the patient’s poor prognosis
Elderly man with imaging showing metastatic pancreatic cancer also found to
have a stable abdominal aortic aneurysm
Median survival of metastatic pancreatic cancer is 3-6 months, so the patient
would most likely die from cancer before having any negative effects from the
aneurysm, so repair of aneurysm has risks > benefits for this specific patient
Indications for abdominal aorta aneurysm repair in healthy patient: (1) > 5.5
cm in diameter (2) expansion of at least 0.5 cm in 6 months and/or 1 cm per year (3)
symptomatic (abdominal pain, flank pain, limb ischemia)
Chlamydia trachomatis infection
Young woman with suspected UTI who has symptoms that are refractory to 2
courses of antibiotics and urethral tenderness on physicial exam, most consistent
with urethritis which is most commonly caused by N. Gonorrhea or Chlamydia
trachomatis
Key idea: On the NBME, when it says that a woman is sexually active and uses
oral contraception, that means that they do not need condoms and are at increased risk
for STIs
Key idea: Empiric urethritis treated with azithromycin + ceftriaxone, gonorrhea
positive only treated with azithromycin + ceftriaxone and chlamydia positive only treated
with azithromycin only
Renovascular hypertension
Switch to insulin
Pregnant patient with type 2 diabetes with signs of poorly controlled blood
glucose while on metformin, therefore requiring step-up in therapy to include insulin
Target blood glucose levels in gestational diabetes mellitus are fasting glucose
< 95, 1-hour postprandial glucose < 140 and 2-hour postprandial glucose < 120
Key idea: Treatment options in gestational diabetes are (1st-line) Dietary
modification (2nd-line) Insulin, metformin
Blighted ovum
29. A 66-year-old woman has had lower abdominal pain and fullness…
Diverticulitis
Spinal stenosis
Pain in the hips/thighs that is exacerbated by walking and improves with leaning
forward with normal posterior tibial pulses, most consistent with pseudoclaudication
due to spinal stenosis
Claudication: Patient will have risk factors for peripheral vascular disease
(diabetes, HTN, smoking, etc.), reduced lower extremity pulses, reduced lower
extremity temperature, pain classically in the calves, reduced hair on legs
Pseudo-claudication (spinal stenosis): Positional (improves with flexion),
classically affects buttocks and thighs, may be associated with back pain
Peripheral vasodilation
Elderly nursing home patient presents with altered mental status, fever,
hypotension, warm extremities and a positive urinalysis (pyuria if >10 WBC/hpf), most
consistent with urosepsis (infection leading to peripheral vasodilation and distributive
shock)
Key idea: Distributive shock (anaphylaxis, sepsis, CNS injury) is the only type
that will lead to warm and dry skin
Key idea: Patient needs to have symptoms in order to be diagnosed with UTI >
Asymptomatic bacteriuria in the setting of a positive urinalysis, but in addition to dysuria
and suprapubic tenderness, altered mental status is often attributed to UTI and
considered a symptom
Zinc
Newborn who has trouble swallowing and handling secretions, most consistent
with a suspected tracheoesophageal fistula which can be tested by passing an NG
tube
Drain cleaner
Normal thymus
Thymus is normal in children < 3 years of age and commonly leads to “sail
sign” due to triangular shape
https://www.sli
deshare.net/airwave12/chest-x-ray-positioning
38. A 22-year-old woman has had heavy menstrual bleeding and easy…
Previously healthy young woman who presents with heavy menstrual bleeding
and easy bruisability found to have thrombocytopenia with bone marrow aspirate
showing increased number of megakaryocytes, with platelet count responsive to
prednisone, most consistent with idiopathic thrombocytopenia
Key idea: Immune thrombocytopenia caused by platelet antibodies and is often
associated with a preceding viral infection
Impaired platelet production = Aplastic anemia = Pancytopenia
Middle-aged man found to have elevated blood pressure for the first time, and
therefore should be initially managed with a trial of lifestyle modifications
A previously healthy young man with recent life stressors who presents with
sudden onset of blindness in one eye with a completely normal physical exam (including
tests demonstrating that he can in fact see out of that eye), most consistent
with conversion disorder
Testing will often involve a neurologist and psychiatrist
Polysomnography
Medical emancipation: “Sex, drugs and rock and roll” = STIs, pregnancy
care, or contraception // Mental healthy and addiction services // Emergency care
Legal emancipation: Parent, married, in the military, high school graduate,
financially independent (i.e. lives on their own)
Elderly patient who presents with short episodes of left-sided weakness and
right-sided blindness, consistent with embolization from an unstable plaque in
the RIGHT carotid artery
Key idea: Amaurosis fugax = Episodic, temporary loss of vision often in one eye
= carotid artery atherosclerosis (at least on NBME exams) = carotid duplex
ultrasonography
Unable to access audio, but patient has classic symptoms of a URI (fever, cough,
rhinorrhea) and likely normal heart sounds (or a soft systolic ejection murmur)