Examkin

All practice questions

1849 questions

All types8,270Multiple choice4,249Multiple select325Numeric160Matching1,849Ordering1,687
Question 521Question →

For each pediatric patient presented below, select the most appropriate routine preventive care intervention or immunization milestone recommended for their specific age according to standard pediatric guidelines.

Click a left item, then click its matching right item

Items

Newborn infant in the nursery prior to hospital discharge
12-month-old toddler presenting for a routine well-child visit
18-month-old toddler presenting for a routine well-child visit
11-year-old adolescent presenting for a routine well-adolescent visit

Matches

Show answer & explanation

Answer

Newborns receive the Hepatitis B vaccine; 12-month-olds receive their first MMR and Varicella vaccines; 18-month-olds undergo routine autism screening; and 11-year-olds receive Tdap, MenACWY, and HPV vaccines.
The Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP) establish a standardized schedule for childhood immunizations and preventive screenings. Birth involves the Hepatitis B vaccine. The 12-month visit is a major milestone for initiating live vaccines (MMR, Varicella). The 18-month visit includes targeted, formal autism screening. The 11-year visit transitions the patient to adolescent care with Tdap, MenACWY, and HPV vaccines.

Step-by-Step Solution

1
Identify the standard preventive care intervention for a newborn infant.
The Hepatitis B vaccine is the hallmark routine immunization given at birth.
This establishes early immunity and prevents perinatal transmission of the virus.
2
Determine the critical interventions scheduled for the 12-month visit.
Live vaccines (MMR and Varicella) are initiated at 12 months.
Circulating maternal antibodies wane by 12 months, allowing the child's immune system to mount an effective response to live vaccines.
3
Recall the specific developmental screening required at 18 months of age.
Autism-specific screening is routinely performed at 18 and 24 months.
Early detection of autism spectrum disorder significantly improves long-term developmental outcomes through early intervention.
4
Identify the adolescent vaccine bundle typically administered at 11 to 12 years of age.
The Tdap booster, MenACWY, and HPV vaccines are administered.
These vaccines provide protection against pertussis, meningococcal meningitis, and HPV-related cancers during adolescence and adulthood.

Key Concept

Routine pediatric preventive care schedule, including indicated immunizations and targeted developmental screening milestones.
Question 522Question →

Review the following clinical vignettes describing patients who are experiencing complications related to underlying malignancies. Match each patient's clinical presentation with the primary pathophysiologic mechanism responsible for their symptoms.

Click a left item, then click its matching right item

Items

A 68-year-old man with a newly discovered right hilar mass presents with proximal muscle weakness that transiently improves with repetitive movement, accompanied by dry mouth and absent deep tendon reflexes.
A 55-year-old woman with a history of treated breast cancer presents with subacute, rapidly progressive truncal ataxia, dysarthria, and multidirectional nystagmus. Brain magnetic resonance imaging reveals no intracranial metastases.
A 42-year-old man with bulky mediastinal lymphadenopathy, fever, and drenching night sweats develops anasarca. Laboratory studies show a serum albumin of 2.1 g/dL and a 24-hour urine protein of 5.2 g.
A 72-year-old man with an apical lung mass and a 50-pack-year smoking history presents with confusion, polyuria, and abdominal pain. Laboratory evaluation reveals a serum calcium of 14.2 mg/dL and an intact parathyroid hormone of 5 pg/mL.

Matches

Show answer & explanation

Answer

Lambert-Eaton syndrome (hilar mass) matches with antibodies against presynaptic calcium channels. Paraneoplastic cerebellar degeneration (breast cancer) matches with immune destruction of Purkinje cells. Minimal change disease (mediastinal mass/Hodgkin lymphoma) matches with cytokine-mediated foot process effacement. Humoral hypercalcemia of malignancy (apical lung mass) matches with ectopic PTHrP secretion.
Each clinical vignette provides a classic presentation of a distinct paraneoplastic syndrome. The first is Lambert-Eaton myasthenic syndrome (LEMS) caused by anti-calcium channel antibodies. The second is paraneoplastic cerebellar degeneration caused by anti-Purkinje cell antibodies. The third is minimal change disease secondary to Hodgkin lymphoma, caused by cytokine-induced podocyte injury. The fourth is humoral hypercalcemia of malignancy caused by tumor secretion of PTHrP.

Step-by-Step Solution

1
Analyze the first vignette to identify the syndrome and its underlying mechanism.
The combination of a central lung mass, proximal muscle weakness improving with use, and autonomic dysfunction indicates Lambert-Eaton myasthenic syndrome, caused by antibodies against presynaptic voltage-gated calcium channels.
Recognizing the classic triad of LEMS and its association with small cell lung cancer is required to identify the molecular mechanism.
2
Analyze the second vignette to identify the syndrome and its underlying mechanism.
Subacute ataxia in a breast cancer patient with a negative brain MRI points to paraneoplastic cerebellar degeneration, which is driven by onconeural antibodies (such as anti-Yo) destroying Purkinje cells.
Ruling out brain metastasis is crucial; the subacute cerebellar presentation in breast cancer is a classic paraneoplastic neurological syndrome.
3
Analyze the third vignette to identify the syndrome and its underlying mechanism.
Mediastinal lymphadenopathy with B symptoms implies Hodgkin lymphoma, and new-onset nephrotic syndrome in this context is almost always minimal change disease caused by T-cell cytokine release effacing podocyte foot processes.
Linking specific malignancies with their associated paraneoplastic glomerulopathies allows identification of the correct pathophysiology.
4
Analyze the fourth vignette to identify the syndrome and its underlying mechanism.
Severe hypercalcemia with suppressed PTH in a smoker with a lung mass indicates squamous cell carcinoma secreting PTH-related peptide (PTHrP), which activates PTH1 receptors.
Differentiating PTH-mediated hypercalcemia from PTHrP-mediated hypercalcemia is essential in oncologic emergencies.

Key Concept

Paraneoplastic syndromes possess specific pathophysiologic mechanisms that must be correlated with their associated underlying malignancies and varied clinical presentations.
Question 523Question →

Match each specific autoantibody profile with its most strongly associated rheumatologic condition.

Click a left item, then click its matching right item

Items

Anti-double-stranded DNA (anti-dsDNA)
Anti-centromere antibody
Anti-Jo-1 antibody
Anti-cyclic citrullinated peptide (anti-CCP)

Matches

Show answer & explanation

Answer

The correct pairings are: Anti-dsDNA matches with Systemic lupus erythematosus (SLE); Anti-centromere matches with Limited cutaneous systemic sclerosis; Anti-Jo-1 matches with Polymyositis / Dermatomyositis; Anti-CCP matches with Rheumatoid arthritis.
Each autoantibody listed has a distinct, classic disease association commonly tested on the USMLE. Anti-dsDNA is specific for SLE, anti-centromere for limited systemic sclerosis, anti-Jo-1 for inflammatory myopathies, and anti-CCP for rheumatoid arthritis. Recognizing these fundamental associations is essential for diagnosing systemic autoimmune disorders.

Step-by-Step Solution

1
Identify the target disease for anti-dsDNA.
Systemic lupus erythematosus (SLE).
Anti-dsDNA is a classic, highly specific diagnostic marker for SLE.
2
Identify the target disease for anti-centromere antibodies.
Limited cutaneous systemic sclerosis.
This antibody is uniquely linked to the limited cutaneous subtype of scleroderma.
3
Identify the target disease for anti-Jo-1 antibodies.
Polymyositis / Dermatomyositis.
Anti-Jo-1 targets histidyl-tRNA synthetase and is classically seen in these inflammatory myopathies.
4
Identify the target disease for anti-CCP.
Rheumatoid arthritis.
Anti-CCP is the most specific serologic test available for diagnosing rheumatoid arthritis.

Key Concept

Serologic autoantibody profiles in specific rheumatologic diseases
Question 524Question →

Accurate assessment of developmental domains is critical for identifying delays that warrant early intervention. Match each of the following documented developmental profiles to the chronological age at which a typically developing child is expected to achieve these specific milestones.

Click a left item, then click its matching right item

Items

Profile: Uses a spoon with some spilling, stacks 4 blocks, walks up stairs with one hand held, and speaks approximately 15 words.
Profile: Hops on one foot, copies a cross, engages in cooperative play, and speech is completely intelligible to strangers.
Profile: Copies a triangle, skips with alternating feet, draws a person with 6 distinct body parts, and dresses independently.
Profile: Rides a tricycle, copies a circle, speaks in 3-word sentences, and begins taking turns during play.
Profile: Sits with pelvic support (tripod position), transfers objects between hands, rolls from back to front, and babbles using consonants.

Matches

Show answer & explanation

Answer

The 18-month profile stacks 4 blocks; the 4-year profile hops and copies a cross; the 5-year profile skips and copies a triangle; the 3-year profile rides a tricycle; and the 6-month profile sits with support.
Each chronological age corresponds strictly to a classic constellation of gross motor, fine motor, language, and social milestones. Recognizing the synergistic development across all four domains allows for accurate age matching.

Step-by-Step Solution

1
Analyze the gross motor milestones for each clinical description to narrow down the age category (e.g., sitting vs. tricycle vs. hopping vs. skipping).
Identified the general age ranges for each of the five profiles.
Gross motor skills follow a highly predictable chronological sequence in the first five years of life.
2
Evaluate fine motor skills to confirm the exact age, particularly noting the progression of drawing shapes (circle vs. cross vs. triangle) and block stacking.
Differentiated precisely between the 3-year, 4-year, and 5-year profiles, as well as the 18-month profile.
Fine motor skills provide precise age differentiation in toddler and preschool years where gross motor differences might overlap.
3
Correlate language and social milestones with the motor findings to verify the final pairing.
All 5 clinical presentations successfully matched to their exact chronological ages.
A comprehensive developmental assessment requires all four domains (gross motor, fine motor, language, social) to align chronologically.

Key Concept

Normal Pediatric Growth and Development Milestones
Estimated Time:2m 0s
Question 525Question →

During a community pediatric developmental screening initiative, a physician evaluates several healthy children. Match each child's observed clinical milestone constellation with their most likely chronological age.

Click a left item, then click its matching right item

Items

Child P: Walks independently, uses a mature two-finger pincer grasp, and consistently says one specific word other than 'mama' and 'dada'.
Child Q: Jumps in place with both feet, builds a tower of six cubes, and spontaneously combines two words into meaningful phrases.
Child R: Pedals a tricycle, accurately copies a drawn circle, and routinely speaks in three-word sentences.
Child S: Hops on one foot without losing balance, copies a cross on paper, and engages in cooperative group play.

Matches

Show answer & explanation

Answer

Child P matches to 12 months; Child Q matches to 24 months; Child R matches to 36 months; Child S matches to 48 months.
Pediatric milestones follow predictable sequential patterns. At 1 year, children walk and say their first distinct words. At 2 years, they jump, combine 2 words, and build small towers. At 3 years, they ride tricycles, draw circles, and speak in 3-word sentences. At 4 years, they hop, draw crosses, and engage in cooperative play.

Step-by-Step Solution

1
Analyze Child P's milestones (walking, mature pincer grasp, first word).
These are classic 1-year (12-month) milestones.
Independent ambulation, fine motor opposition (pincer), and the emergence of specific words outside of babbling occur around the first birthday.
2
Evaluate Child Q's milestones (jumping, 6-cube tower, 2-word phrases).
These align with 2-year (24-month) developmental milestones.
The clinical 'rule of 2s' applies here—2-word phrases, 2/4 speech intelligibility, and combining gross motor coordination for two-footed jumping.
3
Assess Child R's skills (tricycle, copying a circle, 3-word sentences).
These are standard 3-year (36-month) milestones.
The clinical 'rule of 3s' applies—3-wheel tricycle, 3-word sentences, and drawing a one-line closed shape (circle).
4
Review Child S's presentation (hopping, copying a cross, cooperative play).
This corresponds to 4-year (48-month) development.
Higher-level balance (hopping), drawing intersecting lines (cross), and complex social interactions (cooperative play rather than parallel play) define this age.

Key Concept

Normal pediatric developmental milestones across motor, language, and social domains
Question 526Question →

Match each clinical presentation of a common infectious disease with the most appropriate first-line pharmacotherapy.

Click a left item, then click its matching right item

Items

A 24-year-old woman with dysuria, urinary frequency, and suprapubic pain; urinalysis reveals nitrites and leukocyte esterase without systemic symptoms.
A 30-year-old man with an expanding, painless, target-like erythematous rash on his leg after a camping trip in Massachusetts.
A 19-year-old man with a painless, 1.5-cm indurated genital ulcer and bilateral firm, non-tender inguinal lymphadenopathy.
A 22-year-old woman with exudative pharyngitis, fever, tender anterior cervical adenopathy, absence of cough, and a positive rapid antigen detection test.

Matches

Show answer & explanation

Answer

The correct pairings match uncomplicated cystitis with oral nitrofurantoin, early localized Lyme disease with oral doxycycline, primary syphilis with intramuscular benzathine penicillin G, and confirmed Group A streptococcal pharyngitis with oral amoxicillin.
Each clinical scenario represents a highly classic, uncomplicated presentation of a common infection for which there is a clear, guideline-directed first-line therapy. Using narrow-spectrum agents ensures efficacy while adhering to strict antibiotic stewardship principles.

Step-by-Step Solution

1
Analyze the first presentation of dysuria and a positive urinalysis without systemic signs.
Identified as uncomplicated acute cystitis.
Oral nitrofurantoin provides excellent bladder concentration while sparing systemic flora, adhering to antibiotic stewardship.
2
Evaluate the patient with the target-like rash following outdoor tick exposure.
Recognized as erythema migrans, denoting early Lyme disease.
Oral doxycycline is the standard first-line treatment for tick-borne diseases like Lyme disease in non-pregnant adults.
3
Assess the patient with a painless genital ulcer and inguinal adenopathy.
Diagnosed as primary syphilis.
Intramuscular benzathine penicillin G is the evidence-based definitive therapy for early syphilis.
4
Review the pharyngitis case with a positive rapid antigen test.
Confirmed Group A streptococcal (GAS) pharyngitis.
Oral amoxicillin provides targeted, narrow-spectrum coverage appropriate for GAS infections.

Key Concept

First-line empiric and targeted antimicrobial therapy for common outpatient infections
Question 527Question →

For each of the following outpatient clinical scenarios, select the most appropriate initial targeted pharmacotherapy.

Click a left item, then click its matching right item

Items

A 60-year-old man presenting with acute onset of severe pain, swelling, and erythema in his right first metatarsophalangeal joint. He has a history of stage IV chronic kidney disease.
A 30-year-old woman at 12 weeks gestation presenting with an expanding annular erythematous rash with central clearing, two weeks after hiking in an endemic region.
A 45-year-old woman presenting with dysuria, urinary frequency, and suprapubic discomfort without fever or flank pain.
A 52-year-old man presenting with a 3-cm fluctuant skin abscess surrounded by erythema and a history of recurrent methicillin-resistant Staphylococcus aureus (MRSA) infections.

Matches

Show answer & explanation

Answer

Gout with CKD matches to oral prednisone. Pregnant Lyme disease matches to oral amoxicillin. Uncomplicated cystitis matches to oral nitrofurantoin. Purulent MRSA abscess matches to oral trimethoprim-sulfamethoxazole.
Each appropriate therapy accounts for the specific infectious organism or inflammatory process while actively avoiding major drug-condition interactions, such as teratogenicity in pregnancy and nephrotoxicity in advanced renal failure.

Step-by-Step Solution

1
Analyze the first scenario (gout flare) and identify the critical contraindication.
The patient has stage IV CKD, which contraindicates NSAIDs and colchicine.
Recognizing patient comorbidities is essential for safe medication selection.
2
Analyze the second scenario (early Lyme disease) and consider the patient's state.
The patient is pregnant, contraindicating the typical use of doxycycline.
Amoxicillin must be substituted to ensure fetal safety while effectively treating Borrelia burgdorferi.
3
Evaluate the third scenario (lower UTI).
The presentation is consistent with uncomplicated cystitis, for which nitrofurantoin is a standard first-line therapy.
Guidelines recommend nitrofurantoin, TMP-SMX, or fosfomycin to minimize collateral antimicrobial damage.
4
Assess the fourth scenario (skin abscess).
The patient is at high risk for MRSA, requiring targeted coverage with TMP-SMX.
Standard beta-lactams are ineffective against MRSA, necessitating agents like TMP-SMX, doxycycline, or clindamycin.

Key Concept

Selecting appropriate initial pharmacotherapy for common outpatient conditions by adapting to specific patient contraindications, such as pregnancy and renal impairment.
Question 528Question →

Match each clinical presentation of a suspected blood transfusion complication with its most likely diagnosis.

Click a left item, then click its matching right item

Items

A patient develops fevers, chills, and a transient temperature elevation 2 hours after a blood transfusion, with stable vital signs and no evidence of hemolysis.
A patient develops acute dyspnea, severe hypoxemia, and bilateral pulmonary infiltrates 4 hours after receiving fresh frozen plasma, with normal central venous pressure.
A patient with a history of reduced ejection fraction develops acute dyspnea, hypertension, tachycardia, and jugular venous distention shortly after receiving 2 units of packed red blood cells.
A patient immediately develops flank pain, fever, tachycardia, hypotension, and dark urine shortly after the initiation of a packed red blood cell transfusion.

Matches

Show answer & explanation

Answer

The presentations map to Febrile non-hemolytic transfusion reaction, TRALI, TACO, and Acute hemolytic transfusion reaction respectively based on the presence of hemolysis, respiratory compromise, and volume status.
Each clinical presentation contains classic distinguishing features for a specific transfusion complication. Hemodynamics, timeline, and the presence or absence of pulmonary edema or hemolysis are the defining diagnostic factors.

Step-by-Step Solution

1
Analyze the onset timing and vital signs for each clinical scenario.
Timing ranges from immediately after initiation to several hours post-transfusion, with differing degrees of hemodynamic stability.
Vital signs and symptom onset are the primary ways to stratify transfusion reactions.
2
Identify the reaction with purely inflammatory signs (isolated fever, rigors) and normal hemodynamics.
The first scenario is a febrile non-hemolytic transfusion reaction.
Cytokine accumulation during blood storage causes transient fevers without hemolysis or respiratory distress.
3
Differentiate the two conditions causing post-transfusion respiratory distress based on volume status.
The second scenario (normal CVP) is TRALI, whereas the third scenario (hypertension, JVD, low ejection fraction) is TACO.
TRALI is a noncardiogenic pulmonary edema, whereas TACO is a cardiogenic pulmonary edema driven by fluid overload.
4
Identify the catastrophic reaction occurring immediately upon transfusion initiation.
The fourth scenario is an acute hemolytic transfusion reaction.
ABO incompatibility leads to immediate complement activation, massive intravascular hemolysis (dark urine), shock, and flank pain.

Key Concept

Differentiating blood transfusion reactions by evaluating the onset timeline, hemodynamic stability, and distinguishing features such as volume status and hemolysis.
Question 529Question →

Match each clinical vignette describing a systemic or opportunistic infection with the most appropriate primary therapeutic management.

Click a left item, then click its matching right item

Items

A 38-year-old male with untreated HIV (CD4 count 30 cells/mm³) presents with 2 months of fever, significant weight loss, and hepatosplenomegaly. Bone marrow aspirate reveals narrow-based budding yeast cells enclosed within mononuclear phagocytes.
A 72-year-old male resident of Rhode Island presents with an acute febrile illness, profound fatigue, and dark urine. Peripheral smear reveals hemolytic anemia and atypical intraerythrocytic tetrad forms (Maltese crosses).
A 28-year-old immunocompetent female returning from an archaeological dig in the San Joaquin Valley develops a low-grade fever, dry cough, and painful subcutaneous erythematous nodules on her anterior shins. Chest radiograph demonstrates a focal pulmonary infiltrate.
A 64-year-old male renal allograft recipient presents with progressive confusion and a cavitary pulmonary infiltrate. Brain MRI reveals a ring-enhancing lesion. Stereotactic biopsy shows filamentous, branching, Gram-positive bacilli that are weakly acid-fast.
A 59-year-old female with poorly controlled type 2 diabetes mellitus presents with facial pain, proptosis, and a necrotic ulceration on the hard palate. Biopsy demonstrates broad, non-septate hyphae branching at right angles.

Matches

Show answer & explanation

Answer

The correct matches are: 1) Disseminated Histoplasmosis with liposomal amphotericin B followed by itraconazole; 2) Babesiosis with atovaquone and azithromycin; 3) Uncomplicated Coccidioidomycosis with observation and supportive care; 4) Disseminated Nocardiosis with high-dose trimethoprim-sulfamethoxazole; 5) Rhinocerebral Mucormycosis with emergent surgical debridement and liposomal amphotericin B.
Each clinical vignette provides pathognomonic clues to a specific infectious disease requiring a distinct management strategy. Disseminated histoplasmosis (intracellular yeast in macrophages) requires amphotericin B induction followed by itraconazole. Babesiosis (intraerythrocytic tetrads/Maltese crosses) is treated with atovaquone and azithromycin. Primary coccidioidomycosis in an immunocompetent host with erythema nodosum represents a self-limited infection that requires only observation. Nocardiosis (weakly acid-fast, branching Gram-positive rods causing brain abscesses in transplant recipients) is treated with prolonged high-dose trimethoprim-sulfamethoxazole. Finally, mucormycosis (broad, non-septate, right-angle branching hyphae in a diabetic patient) is an aggressive angioinvasive fungal infection that universally requires both emergent surgical debridement and liposomal amphotericin B.

Step-by-Step Solution

1
Analyze each clinical vignette to identify the specific pathogen based on epidemiology, host immune status, and microscopic characteristics.
The vignettes describe: 1) Histoplasma capsulatum, 2) Babesia microti, 3) Coccidioides immitis, 4) Nocardia species, and 5) Mucorales.
Accurate identification relies on synthesizing pathognomonic clues: intracellular yeast in a patient with AIDS, intraerythrocytic tetrads in a Northeast US resident, Valley fever with erythema nodosum, weakly acid-fast branching rods in a transplant recipient, and broad right-angle hyphae in a diabetic.
2
Determine the definitive guideline-directed management for each identified infection.
Identify the standard therapies: Histoplasmosis requires amphotericin B/itraconazole, Babesiosis requires atovaquone/azithromycin, mild Coccidioidomycosis requires observation, Nocardiosis requires trimethoprim-sulfamethoxazole, and Mucormycosis requires surgery and amphotericin B.
Matching the pathogen to its targeted therapy assesses understanding of antimicrobial stewardship, opportunistic infection management, and situations where surgical intervention or watchful waiting is indicated.
3
Pair the clinical vignettes with their corresponding therapeutic management strategies.
The pairs are logically connected based on the diagnostic and therapeutic reasoning in previous steps.
This confirms the ability to translate complex diagnostic data directly into clinical decision-making.

Key Concept

Identification and targeted management of severe and opportunistic infectious diseases based on distinct microbiological, epidemiological, and host immune factors.
Estimated Time:3m 0s
Question 530Question →

Match each clinical presentation with the most appropriate first-line targeted antimicrobial therapy.

Click a left item, then click its matching right item

Items

A 34-year-old man presenting with a deep puncture wound to the plantar surface of his foot after stepping on a rusty nail through a rubber-soled athletic shoe.
A 28-year-old veterinary technician presenting with a rapidly spreading, painful, erythematous wound infection on her hand 24 hours after a cat bite.
A 45-year-old woman presenting with high fever, myalgias, leukopenia, and thrombocytopenia one week after a tick bite, without any visible rash.
A 26-year-old pregnant woman in her third trimester presenting with acute fever; initial blood cultures grow a motile, non-spore-forming Gram-positive bacillus.
A 32-year-old man presenting with copious purulent urethral discharge; Gram stain of the exudate reveals abundant neutrophils containing Gram-negative intracellular diplococci.

Matches

Show answer & explanation

Answer

The correct pairings match the sneaker puncture to oral ciprofloxacin, the cat bite to oral amoxicillin-clavulanate, the tick-borne illness to oral doxycycline, the Listeria bacteremia to intravenous ampicillin, and the gonococcal urethritis to intramuscular ceftriaxone.
Each correct pair links a specific clinical infectious disease vignette with its guideline-directed medical therapy. Sneaker puncture wounds uniquely require anti-pseudomonal coverage (ciprofloxacin). Cat bites require Pasteurella and polymicrobial coverage (amoxicillin-clavulanate). Ehrlichiosis requires intracellular coverage (doxycycline). Listeriosis in pregnancy requires targeted coverage (ampicillin). Uncomplicated gonococcal urethritis requires a third-generation cephalosporin (ceftriaxone).

Step-by-Step Solution

1
Analyze each clinical vignette to identify the most likely etiologic organism based on the specific exposure or laboratory findings.
Identified Pseudomonas aeruginosa, Pasteurella multocida, Ehrlichia chaffeensis, Listeria monocytogenes, and Neisseria gonorrhoeae as the respective pathogens.
Identifying the specific high-risk organism is the critical prerequisite for selecting targeted antimicrobial therapy.
2
Apply current pharmacological guidelines to select the optimal first-line agent for each identified pathogen.
Matched each organism with its definitive, guideline-directed treatment.
Standardized infectious disease guidelines ensure maximum clinical efficacy while practicing antimicrobial stewardship.

Key Concept

Appropriate selection of targeted antimicrobial therapy based on specific pathogen exposures and clinical presentations.
Question 531Question →

Match each clinical presentation of a hypertensive emergency to the most appropriate initial targeted pharmacologic intervention. Assume all patients require immediate medical management.

Click a left item, then click its matching right item

Items

A 45-year-old woman with a history of diffuse skin thickening presents with a severe headache. Blood pressure is 215/115215/115 mm Hg. Laboratory studies show a serum creatinine of 2.82.8 mg/dL (baseline 0.80.8 mg/dL) and numerous schistocytes on a peripheral blood smear.
Emergency evaluation is requested for a 62-year-old man who developed sudden-onset, severe, tearing chest pain radiating to his interscapular region. Blood pressure is 210/120210/120 mm Hg in the right arm and 140/90140/90 mm Hg in the left arm. A decrescendo diastolic murmur is heard at the right upper sternal border.
Episodic severe headaches, profuse sweating, and palpitations are the primary complaints of a 38-year-old man. Blood pressure is 230/125230/125 mm Hg, and heart rate is 115115/min. He has a strong family history of medullary thyroid cancer and primary hyperparathyroidism.
Respiratory distress and severe shortness of breath acutely develop in a 68-year-old man with a history of coronary artery disease. He is using accessory muscles of respiration. Blood pressure is 205/115205/115 mm Hg. Auscultation reveals diffuse bilateral crackles and a third heart sound (S3).

Matches

Show answer & explanation

Answer

Scleroderma renal crisis is treated with oral captopril; acute aortic dissection requires intravenous esmolol; pheochromocytoma crisis requires intravenous phentolamine; and flash pulmonary edema is managed with intravenous nitroglycerin.
Correct management of hypertensive emergencies requires tailoring the antihypertensive choice to the patient's specific end-organ damage and underlying pathophysiology. Scleroderma renal crisis relies on RAAS blockade (captopril). Aortic dissection requires decreasing cardiac shear stress (esmolol). Pheochromocytoma demands immediate alpha-blockade to counteract circulating catecholamines (phentolamine). Flash pulmonary edema benefits from rapid preload reduction (nitroglycerin).

Step-by-Step Solution

1
Analyze the clinical vignettes to identify the specific type of hypertensive emergency.
Identified scleroderma renal crisis, acute aortic dissection, pheochromocytoma crisis, and flash pulmonary edema.
Each condition has a distinct pathophysiology driving the profound blood pressure elevation.
2
Select the pharmacologic agent that directly antagonizes the pathophysiologic mechanism of the identified emergency.
Matched captopril to RAAS hyperactivation, esmolol to high wall shear stress, phentolamine to catecholamine excess, and nitroglycerin to acute volume/pressure overload.
Generic blood pressure lowering is insufficient and can be harmful; therapy must be targeted to the underlying disease process.

Key Concept

Targeted pharmacotherapy for specific hypertensive emergencies based on underlying pathophysiology.
Question 532Question →

Match each clinical scenario describing a high-risk infectious exposure with the most appropriate post-exposure prophylaxis (PEP) or management strategy.

Click a left item, then click its matching right item

Items

A healthcare worker with a documented anti-HBs titer of <10 mIU/mL after one complete primary vaccination series sustains a percutaneous needlestick from an HBsAg-positive patient.
A spelunker who received a complete pre-exposure rabies vaccination series 4 years ago is bitten by a bat while exploring a cave.
A surgical resident sustains a deep scalpel laceration during an operation on an HIV-positive patient with an unknown viral load.
A 20-year-old woman taking combined oral contraceptives is a close household contact of a roommate recently diagnosed with Neisseria meningitidis meningitis.

Matches

Show answer & explanation

Answer

Match the HBV non-responder to HBIG + revaccination; the previously rabies-vaccinated patient to vaccine on days 0 and 3 only; the HIV occupational exposure to 28 days of 3-drug ART; and the oral contraceptive user exposed to meningococcus to ciprofloxacin or ceftriaxone.
Each high-risk exposure corresponds to a highly specific, evidence-based post-exposure protocol that accounts for prior host immunity, medication interactions, and occupational risk.

Step-by-Step Solution

1
Analyze the hepatitis B exposure scenario.
The worker is a documented non-responder to the first vaccine series and is exposed to a known positive source.
This determines the need for both immediate passive immunity (HBIG) and an attempt at developing active immunity (revaccination series).
2
Evaluate the rabies exposure scenario.
The patient has a history of a complete pre-exposure rabies vaccination series.
Prior vaccination alters the PEP protocol by eliminating the need for HRIG and reducing the active vaccine schedule to two doses (days 0 and 3).
3
Assess the HIV exposure.
The exposure is high-risk (deep laceration) from a known HIV-positive source.
Current guidelines mandate a full 3-drug regimen for 4 weeks for high-risk occupational exposures to HIV.
4
Review the meningococcal prophylaxis scenario.
The patient requires PEP but is actively taking oral contraceptives.
Rifampin induces CYP3A4, which can lead to contraceptive failure. An alternative agent like ciprofloxacin or ceftriaxone must be selected to avoid this drug-drug interaction.

Key Concept

Guideline-concordant post-exposure prophylaxis for specific high-yield occupational and environmental infectious exposures.
Estimated Time:2m 0s
Question 533Question →

Select the newly indicated universal screening test that corresponds to each pediatric patient attending their scheduled health maintenance visit according to current guidelines.

Click a left item, then click its matching right item

Items

A 12-month-old infant presenting for a routine health maintenance examination
An 18-month-old toddler presenting for a routine health maintenance examination
A 10-year-old child presenting for an annual physical examination
A 12-year-old adolescent presenting for a sports preparticipation evaluation

Matches

Show answer & explanation

Answer

The 12-month-old requires anemia screening; the 18-month-old requires autism screening; the 10-year-old requires dyslipidemia screening; and the 12-year-old requires depression screening.
Each specific screening intervention must be matched with its corresponding initiation age as mandated by routine pediatric health maintenance guidelines (e.g., AAP Bright Futures). Anemia is universally screened at 12 months, autism explicitly at 18 and 24 months, lipid profiles universally between 9-11 years, and depression annually starting at 12 years.

Step-by-Step Solution

1
Determine the unique screening requirement introduced at the 12-month milestone.
Anemia screening via hemoglobin or hematocrit is identified as universally required at 1 year of age.
This detects nutritional iron deficiency common during the transition to whole cow's milk.
2
Determine the specific developmental screening initiated at the 18-month visit.
Autism spectrum disorder screening is required.
Early detection of autism signs at 18 and 24 months significantly improves long-term neurodevelopmental outcomes through early intervention.
3
Identify the cardiovascular screening recommended for school-aged children.
Universal dyslipidemia screening is identified for the 9 to 11-year age bracket.
Early identification of familial hypercholesterolemia and other lipid disorders prevents premature cardiovascular disease.
4
Identify the behavioral health screening introduced at the onset of adolescence (12 years).
Major depressive disorder screening is selected.
Adolescence marks a significant increase in the incidence of depression, warranting routine annual screening starting at age 12.

Key Concept

Age-specific universal screening guidelines in pediatric preventive care.
Question 534Question →

A pediatric clinic is reviewing its protocols for vaccine safety and administration. Match each pediatric patient's clinical history to the corresponding vaccine contraindication or appropriate management step.

Click a left item, then click its matching right item

Items

A 2-month-old infant with a past medical history of intussusception
A 4-month-old infant who developed unexplained encephalopathy 3 days after receiving their 2-month immunizations
A 12-month-old child recently diagnosed with severe combined immunodeficiency (SCID)
A 6-month-old infant who experiences isolated hives after eating eggs

Matches

Show answer & explanation

Answer

The infant with intussusception matches with the rotavirus vaccine contraindication; the infant with encephalopathy matches with the pertussis vaccine contraindication; the child with SCID matches with the live-attenuated vaccine contraindication; and the infant with an egg allergy matches with no contraindication.
Each clinical presentation aligns with a specific immunization rule. Intussusception history strictly contraindicates rotavirus vaccination. Unexplained encephalopathy within 7 days of a DTaP dose strictly contraindicates further pertussis vaccination. Severe cellular immunodeficiency (SCID) strictly contraindicates all live-attenuated vaccines (like MMR and Varicella). Conversely, egg allergy is a false contraindication; the influenza vaccine can and should be administered safely.

Step-by-Step Solution

1
Evaluate the patient with a history of intussusception
Identify that rotavirus vaccine is contraindicated
The rotavirus vaccine specifically increases the risk of intussusception, making prior episodes an absolute contraindication.
2
Evaluate the patient who developed encephalopathy after prior immunizations
Identify that pertussis-containing vaccines (DTaP) are contraindicated
Encephalopathy within 7 days of administration is an absolute contraindication specifically for the pertussis component of the DTaP vaccine.
3
Evaluate the patient with severe combined immunodeficiency (SCID)
Identify that live-attenuated vaccines are contraindicated
Patients with severe cellular immunodeficiency cannot mount a proper immune response and are at high risk of developing severe systemic infections from live vaccine strains.
4
Evaluate the patient with an egg allergy
Identify that there is no contraindication for routine vaccines
Current guidelines state that egg allergy of any severity is not a contraindication to the influenza vaccine (or any other routine childhood vaccine), and it can be safely given in routine settings.

Key Concept

True versus false absolute contraindications for routine childhood immunizations.
Question 535Question →

Match each classic physical examination finding with the most likely rheumatologic diagnosis.

Click a left item, then click its matching right item

Items

Hard, bony outgrowths at the distal interphalangeal (DIP) joints
Violaceous, slightly scaly papules and plaques over the metacarpophalangeal (MCP) joints
Diffuse, uniform swelling of a single digit with accompanying nail pitting
Symmetric MCP joint swelling with ulnar deviation and subluxation

Matches

Show answer & explanation

Answer

Bony DIP outgrowths correspond to osteoarthritis. Violaceous knuckle plaques correspond to dermatomyositis. Diffuse digit swelling with nail pitting corresponds to psoriatic arthritis. Symmetric MCP swelling with ulnar deviation corresponds to rheumatoid arthritis.
Each rheumatologic condition has a classic physical examination signature. Osteoarthritis causes osteophyte formation (Heberden nodes at DIP, Bouchard nodes at PIP). Dermatomyositis presents with pathognomonic skin findings like Gottron papules on the knuckles. Psoriatic arthritis often involves dactylitis (sausage digits) and nail changes due to enthesitis. Rheumatoid arthritis causes erosive, symmetric synovitis leading to ulnar deviation and subluxation at the MCP joints.

Step-by-Step Solution

1
Analyze the specific joint involvement and associated dermatologic findings for each presentation.
Identified distinct patterns pathognomonic for four major rheumatologic diseases.
Pattern recognition of physical exam findings is the primary step in diagnosing and differentiating rheumatologic conditions.

Key Concept

Physical examination hallmarks in rheumatologic diseases
Question 536Question →

A medical student is reviewing common adverse effects of antihypertensive medications frequently prescribed in the primary care setting. Match each patient's clinical presentation to the antihypertensive medication most likely responsible for their symptoms.

Click a left item, then click its matching right item

Items

A 55-year-old woman develops a persistent, dry, hacking cough a few weeks after starting a new medication for hypertension.
A 62-year-old man presents with bilateral, pitting ankle edema that worsens by the end of the day.
A 48-year-old man presents with acute, severe pain, swelling, and erythema in his right first metatarsophalangeal joint.
A 50-year-old man complains of new-onset fatigue, exercise intolerance, and cold extremities.

Matches

Show answer & explanation

Answer

The correct matches align the persistent dry cough with Lisinopril, the pitting ankle edema with Amlodipine, the acute gout flare with Hydrochlorothiazide, and the fatigue with cold extremities with Metoprolol.
Each clinical presentation represents a classic, high-yield adverse effect of a primary antihypertensive drug class. Lisinopril (ACE inhibitor) causes a bradykinin-mediated cough. Amlodipine (calcium channel blocker) causes peripheral edema via precapillary vasodilation. Hydrochlorothiazide (thiazide diuretic) decreases renal uric acid excretion, precipitating gout. Metoprolol (beta-blocker) reduces cardiac output, leading to fatigue and cold extremities.

Step-by-Step Solution

1
Analyze the first presentation (dry cough).
Identified as a bradykinin-mediated adverse effect.
Points to an ACE inhibitor (Lisinopril).
2
Analyze the second presentation (pitting ankle edema).
Identified as a precapillary vasodilation effect.
Points to a dihydropyridine calcium channel blocker (Amlodipine).
3
Analyze the third presentation (acute gout flare).
Identified as a consequence of reduced renal uric acid clearance.
Points to a thiazide diuretic (Hydrochlorothiazide).
4
Analyze the fourth presentation (fatigue and cold extremities).
Identified as a result of reduced cardiac output and peripheral vasoconstriction.
Points to a beta-blocker (Metoprolol).

Key Concept

Adverse effects of first-line antihypertensive medications.
Question 537Question →

Match each classic clinical presentation to the most likely hematologic diagnosis.

Click a left item, then click its matching right item

Items

A 65-year-old man with progressive lower back pain, hypercalcemia, and acute kidney injury.
A 25-year-old woman with painless cervical lymphadenopathy and a widening mediastinum on chest x-ray.
A 60-year-old man with fatigue, early satiety due to massive splenomegaly, and a BCR-ABL1 mutation.
A 70-year-old asymptomatic man found to have marked, isolated absolute lymphocytosis on routine blood work.

Matches

Show answer & explanation

Answer

The patient with back pain and hypercalcemia matches Multiple myeloma. The young woman with a mediastinal mass matches Hodgkin lymphoma. The patient with massive splenomegaly and BCR-ABL1 matches Chronic myeloid leukemia. The asymptomatic elderly man with lymphocytosis matches Chronic lymphocytic leukemia.
Each clinical vignette provides pathognomonic or highly characteristic features for its respective malignancy. Multiple myeloma features CRAB criteria. Hodgkin lymphoma classically affects young adults with cervical and mediastinal adenopathy. Chronic myeloid leukemia is defined by the BCR-ABL1 translocation and often presents with splenomegaly. Chronic lymphocytic leukemia typically presents as an incidental extreme lymphocytosis in older adults.

Step-by-Step Solution

1
Analyze the first presentation (back pain, hypercalcemia, kidney injury).
Identifies the diagnosis as Multiple myeloma.
These symptoms fulfill the CRAB criteria (Calcium, Renal, Anemia, Bone) characteristic of this plasma cell dyscrasia.
2
Analyze the second presentation (young female, painless lymphadenopathy, mediastinal mass).
Identifies the diagnosis as Hodgkin lymphoma.
This matches the classic bimodal age distribution and typical nodal involvement of this lymphoma.
3
Analyze the third presentation (splenomegaly, BCR-ABL1 mutation).
Identifies the diagnosis as Chronic myeloid leukemia.
Early satiety from splenomegaly and the BCR-ABL1 mutation are the hallmark diagnostic features.
4
Analyze the fourth presentation (elderly, asymptomatic lymphocytosis).
Identifies the diagnosis as Chronic lymphocytic leukemia.
This is the most common presentation of CLL, often discovered incidentally on routine laboratory testing.

Key Concept

Classic clinical presentations of major hematologic malignancies
Question 538Question →

Match each clinical presentation of a chemotherapy-induced adverse effect to the specific antineoplastic agent responsible for the toxicity.

Click a left item, then click its matching right item

Items

A 28-year-old man receiving bleomycin, etoposide, and cisplatin for testicular cancer develops a dry cough and progressive dyspnea; pulmonary function tests show a restrictive pattern.
A 48-year-old woman receiving rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone for non-Hodgkin lymphoma presents with suprapubic pain and gross hematuria.
A 62-year-old man receiving bleomycin, etoposide, and cisplatin for advanced testicular cancer complains of persistent bilateral tinnitus and progressive sensorineural hearing loss.
A 55-year-old woman receiving doxorubicin and cyclophosphamide for breast cancer develops new-onset orthopnea, bilateral basilar crackles, and a reduced left ventricular ejection fraction.
A 60-year-old man receiving rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone for diffuse large B-cell lymphoma reports a subacute 'pins and needles' sensation in his distal extremities and absent ankle reflexes.

Matches

Show answer & explanation

Answer

The correct matches align the clinical toxicity to its specific causative agent: Bleomycin causes pulmonary fibrosis; Cyclophosphamide causes hemorrhagic cystitis; Cisplatin causes ototoxicity; Doxorubicin causes dilated cardiomyopathy; and Vincristine causes peripheral neuropathy.
Each clinical scenario describes a classic dose-limiting toxicity that corresponds to exactly one agent in the patient's regimen. Bleomycin causes pulmonary fibrosis; Cyclophosphamide causes hemorrhagic cystitis; Cisplatin causes ototoxicity; Doxorubicin causes dilated cardiomyopathy; and Vincristine causes peripheral neuropathy.

Step-by-Step Solution

1
Analyze the first vignette describing restrictive lung disease in a patient on BEP therapy.
The primary symptom is pulmonary fibrosis.
Identifying the specific organ toxicity allows isolation of the responsible drug from the combination regimen.
2
Match pulmonary fibrosis to its causative agent in the BEP regimen.
Bleomycin is the correct match.
Bleomycin is classically associated with dose-dependent pulmonary toxicity.
3
Analyze the second vignette describing gross hematuria in a patient on R-CHOP therapy.
The presentation represents hemorrhagic cystitis.
This is a classic urologic emergency associated with specific alkylating agents.
4
Match hemorrhagic cystitis to its causative agent.
Cyclophosphamide is the correct match.
Acrolein, a cyclophosphamide metabolite, is highly toxic to the bladder epithelium.
5
Analyze the third vignette describing tinnitus and hearing loss in a patient on BEP therapy.
The symptom is ototoxicity.
Hearing loss is a highly specific neurological toxicity that must be recognized.
6
Match ototoxicity to its causative agent.
Cisplatin is the correct match.
Platinum analogues, especially cisplatin, are heavily ototoxic and nephrotoxic.
7
Analyze the fourth vignette describing heart failure (reduced ejection fraction) in a patient on AC therapy.
The symptom is dilated cardiomyopathy.
Cardiotoxicity is a dose-limiting side effect for certain key oncology drugs.
8
Match dilated cardiomyopathy to its causative agent.
Doxorubicin is the correct match.
Anthracyclines like doxorubicin cause cumulative myocardial free-radical damage.
9
Analyze the fifth vignette describing absent ankle reflexes and paresthesias in a patient on R-CHOP therapy.
The symptom is peripheral neuropathy.
Areflexia and a 'pins and needles' sensation indicate peripheral nerve damage.
10
Match peripheral neuropathy to its causative agent.
Vincristine is the correct match.
Vinca alkaloids disrupt microtubules, uniquely causing peripheral neuropathy rather than the severe myelosuppression seen with other agents.

Key Concept

Major chemotherapeutic agents have distinct, highly tested dose-limiting toxicities that must be recognized when patients on combination regimens present with new symptoms.
Question 539Question →

Match each patient's clinical presentation with the autoantibody or immunologic marker most strongly associated with their underlying disease process.

Click a left item, then click its matching right item

Items

A 48-year-old woman presenting with proximal muscle weakness, hyperkeratotic cracking on the lateral aspects of her fingers, and new-onset interstitial lung disease.
A 32-year-old woman with a history of unprovoked pulmonary embolism presenting with recurrent mid-trimester pregnancy losses and an isolated prolonged PTT.
A 55-year-old man with palpable purpura, arthralgias, peripheral neuropathy, and hypocomplementemia (low C4), who recently tested positive for Hepatitis C.
A 60-year-old woman with severe xerophthalmia, xerostomia, and bilateral parotid gland enlargement who recently noticed a rapidly enlarging cervical lymph node.

Matches

Show answer & explanation

Answer

Antisynthetase syndrome matches with Anti-Jo-1; Antiphospholipid syndrome matches with Anti-beta-2-glycoprotein I; Mixed cryoglobulinemia matches with Rheumatoid factor; Sjögren syndrome matches with Anti-Ro/SSA.
Each left item provides a high-yield, specific clinical vignette for a systemic autoimmune disease. Antisynthetase syndrome is driven by anti-Jo-1; antiphospholipid syndrome relies on markers like anti-beta-2-glycoprotein I; Hepatitis C-associated mixed cryoglobulinemia features IgM rheumatoid factor; and Sjögren syndrome is characterized by anti-Ro/SSA antibodies.

Step-by-Step Solution

1
Analyze the first patient's symptoms (myositis, mechanic's hands, interstitial lung disease) to diagnose antisynthetase syndrome.
Identify Anti-Jo-1 as the highly specific antibody for this condition.
Anti-Jo-1 targets histidyl-tRNA synthetase and defines this distinct subset of inflammatory myopathies.
2
Evaluate the second patient's history of thrombosis, pregnancy loss, and isolated prolonged PTT to diagnose antiphospholipid syndrome.
Identify Anti-beta-2-glycoprotein I as one of the defining diagnostic autoantibodies.
The prolonged PTT is an in vitro artifact of the lupus anticoagulant; the syndrome is mediated by antibodies against phospholipid-binding proteins.
3
Correlate the third patient's palpable purpura, neuropathy, low C4, and Hepatitis C with mixed cryoglobulinemia.
Identify Rheumatoid factor as the key immunologic marker.
Type II mixed cryoglobulins are immune complexes composed of polyclonal IgG and monoclonal IgM; the IgM component possesses rheumatoid factor activity (affinity for the Fc portion of IgG), which consumes complement C4.
4
Recognize the fourth patient's sicca symptoms, parotid swelling, and new lymphadenopathy as Sjögren syndrome with likely lymphomatous transformation.
Identify Anti-Ro/SSA antibodies as the classic serologic marker.
Sjögren syndrome carries a significantly elevated risk for B-cell non-Hodgkin lymphoma, and is diagnosed using Anti-Ro/SSA and Anti-La/SSB antibodies.

Key Concept

Clinical and serologic correlations in systemic autoimmune and rheumatic diseases
Question 540Question →

Match each clinical presentation of pneumonia with the most likely causative pathogen based on classic epidemiological risk factors and clinical findings.

Click a left item, then click its matching right item

Items

A 45-year-old man with severe alcohol use disorder presents with fever, productive cough with thick, blood-tinged sputum, and an upper lobe cavitary lesion.
A 20-year-old college student living in a dormitory presents with persistent dry cough, mild fever, and a chest x-ray showing bilateral interstitial infiltrates.
A 65-year-old man presents with high fever, relative bradycardia, confusion, diarrhea, and hyponatremia shortly after returning from a hotel convention.
A 30-year-old pet shop worker presents with high fever, severe headache, and dry cough after extensive exposure to exotic parrots and macaws.

Matches

Show answer & explanation

Answer

Alcoholism points to Klebsiella pneumoniae; dormitory residence points to Mycoplasma pneumoniae; hotel water exposure with hyponatremia points to Legionella pneumophila; and bird exposure points to Chlamydia psittaci.
Each respiratory pathogen is uniquely associated with specific environmental exposures and host risk factors that help guide empiric diagnostic testing and targeted antimicrobial selection.

Step-by-Step Solution

1
Evaluate the first vignette for host risk factors and sputum characteristics.
Matches Klebsiella pneumoniae.
The patient has a history of alcohol use disorder, which predisposes to aspiration, and presents with classic 'currant jelly' sputum and cavitation.
2
Evaluate the second vignette for patient age and living environment.
Matches Mycoplasma pneumoniae.
The patient is a young adult in a crowded dormitory environment presenting with atypical pneumonia symptoms.
3
Evaluate the third vignette for environmental exposure and extrapulmonary symptoms.
Matches Legionella pneumophila.
The patient has exposure to a hotel (suggesting a contaminated water source) and presents with classic extrapulmonary features including diarrhea, confusion, and hyponatremia.
4
Evaluate the fourth vignette for zoonotic exposure.
Matches Chlamydia psittaci.
The patient has occupational exposure to birds, which is the primary transmission route for psittacosis.

Key Concept

Epidemiological risk factors and classic clinical syndromes of pneumonia pathogens.
Estimated Time:1m 0s
PreviousPage 27 / 93Next
All practice questions — USMLE Step 2 CK | Examkin