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Question 481Question →

A clinic focuses on the evaluation and management of severe and resistant hypertension. Match each patient's clinical presentation with the most appropriate initial diagnostic test for their suspected secondary cause of hypertension.

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Items

A 45-year-old man with persistent hypertension despite maximum tolerated doses of amlodipine, lisinopril, and chlorthalidone. Routine laboratory results reveal a serum potassium level of 2.9 mEq/L.
A 38-year-old woman evaluated for episodic spells of pounding headaches, profuse nonexertional sweating, and tachycardia, accompanied by blood pressure elevations up to 210/110 mm Hg.
A 26-year-old woman presenting with new-onset hypertension of 175/105 mm Hg and a subauricular bruit appreciated on physical examination.
A 48-year-old woman with difficult-to-control hypertension, recent onset of type 2 diabetes mellitus, easy bruising, and an unexplained osteoporotic vertebral compression fracture.

Matches

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Answer

The scenarios match their respective diagnostic tests as follows: The patient with hypokalemia requires an aldosterone-to-renin ratio; the patient with episodic headaches and sweating requires plasma free metanephrines; the young woman with a bruit requires CT angiography; and the patient with metabolic and bone abnormalities requires a dexamethasone suppression test.
Each patient's clinical presentation aligns perfectly with a specific secondary cause of hypertension (primary hyperaldosteronism, pheochromocytoma, fibromuscular dysplasia, and Cushing syndrome, respectively), dictating the targeted initial diagnostic tests provided in the correct pairs.

Step-by-Step Solution

1
Analyze the first clinical vignette for key features of secondary hypertension.
Identified drug-resistant hypertension with spontaneous or diuretic-induced hypokalemia, pointing to primary hyperaldosteronism.
Recognizing the classic presentation of primary hyperaldosteronism dictates the selection of the aldosterone-to-renin ratio as the initial screen.
2
Evaluate the second vignette for episodic symptoms.
Identified the triad of headache, sweating, and tachycardia with hypertensive emergencies, indicating pheochromocytoma.
Pheochromocytoma requires biochemical screening for catecholamine excess using plasma free metanephrines.
3
Assess the third vignette involving a young patient with a specific physical exam finding.
Identified severe hypertension in a young female with a subauricular bruit, highly suggestive of fibromuscular dysplasia.
FMD requires vascular imaging, making CT angiography or duplex ultrasound the appropriate initial diagnostic step.
4
Analyze the fourth vignette for systemic signs of endocrine dysfunction.
Identified hypertension accompanied by diabetes, bruising, and osteoporosis, characterizing Cushing syndrome.
Cushing syndrome requires demonstration of hypercortisolism, best initially screened with a low-dose dexamethasone suppression test.

Key Concept

Identification of distinct secondary causes of hypertension and selection of their appropriate initial screening modalities.
Question 482Question →

Match each clinical presentation with its corresponding primary acid-base disorder.

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Items

A previously healthy patient complains of profuse watery stools for several days. Arterial blood gas reveals a pH of 7.287.28 and PaCO 2_2 of 32 mm Hg32\text{ mm Hg}, while the basic metabolic panel shows an anion gap of 10 mEq/L10\text{ mEq/L}.
During an acute asthma attack, a highly anxious patient presents with a respiratory rate of 32/min32\text{/min}. Laboratory analysis demonstrates a pH of 7.527.52, PaCO 2_2 of 26 mm Hg26\text{ mm Hg}, and a bicarbonate level of 22 mEq/L22\text{ mEq/L}.
Following 4848 hours of relentless emesis due to suspected food poisoning, a patient's laboratory workup indicates a pH of 7.507.50, a PaCO 2_2 of 46 mm Hg46\text{ mm Hg}, and a serum bicarbonate of 34 mEq/L34\text{ mEq/L}.
In a patient admitted to the intensive care unit with profound hypotension and suspected sepsis, blood tests show a pH of 7.227.22, PaCO 2_2 of 30 mm Hg30\text{ mm Hg}, and an anion gap of 24 mEq/L24\text{ mEq/L}.

Matches

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Answer

The clinical scenarios correctly match their respective primary acid-base disturbances based on the primary driver of the pH change: bicarbonate loss in diarrhea (normal gap acidosis), CO2 blow-off in asthma (respiratory alkalosis), acid loss in vomiting (metabolic alkalosis), and lactic acid buildup in sepsis (high gap acidosis).
Each presentation classically alters the acid-base balance through a specific physiologic mechanism. Diarrhea causes direct bicarbonate loss (normal AG metabolic acidosis). Hyperventilation from an acute asthma attack blows off CO2 (respiratory alkalosis). Severe vomiting removes gastric acid and volume (metabolic alkalosis). Poor perfusion from septic shock generates systemic lactate (high AG metabolic acidosis).

Step-by-Step Solution

1
Assess the pH in each scenario to determine if the primary disorder is an acidosis (pH <7.35< 7.35) or an alkalosis (pH >7.45> 7.45).
Identifies the fundamental directional disturbance of the acid-base derangement.
Provides the baseline needed to categorize the primary process before evaluating compensation.
2
Evaluate the PaCO 2_2 and serum bicarbonate levels to identify if the primary etiology is respiratory or metabolic.
Differentiates metabolic conditions (driven by bicarbonate) from respiratory conditions (driven by carbon dioxide).
Determines which physiological system is responsible for the abnormal pH.
3
For patients presenting with metabolic acidosis, evaluate the calculated anion gap using the formula: Na+−(Cl−+HCO3−)Na^+ - (Cl^- + HCO_3^-).
Categorizes the acidosis as either a normal or high anion gap metabolic acidosis.
Narrows down the differential diagnosis significantly, such as distinguishing diarrhea (normal gap) from lactic acidosis (high gap).

Key Concept

Basic interpretation of primary acid-base disorders requires assessing the pH, identifying the primary alteration in PaCO2 or bicarbonate, and calculating the anion gap in all cases of metabolic acidosis.
Question 483Question →

A medical student is reviewing serologic markers for various autoimmune diseases. Match each specific autoantibody below to the rheumatologic condition with which it is most strongly associated.

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Items

Anti-cyclic citrullinated peptide (anti-CCP)
Anti-double-stranded DNA (anti-dsDNA)
Anti-centromere antibody
Anti-Ro/SSA antibody

Matches

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Answer

Anti-CCP matches with Rheumatoid arthritis; Anti-dsDNA matches with Systemic lupus erythematosus (SLE); Anti-centromere matches with Limited cutaneous systemic sclerosis; Anti-Ro/SSA matches with Sjögren syndrome.
Each autoantibody serves as a specific diagnostic marker for a distinct rheumatologic condition. Anti-CCP is specific for rheumatoid arthritis, anti-dsDNA for SLE, anti-centromere for limited cutaneous systemic sclerosis, and anti-Ro/SSA for Sjögren syndrome.

Step-by-Step Solution

1
Identify the disease association for anti-CCP.
Anti-CCP is linked to Rheumatoid arthritis.
It is a highly specific marker for RA that helps differentiate it from other inflammatory arthritides.
2
Identify the disease association for anti-dsDNA.
Anti-dsDNA is linked to Systemic lupus erythematosus (SLE).
It is a specific marker for SLE that often fluctuates with disease flares.
3
Identify the disease association for anti-centromere.
Anti-centromere is linked to Limited cutaneous systemic sclerosis.
It is the primary autoantibody found in patients with the limited form of systemic sclerosis.
4
Identify the disease association for anti-Ro/SSA.
Anti-Ro/SSA is linked to Sjögren syndrome.
It is frequently tested during the diagnostic workup for sicca symptoms characteristic of Sjögren syndrome.

Key Concept

Autoantibody profiles are essential in the diagnosis and classification of rheumatologic diseases.
Question 484Question →

Match the following classic dermatological findings with the infectious disease they most accurately represent.

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Items

An expanding, erythematous, annular plaque with central clearing (targetoid appearance).
A blanching, maculopapular rash that classically originates on the wrists and ankles before spreading centrally to the trunk.
A painful, vesicular eruption distributed unilaterally along a single thoracic dermatome.
A confluent, erythematous, 'slapped cheek' facial appearance followed by a lacy, reticular rash on the extremities and trunk.

Matches

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Answer

The correct matches are: Erythema migrans with Lyme disease, centripetal maculopapular rash with Rocky Mountain spotted fever, dermatomal vesicular rash with Herpes zoster, and the 'slapped cheek' appearance with Erythema infectiosum.
Each of these dermatological findings is a classic, highly specific manifestation of its respective infectious disease. Recognizing these visual patterns allows clinicians to promptly initiate targeted therapy (e.g., doxycycline for Lyme disease or Rocky Mountain spotted fever) often before confirmatory laboratory results are available.

Step-by-Step Solution

1
Analyze the targetoid (bull's-eye) rash description.
Identified as erythema migrans, matching Lyme disease.
Erythema migrans is the hallmark clinical sign of early Lyme disease, allowing for a clinical diagnosis without initial serologic testing.
2
Analyze the rash starting on the wrists and ankles and spreading centrally.
Identified as the classic rash pattern for Rocky Mountain spotted fever.
This distinct centripetal pattern (extremities to trunk) is a key diagnostic clue for Rickettsia rickettsii infection.
3
Analyze the unilateral, painful, vesicular rash in a single dermatome.
Identified as shingles, matching Herpes zoster.
Varicella-zoster virus remains latent in nerve ganglia and its reactivation strictly follows dermatomal lines, not crossing the midline.
4
Analyze the 'slapped cheek' rash followed by a reticular pattern.
Identified as Fifth disease, matching Erythema infectiosum.
This biphasic rash pattern in a child is pathognomonic for Parvovirus B19 infection.

Key Concept

Recognition of classic dermatological manifestations of infectious diseases.
Estimated Time:45s
Question 485Question →

A healthy 18-month-old child is evaluated at the pediatric clinic for a routine well-child visit. The physician performs a comprehensive developmental assessment to ensure the child is acquiring skills at the expected rate. Which specific skill is expected to be achieved by this age in each of the following developmental domains? Match each developmental domain with its appropriate 18-month milestone.

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Items

Gross Motor Development
Fine Motor Development
Language Development
Social and Adaptive Development

Matches

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Answer

The correct matching aligns Gross Motor with 'Runs stiffly and walks up stairs while holding a hand', Fine Motor with 'Builds a tower of 3 to 4 cubes', Language with 'Uses 10 to 25 single words and points to one body part', and Social and Adaptive with 'Feeds self with a spoon and points to objects to share interest'.
An 18-month-old child typically demonstrates specific milestones across four primary domains. Gross motor development involves large muscle groups, allowing the child to run stiffly and climb stairs with support. Fine motor development requires hand-eye coordination, enabling the stacking of 3 to 4 cubes. Language development includes both expressive (10-25 words) and receptive (pointing to one body part) components. Social and adaptive development is highlighted by increasing independence, such as feeding oneself with a spoon, and engaging in joint attention by pointing to share interest. Categorizing these properly confirms an understanding of standard pediatric milestone acquisition.

Step-by-Step Solution

1
Identify the chronological age of the child in the clinical scenario.
The child is 18 months old.
Developmental milestones are evaluated based on the child's exact chronological age.
2
Recall the standard developmental milestones expected for an 18-month-old across all four major domains.
Gross motor includes running; fine motor includes a 3-4 cube tower; language includes 10-25 words; social includes using a spoon and displaying joint attention.
This establishes the clinical benchmark needed to categorize the given skills accurately.
3
Match each presented skill to its corresponding developmental domain.
Physical locomotion matches gross motor; block stacking matches fine motor; speech matches language; self-feeding matches social/adaptive.
To complete the diagnostic matching exercise correctly based on physiological and cognitive development.

Key Concept

Normal 18-month developmental milestones across gross motor, fine motor, language, and social domains.
Question 486Question →

Match each clinical presentation with its most characteristic peripheral blood smear finding.

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Items

Routine preoperative laboratory testing for an asymptomatic 65-year-old man reveals a white blood cell count of 55,000/μL55,000/\mu L with marked lymphocytosis.
During evaluation for progressive fatigue and gingival bleeding, a 40-year-old woman is found to have pancytopenia with a high fraction of circulating blasts.
Two days after initiating trimethoprim-sulfamethoxazole therapy, a 25-year-old man develops acute jaundice, dark urine, and a rapidly falling hemoglobin level.
A rapid response is called for a 35-year-old woman who develops sudden-onset confusion, fever, acute kidney injury, and profound thrombocytopenia.

Matches

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Answer

The asymptomatic older male with marked lymphocytosis matches with fragile leukocyte remnants (smudge cells). The patient with pancytopenia and circulating blasts matches with linear azurophilic granules (Auer rods). The young man with sulfa-induced hemolysis matches with semicircular erythrocyte defects (bite cells). The woman with confusion, fever, acute kidney injury, and thrombocytopenia matches with mechanically sheared erythrocytes (schistocytes).
Peripheral blood smear evaluation is critical for distinguishing hematologic pathologies. Smudge cells indicate the fragile monoclonal B-cells of CLL. Auer rods are pathognomonic for myeloblasts in AML. Bite cells indicate splenic phagocytosis of oxidized hemoglobin seen in G6PD deficiency. Schistocytes represent the mechanical destruction of erythrocytes characteristic of microangiopathic hemolytic anemias like TTP.

Step-by-Step Solution

1
Evaluate the first vignette describing an asymptomatic elderly patient with significant incidental lymphocytosis.
Diagnose Chronic Lymphocytic Leukemia (CLL), which pairs with smudge cells due to the characteristic fragility of the malignant lymphocytes.
Identifying the classic demographic and lab presentation of CLL isolates its specific morphologic marker.
2
Analyze the second vignette featuring pancytopenia and circulating blasts in a middle-aged adult.
Diagnose Acute Myeloid Leukemia (AML), which pairs with Auer rods.
Auer rods are pathognomonic for myeloblasts in AML and help distinguish it from acute lymphoblastic leukemia (ALL).
3
Assess the third vignette involving acute hemolysis triggered by a sulfa antibiotic.
Diagnose Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency, which pairs with bite cells (degmacytes).
Sulfa drugs induce oxidative stress in G6PD deficiency, causing Heinz body formation; splenic removal of these bodies produces bite cells.
4
Examine the final vignette showing the classic pentad of fever, neurologic changes, renal failure, and thrombocytopenia.
Diagnose Thrombotic Thrombocytopenic Purpura (TTP), which pairs with schistocytes.
TTP is a microangiopathic hemolytic anemia (MAHA) where microthrombi shear red blood cells as they pass through small vessels.

Key Concept

Recognizing the pathognomonic peripheral blood smear findings associated with highly tested hematologic and oncologic disorders.
Question 487Question →

Match each pediatric patient's clinical presentation with the most appropriate next step in management.

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Items

A 10-month-old infant cannot sit unsupported. A startle response is triggered upon sudden posterior head drop. The infant consistently grasps toys exclusively with the left hand, keeping the right hand fisted.
A 16-month-old toddler cruises along furniture and stands alone briefly, but has not taken independent steps. He uses a neat pincer grasp, speaks five recognizable words, and points to share interest.
A 30-month-old toddler frequently trips and uses his hands to push against his thighs when rising from the floor. He builds an 8-block tower and speaks in three-word sentences.
A 24-month-old toddler engages in complex pretend play, kicks a ball, and follows single-step commands that include a gesture. He uses only four distinct single words and no phrases.

Matches

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Answer

The correct matches pair the 10-month-old with persistent Moro and early handedness to neuroimaging; the 16-month-old late walker to anticipatory guidance; the 30-month-old with Gowers sign to muscle enzyme analysis; and the 24-month-old with isolated language delay to hearing assessment.
Each presentation requires interpreting a constellation of milestones to determine if a delay is an expected normal variant or a pathological red flag requiring a targeted workup. Early handedness indicates focal neurologic injury requiring neuroimaging; late walking up to 18 months without other delays is normal; Gowers sign indicates proximal myopathy requiring muscle enzymes; and isolated language delay necessitates ruling out hearing loss.

Step-by-Step Solution

1
Analyze the 10-month-old's findings (persistent Moro reflex, early handedness, poor trunk control).
Identified as red flags for focal neurologic deficit (spastic hemiplegic cerebral palsy).
Early handedness before 18 months is always abnormal and indicates contralateral weakness, requiring an MRI.
2
Evaluate the 16-month-old's motor delay against normal limits.
Identified as a normal variation because independent walking can normally be achieved up to 18 months.
Since fine motor, language, and social domains are appropriately developed, anticipatory guidance is the correct step.
3
Assess the 30-month-old's method of standing and frequent tripping.
Recognized Gowers sign, indicating proximal muscle weakness.
This is a classic presentation of Duchenne muscular dystrophy, which is initially screened using a serum creatine kinase level.
4
Determine the workup for the 24-month-old with 4 words and normal play.
Identified isolated expressive language delay.
Any child with speech or language delay must undergo formal audiometry as the first step to rule out hearing impairment.

Key Concept

Differentiating normal developmental variation from red flags requiring specific diagnostic workup (e.g., MRI for early handedness, audiometry for isolated speech delay, CK for Gowers sign).
Question 488Question →

Match each clinical presentation of an immunocompromised patient with the most appropriate targeted pharmacotherapy.

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Items

A 32-year-old patient with untreated HIV presents with new-onset seizures; brain MRI reveals multiple ring-enhancing lesions in the basal ganglia.
A 45-year-old patient with untreated HIV presents with subacute headache, fever, and a positive serum cryptococcal antigen test.
A 28-year-old patient with untreated HIV presents with floaters, blurred vision, and yellow-white retinal lesions with associated hemorrhage on funduscopy.
A 39-year-old patient with untreated HIV presents with progressive dyspnea, nonproductive cough, and severe resting hypoxemia (PaO2 60 mmHg); chest imaging shows bilateral ground-glass opacities.

Matches

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Answer

The correct pairings match Toxoplasmosis with pyrimethamine/sulfadiazine/leucovorin, Cryptococcal meningitis with amphotericin B/flucytosine, CMV retinitis with valganciclovir, and severe Pneumocystis pneumonia with TMP-SMX/corticosteroids.
Each targeted pharmacotherapy directly addresses the specific pathogen responsible for the classic opportunistic infection presentations in patients with advanced HIV, adhering to standard induction and primary treatment guidelines.

Step-by-Step Solution

1
Evaluate the clinical and radiographic presentation in each patient to identify the most likely opportunistic infection.
The pathogens are identified as Toxoplasma gondii, Cryptococcus neoformans, Cytomegalovirus (CMV), and Pneumocystis jirovecii.
Accurate diagnosis of the specific opportunistic infection is required before selecting targeted antimicrobial therapy.
2
Select the appropriate primary treatment regimen for each identified pathogen based on current clinical guidelines.
Toxoplasmosis requires pyrimethamine-based therapy; Cryptococcus requires amphotericin-based induction; CMV requires a -ganciclovir derivative; PCP requires TMP-SMX.
Different classes of pathogens (protozoan, fungal, viral) require highly specific antimicrobial mechanisms of action.
3
Assess disease severity for the PCP case to determine if adjunctive therapy is needed.
The patient's PaO2 is 60 mmHg (less than 70 mmHg), indicating severe disease that requires adjunctive corticosteroids.
Steroids prevent the severe inflammatory response that occurs when dying Pneumocystis organisms release inflammatory antigens in the lungs.

Key Concept

Pharmacotherapy for HIV-associated opportunistic infections
Question 489Question →

Match each classic physical examination or imaging finding to its most likely rheumatologic diagnosis.

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Items

Heliotrope rash and Gottron papules
Malar rash sparing the nasolabial folds
Acute, exquisitely tender swelling of the first metatarsophalangeal joint
Progressive lower back pain with morning stiffness and sacroiliitis on imaging

Matches

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Answer

Heliotrope rash/Gottron papules matches with Dermatomyositis; Malar rash matches with Systemic lupus erythematosus; Acute first MTP swelling (podagra) matches with Gout; Sacroiliitis matches with Ankylosing spondylitis.
Each provided clinical vignette highlights the most iconic and highly tested physical examination or imaging finding for its respective rheumatologic condition, requiring direct pattern recognition.

Step-by-Step Solution

1
Evaluate the cutaneous findings of a heliotrope rash and Gottron papules.
Identified as dermatomyositis.
These are highly specific pathognomonic skin signs of this inflammatory myopathy.
2
Evaluate the malar rash that spares the nasolabial folds.
Identified as systemic lupus erythematosus.
Sparing of the nasolabial folds distinguishes the SLE malar rash from conditions like rosacea or seborrheic dermatitis.
3
Evaluate the acute swelling of the first metatarsophalangeal joint.
Identified as gout.
This specific joint involvement is called podagra, characteristic of monosodium urate crystal deposition.
4
Evaluate the progressive lower back pain with sacroiliitis.
Identified as ankylosing spondylitis.
This is a seronegative spondyloarthropathy characterized by inflammation of the axial skeleton, particularly the sacroiliac joints.

Key Concept

Classic clinical presentations in rheumatology
Question 490Question →

Match each diagnostic hematologic profile with its corresponding primary molecular pathogenesis and targeted therapeutic approach.

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Items

Bone marrow aspirate shows hypercellularity with >20% blasts containing abundant cytoplasm, multiple Auer rods, and strong myeloperoxidase positivity; cytogenetics reveal a t(15;17) translocation.
Peripheral blood flow cytometry demonstrates a clonal B-cell population expressing CD19, CD20, CD11c, CD25, CD103, and CD123, with marked monocytopenia.
Lymph node biopsy reveals an effaced architecture with a monotonous proliferation of small-to-medium lymphocytes; FISH is positive for t(11;14)(q13;q32).
Bone marrow evaluation of a patient with massive splenomegaly shows marked fibrosis and megakaryocytic atypia; molecular testing reveals a gain-of-function mutation in the JAK2 gene (V617F).
Bone marrow biopsy reveals >10% clonal plasma cells, and flow cytometry shows CD38+ and CD138+ cells; peripheral blood shows rouleaux formation.

Matches

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Answer

Acute promyelocytic leukemia matches with retinoic acid receptor disruption. Hairy cell leukemia matches with the BRAF V600E mutation. Mantle cell lymphoma matches with Cyclin D1 overexpression. Primary myelofibrosis matches with constitutive non-receptor tyrosine kinase activation. Multiple myeloma matches with monoclonal immunoglobulin overproduction.
Each diagnostic profile presents hallmark cytogenetic, immunophenotypic, or morphological features of a specific hematologic malignancy. Accurate matching requires linking these diagnostic features to their direct pathophysiological consequences and standard-of-care treatments.

Step-by-Step Solution

1
Analyze the diagnostic profile for the first item.
Identifies acute promyelocytic leukemia (APL) based on greater than 20% blasts, multiple Auer rods, and the t(15;17) translocation.
Recognizing the unique cytogenetic and morphological signature of APL is required to determine the specific molecular mechanism.
2
Match APL with its pathogenesis and targeted treatment.
Links APL to the disruption of retinoic acid receptor signaling and treatment with a vitamin A derivative (ATRA) and arsenic trioxide.
The PML-RARA fusion protein creates a maturation block that specific targeted therapies can overcome.
3
Evaluate the immunophenotype of the second item.
Identifies hairy cell leukemia from the specific CD markers (CD11c, CD25, CD103) and marked monocytopenia.
This distinct flow cytometry profile differentiates it from other indolent B-cell neoplasms.
4
Connect hairy cell leukemia to its genetic driver and therapy.
Links to the BRAF V600E mutation and purine analog therapy, such as cladribine.
The BRAF mutation is nearly universal in this disease and dictates targeted therapeutic approaches.
5
Assess the cytogenetics of the third item.
Identifies mantle cell lymphoma based on t(11;14) and the proliferation of small-to-medium lymphocytes.
The translocation uniquely identifies this lymphoma subtype among other small B-cell lymphomas.
6
Associate mantle cell lymphoma with its molecular consequence.
Links t(11;14) to Cyclin D1 overexpression and potential treatment with Bruton tyrosine kinase (BTK) inhibitors.
Cyclin D1 drives the G1-to-S phase transition, characteristic of this aggressive lymphoma.
7
Analyze the bone marrow findings of the fourth item.
Identifies primary myelofibrosis due to massive splenomegaly, marked fibrosis, megakaryocytic atypia, and the JAK2 mutation.
Clinical and molecular features precisely define this myeloproliferative neoplasm.
8
Connect primary myelofibrosis to its pathophysiology and symptomatic treatment.
Links to constitutive activation of a non-receptor tyrosine kinase (JAK2) and ruxolitinib therapy.
Targeted JAK inhibition effectively controls massive splenomegaly and constitutional symptoms.
9
Evaluate the diagnostic findings in the fifth item.
Identifies multiple myeloma based on greater than 10% clonal plasma cells, CD38/CD138 positivity, and rouleaux formation.
These are the classic diagnostic criteria for this plasma cell dyscrasia.
10
Match multiple myeloma to its disease mechanisms and core therapy.
Links to monoclonal protein overproduction causing end-organ damage and treatment with proteasome inhibitors.
Proteasome inhibitors are uniquely effective due to the heavy protein synthesis burden in malignant plasma cells.

Key Concept

Molecular pathogenesis, diagnostic criteria, and targeted therapies for specific hematologic malignancies.
Question 491Question →

A general internist is conducting preoperative evaluations for several patients scheduled for elective surgeries next week. Match each patient's chronic medication scenario to the most appropriate perioperative management recommendation.

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Items

Lisinopril for essential hypertension in a patient undergoing an elective laparoscopic cholecystectomy.
Warfarin for atrial fibrillation (CHA2DS2-VASc score = 1) in a patient scheduled for an elective total hip arthroplasty.
Empagliflozin for type 2 diabetes mellitus in a patient undergoing an elective open bowel resection.
Sublingual buprenorphine-naloxone for opioid use disorder in a patient scheduled for an elective lumbar spinal fusion.
Raloxifene for osteoporosis in a patient undergoing an elective total knee arthroplasty.

Matches

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Answer

Lisinopril is withheld the morning of surgery; Warfarin is stopped 5 days prior without bridging; Empagliflozin is stopped 3-4 days prior; Buprenorphine is continued throughout; and Raloxifene is stopped 4 weeks prior.
Correct matching requires identifying the specific physiological risks posed by each medication during surgery and anesthesia. ACE inhibitors risk severe vasoplegia; SGLT2 inhibitors risk euglycemic DKA; SERMs risk VTE. Conversely, stopping buprenorphine risks severe withdrawal, and low-risk warfarin patients do not require bridging.

Step-by-Step Solution

1
Analyze the ACE inhibitor scenario.
Lisinopril matches with withholding on the morning of surgery.
Prevents refractory hypotension during anesthesia induction.
2
Analyze the Warfarin scenario.
Warfarin matches with stopping 5 days prior without bridging.
Low thromboembolic risk (CHA2DS2-VASc = 1) does not warrant bridging, but INR must normalize.
3
Analyze the SGLT2 inhibitor scenario.
Empagliflozin matches with stopping 3-4 days prior.
Mitigates the risk of perioperative euglycemic diabetic ketoacidosis.
4
Analyze the Buprenorphine scenario.
Buprenorphine matches with continuing the current maintenance dose.
Prevents opioid withdrawal and maintains baseline tolerance for multimodal pain management.
5
Analyze the SERM scenario.
Raloxifene matches with stopping 4 weeks prior.
Reduces the elevated risk of venous thromboembolism associated with major orthopedic surgery.

Key Concept

Perioperative medication management requires balancing the risks of disease exacerbation upon discontinuation against the physiological stresses and drug interactions associated with anesthesia and surgery.
Question 492Question →

Match each clinical presentation to its most likely cause of secondary hypertension.

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Items

Episodic palpitations, diaphoresis, and severe headache
Resistant hypertension associated with spontaneous hypokalemia
Severe, new-onset hypertension with an abdominal bruit
Resistant hypertension, obesity, loud snoring, and daytime somnolence

Matches

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Answer

The correct matches pair episodic sympathetic symptoms with pheochromocytoma, hypokalemia with primary hyperaldosteronism, abdominal bruits with renal artery stenosis, and snoring with obstructive sleep apnea.
Secondary causes of hypertension present with distinct clinical clues that help differentiate them from primary (essential) hypertension. Pheochromocytoma is characterized by paroxysmal sympathetic hyperactivity. Primary hyperaldosteronism leads to aldosterone-mediated hypokalemia. Renal artery stenosis typically presents with signs of renovascular disease, notably an abdominal bruit. Obstructive sleep apnea is strongly associated with mechanical airway obstruction signs, such as snoring and excessive daytime somnolence.

Step-by-Step Solution

1
Analyze the first presentation ('Episodic palpitations, diaphoresis, and severe headache').
This classic triad suggests episodic surges in catecholamines.
Pheochromocytoma is a catecholamine-secreting adrenal tumor.
2
Analyze the second presentation ('Resistant hypertension associated with spontaneous hypokalemia').
Hypokalemia in the setting of hypertension suggests an excess of mineralocorticoids.
Primary hyperaldosteronism leads to increased sodium reabsorption and potassium excretion.
3
Analyze the third presentation ('Severe, new-onset hypertension with an abdominal bruit').
An abdominal bruit indicates turbulent blood flow in the renal arteries.
Renal artery stenosis restricts renal blood flow, persistently activating the renin-angiotensin-aldosterone system.
4
Analyze the fourth presentation ('Resistant hypertension, obesity, loud snoring, and daytime somnolence').
These are the hallmark signs of sleep-disordered breathing.
Obstructive sleep apnea causes intermittent hypoxemia and increased sympathetic tone, leading to elevated blood pressure.

Key Concept

Clinical presentations of secondary hypertension
Question 493Question →

Match each clinical vignette describing an adverse pharmacologic event to the most accurate underlying pharmacokinetic or pharmacodynamic mechanism of drug interaction.

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Items

A 71-year-old man with a mechanical mitral valve on chronic anticoagulation develops gross hematuria and an INR of 7.2 three days after starting empiric oral therapy for an uncomplicated urinary tract infection.
A 52-year-old woman with stable bipolar disorder and essential hypertension presents with new-onset ataxia, coarse tremors, and confusion three weeks after a first-line diuretic is added for blood pressure control.
A 77-year-old man taking a lipid-lowering agent for coronary artery disease develops profound muscle weakness and an acute rise in serum creatinine after being treated for a severe chronic obstructive pulmonary disease exacerbation.
A 49-year-old man taking an immunosuppressant for severe Crohn's disease develops acute, severe pancytopenia one month after starting a new daily medication to prevent recurrent attacks of podagra.

Matches

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Answer

The correct matches require identifying the specific drug-drug interaction mechanisms: TMP-SMX inhibits CYP2C9 (elevating warfarin), thiazides increase proximal reabsorption of sodium and lithium, clarithromycin inhibits CYP3A4 (elevating statins), and allopurinol inhibits xanthine oxidase (preventing azathioprine/6-MP degradation).
Each clinical scenario requires a two-step deduction: first, identifying the unstated offending drug, and second, identifying the specific pharmacokinetic mechanism. Warfarin is metabolized by CYP2C9, which is inhibited by TMP-SMX. Lithium is reabsorbed in the proximal tubule alongside sodium, a process enhanced when thiazides cause downstream volume depletion. Statins are metabolized by CYP3A4, which is potently inhibited by macrolides like clarithromycin. Azathioprine is converted to 6-mercaptopurine, which requires xanthine oxidase for degradation; allopurinol inhibits this enzyme, causing toxic accumulation and pancytopenia.

Step-by-Step Solution

1
Analyze the vignette of the patient with the mechanical valve and UTI.
The patient is on warfarin and was likely given trimethoprim-sulfamethoxazole (TMP-SMX) for the UTI.
Identifying the baseline high-risk drug and the likely new empiric antibiotic is required to deduce the mechanism.
2
Analyze the vignette of the bipolar patient with new hypertension.
The patient is on lithium and was likely given a thiazide diuretic.
Thiazides are common first-line antihypertensives that have a classic, severe interaction with renal lithium handling.
3
Analyze the vignette of the COPD patient on a lipid-lowering agent.
The patient is on a statin and was likely treated with a macrolide (e.g., clarithromycin) for the COPD exacerbation.
Macrolides are frequently used for respiratory tract infections and are notorious inhibitors of hepatic enzymes.
4
Analyze the vignette of the Crohn's disease patient with gout.
The patient is on azathioprine (or 6-mercaptopurine) and was started on allopurinol for gout prevention.
Gout prevention involves urate-lowering therapy, which can catastrophically interfere with purine analog metabolism.

Key Concept

Polypharmacy drug interactions in internal medicine often involve highly specific alterations in cytochrome P450 metabolism, renal tubular handling, or shared enzymatic degradation pathways.
Question 494Question →

During well-child visits, developmental surveillance is critical for early identification of delays. Various gross motor, fine motor, and adaptive milestones predictably emerge at specific ages. Match each set of developmental milestones to the most appropriate chronological age of the child.

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Items

Pulls to stand, uses an immature (3-finger) pincer grasp, and plays peek-a-boo
Walks well independently, scribbles spontaneously, and drinks from a cup
Runs, builds a tower of 4 cubes, and removes own clothing
Hops on one foot, copies a square, and engages in cooperative play

Matches

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Answer

The milestones match as follows: Pulls to stand/immature pincer is 9 months. Walks well/scribbles is 15 months. Runs/4-cube tower is 18 months. Hops on one foot/copies square is 48 months (4 years).
Each chronological age corresponds to predictable milestones. 9 months: pulling to stand and immature pincer grasp. 15 months: walking well and scribbling. 18 months: running and 4-cube tower. 48 months: hopping on one foot and copying a square.

Step-by-Step Solution

1
Analyze the first set of milestones: pulls to stand, immature pincer grasp, plays peek-a-boo.
These align with the 9-month developmental age.
Before walking (12 months), infants pull to stand (9 months). The pincer grasp is immature (using three fingers) before refining into a mature two-finger grasp at 12 months.
2
Analyze the second set of milestones: walks well independently, scribbles, drinks from a cup.
These align with the 15-month developmental age.
By 15 months, the unsteady walking of a 12-month-old becomes confident walking. Fine motor control advances to allow holding a cup and scribbling spontaneously.
3
Analyze the third set of milestones: runs, builds a 4-cube tower, removes clothing.
These align with the 18-month developmental age.
At a year and a half, gross motor skills progress to running, and adaptive skills progress to basic independence such as removing own clothing.
4
Analyze the fourth set of milestones: hops on one foot, copies a square, cooperative play.
These align with the 48-month (4-year) developmental age.
Shape copying follows a predictable sequence: line (2 years), circle (3 years), square (4 years), triangle (5 years). Cooperative play and hopping are also distinct 4-year milestones.

Key Concept

Normal pediatric growth and development requires recognizing expected milestones across gross motor, fine motor, and adaptive/social domains at standardized ages.
Question 495Question →

Review the brief patient descriptions below. Match each clinical scenario with its most likely hematologic diagnosis.

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Items

A 65-year-old man presents with painless cervical lymphadenopathy. Peripheral smear shows numerous small, mature-appearing lymphocytes and several fragmented cells (smudge cells).
A 28-year-old woman develops sudden, severe bleeding from her gums and venipuncture sites. Bone marrow biopsy reveals immature myeloid cells containing numerous needle-like eosinophilic cytoplasmic inclusions.
A 22-year-old man presents with a painless supraclavicular lymph node that becomes painful shortly after drinking alcohol. Lymph node biopsy demonstrates large, binucleated cells with prominent nucleoli.
A 19-year-old man develops jaundice and dark urine two days after starting treatment with sulfamethoxazole-trimethoprim. Peripheral smear reveals cells with semicircular peripheral defects.

Matches

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Answer

The correct pairings connect highly specific pathognomonic clinical presentations and microscopic findings with their respective hematologic disorders.
Each clinical scenario contains classic, pathognomonic findings that correspond directly to a specific hematologic disorder. Recognizing these specific associations is key to arriving at the correct diagnosis for each patient presentation.

Step-by-Step Solution

1
Identify the key demographic and microscopic findings in the first scenario (older male, smudge cells).
Smudge cells are highly characteristic of fragile lymphocytes seen in chronic lymphocytic leukemia.
Matching classic peripheral smear findings allows for rapid diagnosis of hematologic malignancies.
2
Analyze the acute bleeding presentation and needle-like inclusions in the second scenario.
The inclusions are Auer rods, and in the setting of severe acute bleeding, this indicates acute promyelocytic leukemia.
Auer rods are specific to myeloid blasts and APL commonly presents with disseminated intravascular coagulation.
3
Recognize the alcohol-induced nodal pain and binucleated cells in the third scenario.
Alcohol-induced lymph node pain and Reed-Sternberg cells are classic for Hodgkin lymphoma.
These are highly specific hallmark features used to diagnose this particular lymphoma.
4
Evaluate the oxidative drug exposure and bite cells in the fourth scenario.
Oxidative stress causing hemolysis and bite cells points to G6PD deficiency.
Sulfa drugs trigger oxidative damage to hemoglobin, which precipitates as Heinz bodies that are subsequently 'bitten' out by splenic macrophages.

Key Concept

Diagnosis of classic hematologic and oncologic disorders relies heavily on recognizing pathognomonic microscopic findings and specific clinical triggers.
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Question 496Question →

Match each sexually transmitted pathogen with its characteristic primary clinical presentation.

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Items

Treponema pallidum
Haemophilus ducreyi
Klebsiella granulomatis
Chlamydia trachomatis (serovars L1-L3)

Matches

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Answer

Treponema pallidum pairs with the painless indurated ulcer; Haemophilus ducreyi with the painful purulent ulcer; Klebsiella granulomatis with the painless beefy-red ulcer without lymphadenopathy; and Chlamydia trachomatis L1-L3 with the transient ulcer followed by fluctuant buboes.
Genital ulcer diseases are classic presentations that must be differentiated clinically. Treponema pallidum causes primary syphilis, noted for a painless chancre with a clean base. Haemophilus ducreyi causes chancroid, which produces a painful, purulent ulcer with tender nodes. Klebsiella granulomatis causes donovanosis, resulting in a painless, beefy-red, highly vascular ulcer without associated lymphadenopathy. Finally, Chlamydia trachomatis L1-L3 causes lymphogranuloma venereum, starting as a painless transient ulcer and eventually causing painful buboes.

Step-by-Step Solution

1
Identify the presence or absence of pain for each ulcer description.
Painful ulcers suggest Haemophilus ducreyi. Painless ulcers suggest Treponema, Klebsiella, or Chlamydia.
Pain is the primary differentiating clinical feature for the initial evaluation of genital ulcers.
2
Differentiate the painless ulcers based on lymphadenopathy and ulcer appearance.
Indurated with non-tender nodes is Treponema. Beefy-red without nodes is Klebsiella. Transient ulcer with severe fluctuant buboes is Chlamydia L1-L3.
Associated features like lymph node characteristics and the macroscopic appearance of the ulcer base definitively isolate the specific pathogen.

Key Concept

Differentiating genital ulcer diseases by pain profile, ulcer characteristics, and lymphadenopathy.
Question 497Question →

Match each clinical presentation of a vector-borne or zoonotic illness with its most appropriate first-line antimicrobial regimen.

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Items

A 28-year-old pregnant woman (18 weeks gestation) presents with fever, myalgias, and a petechial rash spreading from her wrists and ankles to her trunk following a camping trip in North Carolina.
A 35-year-old asplenic man presents with high fever, jaundice, and severe hemolytic anemia after hiking in Massachusetts. Peripheral blood smear reveals intraerythrocytic tetrad forms.
A 42-year-old man presents with new-onset third-degree atrioventricular block and bilateral facial nerve palsies one month after an expanding annular rash.
A 55-year-old abattoir worker is evaluated for culture-negative endocarditis. Serology reveals a Coxiella burnetii phase I IgG titer of 1:1024.
A 38-year-old landscaper in Missouri presents with an ulcerated cutaneous lesion on his right hand and painful, fluctuant right axillary lymphadenopathy.

Matches

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Answer

The correct matches require identifying nuanced therapeutic indications for severe zoonotic and tick-borne infections: RMSF in pregnancy necessitates doxycycline monotherapy; severe babesiosis in an asplenic patient requires IV clindamycin plus oral quinine; Lyme disease with third-degree heart block requires IV ceftriaxone; chronic Q fever endocarditis requires doxycycline plus hydroxychloroquine; and ulceroglandular tularemia is best treated with IV gentamicin.
The correct pairings rely on synthesizing the infectious diagnosis with specific therapeutic guidelines. For Rocky Mountain Spotted Fever, doxycycline is mandatory despite pregnancy due to its life-saving efficacy. For severe babesiosis in an asplenic patient, standard mild-disease therapy (atovaquone/azithromycin) is insufficient, and clindamycin/quinine is required. Severe Lyme disease with third-degree heart block necessitates IV ceftriaxone to prevent fatal arrhythmias. Chronic Q fever endocarditis requires adding hydroxychloroquine to doxycycline to ensure bactericidal activity within acidic phagolysosomes. Finally, ulceroglandular tularemia is classically treated with parenteral aminoglycosides like gentamicin.

Step-by-Step Solution

1
Diagnose the pathogen based on the epidemiological risk factors and clinical hallmarks.
L1 is RMSF; L2 is Babesiosis; L3 is Lyme Carditis; L4 is Q fever endocarditis; L5 is Tularemia.
Identifying the exact infectious etiology is required before considering targeted antimicrobial therapy.
2
Assess the clinical severity and patient-specific risk factors for each presentation.
Key factors include pregnancy (L1), asplenia with severe hemolysis (L2), complete heart block (L3), chronic endovascular infection (L4), and systemic symptoms with buboes (L5).
Many tick-borne diseases are treated with oral doxycycline in mild cases, but severe presentations or special populations require distinct regimens.
3
Determine the first-line targeted therapy considering the modifying factors.
RMSF overrides pregnancy contraindications for doxycycline; severe babesiosis steps up to clindamycin/quinine; Lyme carditis requires IV cephalosporins; chronic Q fever requires the addition of hydroxychloroquine; and severe tularemia requires aminoglycosides.
Applying specific antibiotic stewardship and clinical guidelines prevents significant morbidity and mortality in these nuanced scenarios.

Key Concept

Management of severe, complicated, or special-population presentations of tick-borne and zoonotic infections.
Question 498Question →

Evaluate the following distinct clinical vignettes detailing patients with specific environmental or occupational exposures. Match each patient's presentation with the most likely causative zoonotic pathogen.

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Items

A 45-year-old meatpacker presents with a 4-week history of undulating fevers, profuse night sweats, and joint pain. Examination reveals hepatosplenomegaly and diffuse lymphadenopathy.
A 32-year-old farmer presents with sudden-onset high fever, retro-orbital headache, and a dry cough two weeks after assisting with lambing. Laboratory tests show elevated transaminases, but standard blood cultures are negative.
A 28-year-old adventure racer presents with high fever, severe calf myalgias, and conjunctival suffusion one week after participating in an obstacle course through stagnant muddy water.
A 55-year-old hunter presents with an indolent ulcer on his right index finger and painful swelling of his right axillary lymph nodes a week after skinning wild game.

Matches

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Answer

The meatpacker with undulating fevers matches with Brucella abortus. The farmer with retro-orbital headache and hepatitis after lambing matches with Coxiella burnetii. The adventure racer with conjunctival suffusion matches with Leptospira interrogans. The hunter with an ulceroglandular presentation matches with Francisella tularensis.
Each zoonotic pathogen possesses a distinct epidemiological niche and clinical signature. Brucella abortus is associated with meatpackers and unpasteurized dairy, causing undulating fevers and reticuloendothelial spread. Coxiella burnetii is aerosolized during livestock birthing, leading to Q fever. Leptospira interrogans is found in water contaminated by animal urine, classically causing conjunctival suffusion and myalgias. Francisella tularensis is transmitted via ticks or handling infected animals like rabbits, resulting in ulceroglandular disease.

Step-by-Step Solution

1
Identify the unique occupational or recreational exposure in each clinical vignette.
Meatpacking points to Brucella; lambing to Coxiella; stagnant mud/water to Leptospira; skinning wild game to Francisella.
Zoonotic pathogens have highly specific epidemiologic risk factors and transmission vectors.
2
Correlate the physical exam and laboratory findings with the suspected pathogen.
Undulating fevers and hepatosplenomegaly confirm Brucellosis. Culture-negative hepatitis and pneumonia confirm Q fever. Conjunctival suffusion and calf pain confirm Leptospirosis. Ulceroglandular disease confirms Tularemia.
Ensuring the clinical syndrome matches the epidemiological suspicion prevents misdiagnosis among diseases that may share generalized febrile symptoms.

Key Concept

Zoonotic Infectious Diseases: Epidemiological Exposures and Clinical Syndromes
Question 499Question →

Match each clinical presentation to the most likely associated rheumatologic condition.

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Items

A patient presenting with recurrent fetal loss, livedo reticularis, and a prolonged partial thromboplastin time (PTT) that fails to correct with normal plasma.
A patient presenting with progressive proximal muscle weakness, periorbital edema with a purplish hue, and erythematous papules on the knuckles.
A patient presenting with chronic lower back pain that improves with exercise, bilateral Achilles tendinitis, and acute unilateral anterior uveitis.
A patient presenting with severe xerophthalmia, xerostomia, accelerated dental caries, and episodic bilateral parotid gland swelling.
A patient presenting with daily spiking fevers, an evanescent salmon-colored maculopapular rash, and polyarthritis.

Matches

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Answer

1 matches Antiphospholipid syndrome, 2 matches Dermatomyositis, 3 matches Ankylosing spondylitis, 4 matches Sjögren syndrome, and 5 matches Adult-onset Still disease.
Each clinical vignette provides highly specific, pathognomonic features that unambiguously link to a single rheumatologic diagnosis.

Step-by-Step Solution

1
Analyze the first presentation: recurrent fetal loss, livedo reticularis, and prolonged PTT without correction.
Identify Antiphospholipid syndrome.
These are classic clinical and laboratory manifestations of Antiphospholipid syndrome.
2
Analyze the second presentation: proximal muscle weakness, periorbital purplish edema, and knuckle papules.
Identify Dermatomyositis.
Proximal weakness paired with heliotrope rash and Gottron papules is pathognomonic for Dermatomyositis.
3
Analyze the third presentation: inflammatory back pain, Achilles tendinitis, and uveitis.
Identify Ankylosing spondylitis.
These symptoms describe a seronegative spondyloarthropathy with characteristic enthesitis and extraarticular manifestations.
4
Analyze the fourth presentation: sicca symptoms, dental caries, and parotid swelling.
Identify Sjögren syndrome.
These are the hallmark exocrine gland dysfunctions of Sjögren syndrome.
5
Analyze the fifth presentation: spiking fevers, salmon-colored rash, and polyarthritis.
Identify Adult-onset Still disease.
This triad is the classic presentation of Adult-onset Still disease.

Key Concept

Recognition of classic clinical and laboratory manifestations of major rheumatologic conditions.
Question 500Question →

A primary care physician is reviewing the charts of four outpatients who presented with acute infectious or inflammatory symptoms. Match each patient's clinical presentation with the most appropriate, guideline-concordant initial management strategy to optimize antimicrobial stewardship and patient outcomes.

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Items

A 42-year-old man with 4 days of purulent nasal discharge, nasal congestion, and facial pressure without fever.
A 68-year-old man with a history of severe chronic obstructive pulmonary disease who reports a 2-day history of increased dyspnea, increased cough, and newly purulent sputum.
A 24-year-old healthy woman with 2 days of dysuria, urinary frequency, and suprapubic tenderness, without fever or costovertebral angle tenderness.
A 19-year-old man with a 2-day history of fever to 38.5∘C38.5^\circ\text{C}, tonsillar exudates, tender cervical lymphadenopathy, no cough, and a positive rapid antigen detection test for streptococcus.

Matches

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Answer

The patient with 4 days of sinus symptoms requires symptomatic therapy only. The patient with a COPD exacerbation requires a macrolide or tetracycline. The patient with uncomplicated cystitis requires nitrofurantoin or trimethoprim-sulfamethoxazole. The patient with confirmed streptococcal pharyngitis requires penicillin V or amoxicillin.
Appropriate antimicrobial stewardship involves targeting true bacterial infections while avoiding antibiotics for viral or self-limiting conditions. The patient with 4 days of sinus symptoms likely has a viral infection and needs symptomatic care. The patient with a COPD exacerbation showing purulent sputum and increased dyspnea meets the criteria for antibiotics (e.g., macrolides) to reduce failure rates. The young woman has uncomplicated cystitis, effectively treated with a short course of nitrofurantoin. The young man has confirmed Group A streptococcal pharyngitis, requiring a 10-day course of beta-lactam therapy to eradicate the organism and prevent acute rheumatic fever.

Step-by-Step Solution

1
Evaluate the clinical criteria for the patient with acute rhinosinusitis.
The duration of symptoms is 4 days, which is less than the 10-day threshold for bacterial infection.
Most cases of early rhinosinusitis are viral; antibiotics are withheld unless symptoms persist beyond 10 days, present with severe systemic signs, or exhibit 'double sickening'.
2
Assess the indications for antibiotics in the patient with a COPD exacerbation.
The patient has increased sputum purulence and increased dyspnea.
The presence of increased sputum purulence plus at least one other cardinal symptom (increased dyspnea or increased sputum volume) justifies antibiotic therapy.
3
Diagnose the young woman with lower urinary tract symptoms.
She has acute uncomplicated cystitis.
Classic symptoms of dysuria and frequency without systemic signs (fever, flank pain) are treated empirically with narrow-spectrum first-line agents.
4
Determine the treatment for the young man with a sore throat.
He has a confirmed Group A streptococcal infection.
A positive rapid antigen detection test in the context of typical symptoms (Centor criteria) requires full-course beta-lactam therapy.

Key Concept

Antimicrobial stewardship and guideline-concordant indications for antibiotic use in common outpatient clinical scenarios.
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