Internal Medicine

Autoantibody testing plays a critical role in the diagnosis and classification of connective tissue diseases. Match each specific autoantibody profile to the rheumatologic condition it is most strongly associated with.

Match each classic peripheral blood smear finding to the hematologic disorder with which it is most characteristically associated.

Match the following distinct peripheral blood smear findings to their most likely underlying clinical condition or pathophysiology.

A 29-year-old man is brought to the emergency department by his partner due to the sudden onset of right-sided weakness and difficulty speaking that began $2$ hours ago. Over the past $6$ months, the patient has experienced profound fatigue and intermittent episodes of difficulty swallowing. He also reports vague, episodic abdominal pain and passing very dark urine, which he notes is most prominent during his first void of the morning. His temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure is $132/82 \text{ mm Hg}$, pulse is $98/\text{min}$, and respiratory rate is $16/\text{min}$. Physical examination reveals mild scleral icterus, right-sided hemiparesis, and expressive aphasia. The abdomen is soft and non-tender. Laboratory studies show:

Hemoglobin: $7.8 \text{ g/dL}$
Mean corpuscular volume: $99 \text{ fL}$
Platelet count: $122,000/\text{mm}^3$
Leukocyte count: $3,800/\text{mm}^3$
Lactate dehydrogenase: $2,100 \text{ U/L}$
Total bilirubin: $3.8 \text{ mg/dL}$
Direct bilirubin: $0.5 \text{ mg/dL}$
Haptoglobin: $<10 \text{ mg/dL}$
Creatinine: $1.3 \text{ mg/dL}$
Direct antiglobulin (Coombs) test: Negative

A non-contrast CT scan of the head shows no acute intracranial hemorrhage. Which of the following is the most appropriate diagnostic test to establish the underlying etiology of this patient's presentation?

A 22-year-old man with type 1 diabetes mellitus is brought to the emergency department with abdominal pain, nausea, and confusion. He recently had a respiratory infection. His blood pressure is 90/60 mm Hg, and heart rate is 122/min. Point-of-care capillary blood glucose is 550 mg/dL. An arterial blood gas reveals a pH of 7.15 and a bicarbonate of 10 mEq/L. The remainder of his laboratory results, including a basic metabolic panel, are pending. Arrange the following management steps in the most appropriate chronological order for this patient.

A 39-year-old man is evaluated in the hospital on hospital day 3. He was admitted for community-acquired pneumonia after presenting with a high fever, productive cough, and right lower lobe consolidation on chest radiography. On admission, he was empirically started on intravenous ceftriaxone and oral azithromycin. Over the past 48 hours, his fever has resolved, his respiratory symptoms have significantly improved, and he is eating a regular diet. His temperature is 37.1 C (98.8 F), blood pressure is 124/82 mm Hg, pulse is 76/min, and respiratory rate is 14/min. Sputum and blood cultures obtained on admission both grow Streptococcus pneumoniae. Antimicrobial susceptibility testing reveals the isolate is susceptible to amoxicillin, ceftriaxone, levofloxacin, and linezolid. Which of the following is the most appropriate next step in pharmacotherapy?

Hematologic malignancies frequently manifest with unique peripheral blood smear abnormalities that reflect the underlying pathophysiologic disruption of normal hematopoiesis. Match each of the following patient vignettes to the most likely underlying hematologic diagnosis.

A 62-year-old female presents to the emergency room accompanied by her daughter, who reports that her mother has been increasingly confused and feverish over the preceding 24 hours. Her past medical history is notable for a deceased-donor renal transplant performed three years ago, maintained on a regimen of tacrolimus and mycophenolate mofetil. Vital signs show a temperature of 39.4°C (102.9°F), blood pressure of 110/65 mm Hg, pulse of 112/min, and respirations of 20/min. Physical examination reveals marked nuchal rigidity and a positive Kernig sign. The patient is somnolent but arousable to verbal stimuli. There are no focal motor deficits, but fundoscopic examination is deferred due to poor patient cooperation. The clinical team suspects acute bacterial meningitis and prepares to initiate the management protocol. Arrange the following critical next steps in the most appropriate chronological sequence.

A 28-year-old man presents to a primary care clinic requesting an HIV test. He reports having unprotected receptive anal intercourse with a new male partner two months ago. He currently has no symptoms, and his physical examination is unremarkable. Arrange the following steps in the most appropriate chronological sequence for the diagnosis and initial management of this patient, assuming all subsequent tests confirm the presence of HIV.

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

A $68$-year-old man comes to the clinic due to a $3$-month history of progressively worsening lower back pain and severe fatigue. He also reports new-onset constipation over the past two weeks. He has no prior medical history and takes no medications. Vital signs are within normal limits. Physical examination shows pallor and tenderness to palpation over the lumbar spine. Laboratory studies show:

A peripheral blood smear demonstrates red blood cells that appear stacked on top of one another. Which of the following is the most likely diagnosis?

During morning rounds on the medical ward, a physician reviews the progress of a 72-year-old male patient. The patient was admitted 72 hours ago due to fever and acute delirium secondary to a catheter-associated urinary tract infection. Upon admission, the urinary catheter was removed, and broad-spectrum empiric therapy with intravenous vancomycin and piperacillin-tazobactam was initiated. Currently, the patient is afebrile, hemodynamically stable, and eating a regular diet. His mental status has completely returned to baseline. Final culture results from both blood and urine reveal growth of *Enterococcus faecalis*. Susceptibility panels indicate the organism is sensitive to ampicillin, vancomycin, linezolid, and daptomycin. Based on the culture results and clinical improvement, which of the following is the most appropriate pharmacological intervention for this patient?

Match each chemotherapeutic agent with its most characteristic adverse effect.

A 65-year-old man with a history of ischemic heart disease, hypertension, and recurrent ventricular arrhythmias comes to the clinic reporting progressive fatigue, muscle aches, and joint pain for the past 4 weeks. He was hospitalized 5 months ago for sustained ventricular tachycardia and was discharged on a new oral medication. His temperature is 37.8°C (100.0°F). Physical examination shows symmetrical swelling and tenderness in the metacarpophalangeal and proximal interphalangeal joints of both hands. There is a mild erythematous rash over his cheeks and the bridge of his nose. Laboratory studies show a normal complete blood count and normal renal function. Antinuclear antibody (ANA) and anti-histone antibodies are positive. Anti-double-stranded DNA (anti-dsDNA) antibodies are negative. Which of the following is the most appropriate next step in the management of this patient?

A 71-year-old male is currently on the medical ward receiving treatment for a severe skin and soft tissue infection complicated by bloodstream invasion. He was admitted 72 hours ago with marked swelling, warmth, and purulence of his left forearm following a minor abrasion. At the time of admission, he was febrile and hypotensive, prompting the initiation of broad-spectrum coverage with intravenous vancomycin and cefepime. He has since hemodynamically stabilized and is now afebrile. The microbiology laboratory reports that both sets of blood cultures obtained at admission are positive for Staphylococcus aureus. Susceptibility testing reveals the organism is susceptible to oxacillin, cefazolin, clindamycin, and vancomycin, but resistant to penicillin. Which of the following is the most appropriate modification to his antimicrobial regimen?

Match the following patients presenting with malaria exposure or active infection to their most appropriate pharmacological management.

A 68-year-old woman is evaluated in the intensive care unit on hospital day 3. She was admitted with fever, left-sided flank pain, and hypotension. She was diagnosed with septic shock secondary to acute complicated pyelonephritis. Empiric therapy with intravenous piperacillin-tazobactam and aggressive fluid resuscitation were initiated. Her clinical status has improved, and vasopressor support was successfully discontinued yesterday. Today, her temperature is $37.9^{\circ} \text{C}$ ($100.2^{\circ} \text{F}$), blood pressure is $118/72 \text{ mmHg}$, and heart rate is $88/\text{min}$. Blood and urine cultures collected on admission both grow *Escherichia coli*. The susceptibility profile of the isolate is reported as follows:

Which of the following is the most appropriate next step in the pharmacologic management of this patient's infection?

A 42-year-old woman presents to the clinic with a 5-month history of progressive fatigue, a 6-kg (13.2-lb) weight gain, and worsening cold intolerance. She also notes that her menstrual cycles have become irregular, occurring every 45 to 60 days. She takes no medications. Her blood pressure is 108/68 mm Hg, and her pulse is 56/min. Physical examination reveals dry skin and delayed relaxation of the deep tendon reflexes. Visual fields are full to confrontation.

Laboratory studies show:
Thyroid-stimulating hormone (TSH): $1.2 \text{ mU/L}$ (Reference: $0.4-4.0 \text{ mU/L}$)
Free thyroxine (T4): $0.4 \text{ ng/dL}$ (Reference: $0.9-1.7 \text{ ng/dL}$)

Which of the following is the most appropriate next step in patient management?

A 24-year-old medical student accidentally sustains a percutaneous needlestick injury from a hollow-bore needle immediately after drawing blood from a hospitalized patient. The source patient's human immunodeficiency virus (HIV), hepatitis B, and hepatitis C statuses are currently unknown. Arrange the following steps in the most appropriate chronological sequence for the immediate management of this occupational exposure.

A $62$-year-old woman is evaluated on postoperative day $5$ following a right hemicolectomy for stage III colon adenocarcinoma. She has been receiving subcutaneous unfractionated heparin for deep vein thrombosis prophylaxis. Today, she reports sudden-onset right lower extremity pain and swelling, mild shortness of breath, and nausea. Vital signs are temperature $37.8^\circ \text{C}$ ($100^\circ \text{F}$), blood pressure $135/85\text{ mmHg}$, pulse $102\text{ /min}$, and respirations $20\text{ /min}$. Physical examination shows a swollen, erythematous, and tender right calf. The abdomen is mildly distended but non-tender with hypoactive bowel sounds. Lungs are clear to auscultation. Laboratory studies show:

Hemoglobin: $11.2\text{ g/dL}$
Platelet count: $65,000/\mu\text{L}$ (baseline prior to surgery was $250,000/\mu\text{L}$)
Leukocyte count: $8,500/\mu\text{L}$

Prothrombin time (PT): $12.5\text{ seconds}$
Partial thromboplastin time (PTT): $32\text{ seconds}$

Sodium: $138\text{ mEq/L}$
Potassium: $4.2\text{ mEq/L}$
Blood urea nitrogen: $16\text{ mg/dL}$
Creatinine: $0.9\text{ mg/dL}$

Lower extremity venous duplex ultrasonography confirms an acute deep vein thrombosis in the right popliteal vein. Which of the following is the most appropriate next step in management?