A 20-year-old, previously healthy man is brought to the emergency department due to fever, dysphagia, drooling, and poor coordination.  The symptoms started last week with mild fever, throat pain, and malaise.  He was able to eat some food but is afraid to drink fluids because he feels his “throat closing up.”  The patient went on an anthropology trip 2 months ago during which he explored several caves.  He has taken several over-the-counter analgesic medications without relief.  He does not recall any bites, scratches, or animal exposures.  The patient has received all standard immunizations and takes no medications.  He is febrile and tachycardic.  Examination shows dehydration, lethargy, and ataxia.  Saliva is pooling in his mouth.  No pharyngeal erythema or exudates are seen.

Item 1 of 2
Which of the following is the most likely diagnosis in this patient?

Item 2 of 2
The patient’s family is concerned about his prognosis.  Which of the following is the most accurate response regarding the recovery of this patient?

A 34-year-old man is brought to the emergency department due to 3 weeks of intermittent fever, headache, malaise, and night sweats.  Over the last few days, his headaches have worsened, and he has had blurry and double vision.  The patient uses injection drugs and was treated for staphylococcal endocarditis 4 years ago.  Temperature is 38.1 C (100.6 F), blood pressure is 150/100 mm Hg, pulse is 66/min, and respirations are 18/min.  BMI is 18.4 kg/m².  The patient is ill appearing and somnolent but easily arousable and oriented.  There are white plaques on the oropharyngeal mucosa and several skin lesions resembling molluscum contagiosum.  There is increased resistance to passive neck flexion.  Neurologic examination reveals leftward gaze restriction in the left eye but no other focal weakness or sensory loss.  Funduscopy reveals bilateral papilledema.  A noncontrast CT scan of the head shows no abnormalities.  The patient receives a lumbar puncture; results of the spinal fluid analysis are as follows:

Item 1 of 3

Which of the following is the best pharmacotherapy for this patient’s current condition?

Item 2 of 3

The patient is hospitalized and antimicrobial therapy is administered.  Further cerebrospinal fluid studies confirm the diagnosis, and the patient is also found to be HIV positive with a CD4 count of 26/mm³.  He had initial symptom relief but the severe headache returned, and he has also started to experience worsening nausea, vomiting, and lethargy.  Neurologic examination shows no new focal deficits.  Which of the following is the best next step in management of this patient?

Item 3 of 3

Two weeks after the treatment is started, the patient’s symptoms have improved and a repeat spinal fluid culture is negative.  Which of the following is the best next step in management of this patient?

A 30-year-old nurse comes to the occupational health clinic for evaluation.  He accidentally pricked his finger with a needle after drawing blood from a woman with a known history of intravenous drug abuse.  The nurse has no significant medical history and takes no medications.  According to his employment record, he received a series of 3 vaccinations for hepatitis B when first employed 5 years ago, tetanus immunization 2 years ago, and a yearly influenza vaccination.  However, a postimmunization titer for hepatitis B was never checked.  Today, the titer is found to be 5 mIU/mL (>10 mIU/mL is considered protective).  The source patient is currently in the hospital for treatment of endocarditis.  Laboratory testing of the source patient sent on the day of exposure shows the following results:

What is the most appropriate strategy to prevent infection in this health care worker?

A 62-year-old man is brought to the emergency department due to a hand wound and “not feeling very well.”  He cut his right hand while cleaning a tropical fish tank at his pet shop yesterday.  Although he applied topical antiseptics to the wound, it progressively became more painful and swollen.  The patient also developed fever and generalized weakness.  He has a history of type 2 diabetes mellitus, hypertension, and chronic kidney disease due to diabetic nephropathy.  He takes methotrexate and intermittent glucocorticoids for rheumatoid arthritis.  The patient drinks 1 or 2 cans of beer daily but does not use tobacco or illicit drugs.  Temperature is 38.9 C (102 F), blood pressure is 96/50 mm Hg, pulse is 114/min, and respirations are 22/min.  The patient appears ill.  The right hand is diffusely erythematous with hemorrhagic bullae surrounding a 3-cm dorsal laceration.  Laboratory results are as follows:

Which of the following is the most likely causative organism of this patient’s current condition?

An 84-year-old woman is brought to the emergency department due to headache, vomiting, and confusion that started yesterday.  She has a history of mild dementia, osteoarthritis, hypertension, and type 2 diabetes mellitus.  The patient was hospitalized 2 months ago due to lower extremity cellulitis.  She lives alone and receives help from a home health aide.  Temperature is 37.8 C (100 F), blood pressure is 118/70 mm Hg, and pulse is 96/min.  On physical examination, the patient is somnolent but follows instructions.  There are no focal neurologic deficits.  Cardiopulmonary and abdominal examinations are normal.  Laboratory studies reveal leukocytosis.  Lumbar puncture yields turbid fluid with the following cerebrospinal fluid findings:

Intravenous vancomycin and ceftriaxone are initiated empirically, and ampicillin is added.  Which of the following is the primary reason for using the additional antibiotic in this patient?

A 31-year-old, previously healthy man comes to the office due to yellowish discoloration of his eyes.  The patient reports that he has not felt well over the past 2 weeks and has had mild nausea, anorexia, and vague upper abdominal discomfort.  He takes no medications, drinks alcohol occasionally, and does not use tobacco or recreational substances.  The patient recently returned from a vacation in Thailand.  Temperature is 38 C (100.4 F), blood pressure is 120/74 mm Hg, and pulse is 68/min.  Physical examination is notable for scleral icterus and a tender and smooth liver edge palpable 2 cm below the right costal margin.  The remainder of the physical examination shows no abnormalities.  Laboratory results are as follows:

Abdominal ultrasonography reveals mild hepatic enlargement with no nodularity, gallstones, biliary ductal dilation, or ascites.

Item 1 of 3
In addition to recommending complete alcohol abstinence, which of the following is the most appropriate next step in management of this patient?

Item 2 of 3
The patient receives regular follow-up and laboratory testing over the next several weeks.  At the 6-week visit, he reports complete resolution of symptoms.  Repeat laboratory results are as follows:

Hepatitis B virus DNA at presentation was 200,000 IU/mL.  Which of the following is the best next step in management at present?

Item 3 of 3
The patient voices concern about the long-term prognosis.  Which of the following is the most appropriate response?

A 36-year-old man comes to the emergency department with severe pain in his left leg.  He is a carpenter and recalls that he had a small puncture wound from a wood splinter yesterday in his workshop.  The patient washed the wound and applied a small adhesive bandage.  This morning, he experienced severe pain in his left thigh and calf, and the pain has worsened since.  He has no other medical problems and takes no medications regularly.  His temperature is 39.4 C (103 F), blood pressure is 90/60 mm Hg, heart rate is 96/min, and respirations are 16/min.  Physical examination of his left lower extremity shows slight erythema and swelling of the thigh and calf with severe tenderness to palpation.  Two blisters are present on the posterior aspect of his proximal calf.

Item 1 of 2

Which of the following is the most likely organism responsible for this patient’s condition?

Item 2 of 2

While in the emergency department, the patient complains of increasing pain despite intravenous narcotic administration.  His blood pressure decreases to 70/50 mm Hg despite 2 L intravenous fluids.  Vasopressors are initiated.  His creatine phosphokinase level is 7,400 IU/L (normal 60-174 IU/L) and lactic acid level is 3.2 mmol/L (normal 0.7–1.8 mmol/L).  Blood cultures are pending.  Which of the following is the most appropriate next step in management of this patient?

A 43-year-old woman comes to the office due to 2 days of frequent “runny stools.”  She has not noticed blood or mucus in her stool but has had nausea, abdominal cramping, and malaise.  Yesterday, the patient returned from a week-long vacation in Honduras, where she saw notable sights, snorkeled in the Caribbean Sea, and ate food from street vendors.  Her medical history is significant for obesity, hypercholesterolemia, and gastroesophageal reflux disease.  The patient takes atorvastatin and omeprazole and has not recently used antibiotics.  She does not smoke tobacco or drink alcohol.  Temperature is 37.8 C (100 F), blood pressure is 130/80 mm Hg, pulse is 80/min, and respirations are 12/min.  BMI is 31 kg/m².  The patient appears uncomfortable.  The abdomen is soft and mildly tender but no guarding, rigidity, or rebound tenderness is present.  The remainder of the physical examination is normal.  Laboratory results are as follows:

Which of the following pathogens is the most likely cause of this patient’s symptoms?

A 47-year-old man comes to the office to establish medical care.  The patient feels well and reports no symptoms.  He has a history of hypertension treated with lifestyle modifications.  The patient does not use tobacco, alcohol, or recreational substances.  He is sexually active with both men and women and has had 4 sexual partners over the past year.  He uses condoms for contraception.  The patient has no history of sexually transmitted infections, and HIV testing a year ago was negative.  Blood pressure is 125/80 mm Hg and pulse is 78/min.  BMI is 24 kg/m².  Physical examination shows no abnormalities.  No jugular venous distension is present.  Cardiac auscultation reveals an S4 but no murmurs.  There is no peripheral edema.  Laboratory results are as follows:

Laboratory screening for syphilis, gonorrhea, and chlamydia is negative.  Colon cancer screening 2 years ago was normal.  In addition to recommending safe sexual practices, which of the following additional interventions is most appropriate for this patient?

A 40-year-old man comes to the office with concern of HIV infection.  The patient had unprotected anal intercourse with a new partner during a business trip a month ago.  A few days after the encounter, the patient learned that the partner was HIV positive.  The patient immediately visited an urgent care clinic and was tested for HIV using a combination p24 antigen/HIV-antibody immunoassay.  Although the test was negative and he has no symptoms, the patient feels anxious about the possibility of infection.  He has no prior medical problems and takes no medication.  The patient drinks alcohol on social occasions but does not use tobacco or illicit drugs.  Temperature is 37.1 C (98.8 F), blood pressure is 130/70 mm Hg, and pulse is 80/min.  No oropharyngeal erythema, exudate, or ulcers are present.  Lung auscultation is unremarkable and heart sounds are normal.  The abdomen is soft and nontender with no organomegaly.  Bowel sounds are normal.  No anal ulcers are present and genital examination is normal.

Item 1 of 2

Which of the following is the most appropriate next step in management of this patient’s concern about HIV infection?

Item 2 of 2

Repeat testing for HIV antigen and antibody is positive.  The patient’s CD4+ count is 320/mm³ and serum HIV RNA (viral load) is 500,000 copies/mL.  The risks and benefits of antiretroviral therapy are discussed, and the decision is made to initiate treatment.  In addition to genotypic drug-resistance testing, what additional laboratory test should be obtained before initiating antiretroviral therapy?

A 62-year-old man comes to the office for follow-up after recent hospitalization.  Two weeks ago, the patient went to the emergency department due to a 3-day history of fever, chills, dysuria, urinary frequency, and low back pain.  Evaluation showed a tender and swollen prostate, leukocytosis, pyuria, and bacteriuria.  Treatment for acute bacterial prostatitis was begun with intravenous antibiotics.  Blood and urine cultures returned positive for Escherichia coli sensitive to all tested antibiotics.  The patient was discharged after clinical improvement and was prescribed a 6-week course of oral ciprofloxacin.  He has had no fever, and urinary symptoms have resolved, but over the last 2 days, he has had mild abdominal cramps and 4 or 5 watery bowel movements per day with no blood or mucus.  Other medical conditions include hypertension and type 2 diabetes mellitus.  On examination, the patient is afebrile, and other vital signs are within normal limits.  There is mild periumbilical tenderness, but physical examination is otherwise unremarkable.  Laboratory studies show a leukocyte count of 14,500/mm³ and serum creatinine level of 0.9 mg/dL.  Stool testing is positive for Clostridioides difficile.

Item 1 of 2
In addition to initiating fidaxomicin therapy for treatment of C difficile infection, which of the following is the most appropriate next step in management of this patient?

Item 2 of 2
The patient returns to the office 3 weeks later and says that he took oral fidaxomicin as prescribed but stopped a week ago after the abdominal cramps and diarrhea improved.  Since yesterday, he has had intermittent lower abdominal discomfort and several episodes of watery bowel movements.  The patient reports no urinary symptoms and continues to take trimethoprim-sulfamethoxazole for the prostatitis.  Temperature is 37.2 C (99 F), blood pressure is 122/80 mm Hg, and pulse is 85/min.  Physical examination shows mild tenderness in the left lower quadrant with no guarding or rebound tenderness and normal bowel sounds.  Laboratory studies show a leukocyte count of 14,300/mm³.  Which of the following is the most likely cause of this patient’s symptoms?

An 82-year-old woman comes to the office due to a day of low-grade fever and rash.  Two days ago, the patient began having stabbing pain in her left flank.  Over the following day, this area became itchy and red.  The patient tried over-the-counter topical hydrocortisone and lidocaine but had no relief.  She has a history of hypothyroidism, type 2 diabetes mellitus, rheumatoid arthritis, and osteoporosis.  She was recently hospitalized for sepsis secondary to a urinary tract infection and discharged on oral ciprofloxacin, which she completed yesterday.  The patient has no history of drug allergy.  Her other medications include low-dose aspirin, alendronate, levothyroxine, glipizide, low-dose prednisone, calcium, and vitamin D supplementation.  She does not smoke, consume alcohol, or use illicit drugs.  Temperature is 37.8 C (100 F), blood pressure is 124/72 mm Hg, pulse is 92/min, and respirations are 14/min.  Examination of her left flank shows bright patchy erythema, excoriations, and several fluid-filled blisters.

Item 1 of 2

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

Item 2 of 2

The appropriate treatment was initiated.  Over the next 24 hours, the patient has progressive pain in the area of the skin lesions and is admitted to the hospital for pain control.  On reexamination, the rash has progressed and now also involves the right flank and lower back.  The rash is patchy with bright red erythema and blisters without crusting.  Which of the following is the most appropriate strategy to reduce the risk of exposure to health care personnel?

A 26-year-old woman comes to the clinic for routine HIV care.  She mentions that she had “low platelets” when she was tested 2 months ago in an emergency department following a minor motor vehicle collision.  The patient has no mucosal bleeding and does not bruise easily.  Her menses have been normal.  Two years ago, she was diagnosed with HIV after attempting to donate blood.  The patient has not begun antiretroviral therapy, and she takes a multivitamin daily.  Her temperature is 36.9 C (98.4 F), blood pressure is 116/78 mm Hg, pulse is 70/min, and respirations are 14/min.  On examination, the patient’s nasal and oropharyngeal mucosae appear normal.  Her abdomen is nontender and nondistended, but the tip of the spleen is palpable on inspiration.  There are no purpura or petechiae.  Laboratory results are as follows:

Item 1 of 2

Which of the following treatments is the best next step in management?

Item 2 of 2

The patient begins antiretroviral therapy with a 3-drug regimen.  Viral load and CD4 cell count are monitored as recommended.  Assuming she is able to adhere to the 3-drug regimen, which of the following best represents her expected HIV viral load after 6 months of treatment?