Physician Assistant Clinical Knowledge 4 — Questions and Answers
Question 1: A 5-year-old boy is brought in with inspiratory stridor, fever, and a 'steeple sign' on anteroposterior neck X-ray. What is the most likely causative organism?
- Haemophilus influenzae type b
- Staphylococcus aureus
- Parainfluenza virus (Correct answer)
- Streptococcus pyogenes
Correct answer: Parainfluenza virus
Croup (laryngotracheobronchitis) is most commonly caused by parainfluenza virus and produces the classic steeple sign on AP neck X-ray.
Question 2: A 70-year-old woman presents with confusion, constipation, bone pain, and a serum calcium of 13.2 mg/dL. Intact PTH is elevated. What is the most likely diagnosis?
- Malignancy-associated hypercalcemia
- Primary hyperparathyroidism (Correct answer)
- Milk-alkali syndrome
- Vitamin D toxicity
Correct answer: Primary hyperparathyroidism
Elevated PTH with hypercalcemia is diagnostic of primary hyperparathyroidism, most commonly due to a single parathyroid adenoma.
Question 3: A 55-year-old male with type 2 diabetes develops burning pain and numbness in his feet bilaterally in a stocking-glove distribution. Which medication is first-line for diabetic peripheral neuropathy pain?
- Gabapentin
- Duloxetine (Correct answer)
- Amitriptyline
- Opioid analgesics
Correct answer: Duloxetine
Duloxetine (SNRI) and pregabalin are FDA-approved first-line treatments for diabetic peripheral neuropathic pain.
Question 4: A patient presents with acute onset of right lower quadrant pain, fever, and anorexia. On exam, there is rebound tenderness at McBurney's point. Which lab finding most supports the diagnosis of acute appendicitis?
- Elevated serum lipase
- Leukocytosis with left shift (Correct answer)
- Elevated serum bilirubin
- Thrombocytopenia
Correct answer: Leukocytosis with left shift
Leukocytosis with a left shift (increased band neutrophils) is the most consistent laboratory finding in acute appendicitis.
Question 5: A 62-year-old male with a 40 pack-year smoking history presents with progressive exertional dyspnea and chronic productive cough for >3 months per year over 2 consecutive years. Spirometry shows FEV1/FVC ratio of 0.62. What is the diagnosis?
- Asthma
- Chronic obstructive pulmonary disease (Correct answer)
- Restrictive lung disease
- Pulmonary fibrosis
Correct answer: Chronic obstructive pulmonary disease
COPD is defined by a post-bronchodilator FEV1/FVC ratio <0.70 with appropriate clinical history; chronic bronchitis meets the symptom criteria.
Question 6: A 22-year-old college student presents with fever, severe sore throat, and fatigue. Exam shows posterior cervical lymphadenopathy and splenomegaly. Monospot test is positive. What activity restriction is most important?
- Avoid all physical activity for 6 months
- No contact sports for at least 3-4 weeks due to splenic rupture risk (Correct answer)
- Bed rest for 2 weeks
- No swimming for 1 month
Correct answer: No contact sports for at least 3-4 weeks due to splenic rupture risk
Splenic rupture is the most serious complication of infectious mononucleosis; contact sports and heavy lifting should be avoided for at least 3-4 weeks.
Question 7: Which of the following is the most appropriate initial treatment for a patient with community-acquired pneumonia requiring hospitalization who has no comorbidities and no risk factors for resistant organisms?
- Vancomycin plus piperacillin-tazobactam
- Azithromycin monotherapy
- Beta-lactam plus macrolide, or respiratory fluoroquinolone alone (Correct answer)
- Levofloxacin plus metronidazole
Correct answer: Beta-lactam plus macrolide, or respiratory fluoroquinolone alone
IDSA/ATS guidelines recommend beta-lactam plus macrolide combination or a respiratory fluoroquinolone alone for non-ICU hospitalized CAP.
Physician Assistant Clinical Knowledge 4
A 5-year-old boy is brought in with inspiratory stridor, fever, and a 'steeple sign' on anteroposterior neck X-ray.
What is the most likely causative organism?