COMSAE PHASE 1 FORM 114 ACTUAL
EXAM QUESTIONS WITH ANSWERS
AND RATIONALES
QUESTION 1 – Cardiology
A 68-year-old male with a history of hypertension presents to the emergency
department with acute-onset severe chest pain radiating to his back. His blood
pressure is 180/110 mm Hg in the right arm and 140/90 mm Hg in the left arm.
Which of the following is the most appropriate initial diagnostic study?
A) CT angiography of the chest
B) Transthoracic echocardiogram
C) Electrocardiogram
D) Chest X-ray
E) Cardiac enzymes
Answer: A – CT angiography of the chest
Full Rationale:
• Option A (CT angiography of the chest) is correct. The patient's presentation of acute severe
chest pain radiating to the back with a significant blood pressure differential between arms
is classic for aortic dissection. CT angiography is the gold standard for diagnosis and
provides rapid, detailed imaging of the aorta.
• Option B (Transthoracic echocardiogram) – While useful for assessing aortic root
involvement, it has limited sensitivity for visualizing the descending aorta and is operator-
dependent. Not the optimal first choice.
• Option C (Electrocardiogram) – Should be obtained but is primarily to rule out myocardial
infarction. It does not diagnose aortic dissection and may be normal or show nonspecific
changes.
• Option D (Chest X-ray) – May show a widened mediastinum but is neither sensitive nor
specific for aortic dissection. Normal chest X-ray does not rule out dissection.
• Option E (Cardiac enzymes) – Helpful to rule out MI but do not diagnose aortic dissection.
Elevations may occur if dissection compromises coronary arteries.
,Key takeaway: Acute aortic dissection requires emergent imaging; CT angiography is the preferred
initial diagnostic modality due to high sensitivity, specificity, and rapid availability.
QUESTION 2 – Immunology
A 2-year-old child presents with recurrent sinopulmonary infections, chronic
diarrhea, and failure to thrive. Laboratory evaluation reveals low levels of all
immunoglobulins with absent antibody response to vaccination. Flow cytometry
shows normal B-cell counts but decreased plasma cells. Which of the following is
the most likely diagnosis?
A) Common variable immunodeficiency (CVID)
B) X-linked agammaglobulinemia
C) Selective IgA deficiency
D) Hyper-IgM syndrome
E) Severe combined immunodeficiency (SCID)
Answer: A – Common variable immunodeficiency (CVID)
Full Rationale:
• Option A (CVID) is correct. CVID is characterized by low levels of all immunoglobulins,
normal or low B-cell counts, and impaired antibody production. It typically presents in
childhood or early adulthood with recurrent infections, autoimmune manifestations, and
gastrointestinal complications. The presence of normal B cells but absent plasma cells is
classic.
• Option B (X-linked agammaglobulinemia) – Presents in infancy with recurrent infections
after maternal antibodies wane (around 6 months). Characterized by markedly decreased B
cells (<1%) and absent immunoglobulins. The normal B-cell count in this patient rules out
this diagnosis.
• Option C (Selective IgA deficiency) – Patients have isolated IgA deficiency with normal other
immunoglobulin levels and intact antibody responses to vaccines. This patient has
panhypogammaglobulinemia.
• Option D (Hyper-IgM syndrome) – Characterized by elevated or normal IgM and decreased
IgG, IgA, IgE due to defective class switching. This presentation with all immunoglobulins
low is not consistent.
• Option E (SCID) – Presents earlier in life (first few months) with severe infections, failure to
thrive, and profound lymphopenia. The presentation at 2 years with normal B cells is not
consistent.
,Key takeaway: CVID is a humoral immunodeficiency with low immunoglobulins, normal B cells, and
impaired antibody responses to vaccination.
QUESTION 3 – Pharmacology
A 45-year-old woman with hypertension is started on a new medication. She
returns 2 weeks later with a persistent dry cough. Her blood pressure is controlled
at 128/82 mm Hg. Which medication is most likely responsible for her symptoms?
A) Lisinopril
B) Amlodipine
C) Hydrochlorothiazide
D) Metoprolol
E) Clonidine
Answer: A – Lisinopril
Full Rationale:
• Option A (Lisinopril) is correct. Lisinopril is an ACE inhibitor, and a persistent dry cough is a
classic side effect occurring in 5-20% of patients. It is caused by accumulation of bradykinin
and substance P due to decreased breakdown by ACE.
• Option B (Amlodipine) – A calcium channel blocker. Common side effects include peripheral
edema, headache, and flushing. It is not associated with dry cough.
• Option C (Hydrochlorothiazide) – A thiazide diuretic. Side effects include electrolyte
abnormalities, hyperglycemia, and hyperuricemia. Not associated with dry cough.
• Option D (Metoprolol) – A beta-blocker. Side effects include bradycardia, fatigue, and
bronchospasm. Not associated with dry cough.
• Option E (Clonidine) – A central alpha-2 agonist. Side effects include sedation, dry mouth,
and rebound hypertension. Not associated with dry cough.
Key takeaway: Persistent dry cough is a hallmark side effect of ACE inhibitors (lisinopril, enalapril,
ramipril) due to bradykinin accumulation.
QUESTION 4 – Microbiology
A 25-year-old sexually active woman presents with vaginal itching, dysuria, and a
frothy, malodorous, greenish-yellow discharge. On microscopic examination of the
, discharge, motile organisms with flagella are observed. Which of the following is
the most appropriate treatment?
A) Metronidazole
B) Fluconazole
C) Doxycycline
D) Ceftriaxone
E) Acyclovir
Answer: A – Metronidazole
Full Rationale:
• Option A (Metronidazole) is correct. The clinical presentation of frothy, malodorous
greenish-yellow vaginal discharge with motile flagellated organisms on microscopy is
classic for trichomoniasis, caused by Trichomonas vaginalis. Metronidazole or tinidazole is
the treatment of choice.
• Option B (Fluconazole) – Treatment for vulvovaginal candidiasis, which typically presents
with thick, white, curd-like discharge and intense pruritus, not motile organisms.
• Option C (Doxycycline) – Treatment for chlamydia and other intracellular organisms. Not
effective against Trichomonas.
• Option D (Ceftriaxone) – Treatment for gonorrhea. Would be appropriate for purulent
discharge with gram-negative diplococci, not motile protozoa.
• Option E (Acyclovir) – Treatment for herpes simplex virus, which presents with painful
vesicles and ulcers, not frothy discharge.
Key takeaway: Trichomoniasis presents with frothy, malodorous discharge and motile organisms on
wet mount; treatment is metronidazole for both the patient and partner.
QUESTION 5 – Neurology
A 78-year-old man with a history of atrial fibrillation presents with sudden-onset
right-sided weakness and inability to speak. His symptoms began 2 hours ago.
Non-contrast head CT shows no evidence of hemorrhage. Which of the following
is the most appropriate next step?
A) Administer IV tissue plasminogen activator (tPA)
B) Start aspirin 325 mg daily
C) Administer heparin infusion
EXAM QUESTIONS WITH ANSWERS
AND RATIONALES
QUESTION 1 – Cardiology
A 68-year-old male with a history of hypertension presents to the emergency
department with acute-onset severe chest pain radiating to his back. His blood
pressure is 180/110 mm Hg in the right arm and 140/90 mm Hg in the left arm.
Which of the following is the most appropriate initial diagnostic study?
A) CT angiography of the chest
B) Transthoracic echocardiogram
C) Electrocardiogram
D) Chest X-ray
E) Cardiac enzymes
Answer: A – CT angiography of the chest
Full Rationale:
• Option A (CT angiography of the chest) is correct. The patient's presentation of acute severe
chest pain radiating to the back with a significant blood pressure differential between arms
is classic for aortic dissection. CT angiography is the gold standard for diagnosis and
provides rapid, detailed imaging of the aorta.
• Option B (Transthoracic echocardiogram) – While useful for assessing aortic root
involvement, it has limited sensitivity for visualizing the descending aorta and is operator-
dependent. Not the optimal first choice.
• Option C (Electrocardiogram) – Should be obtained but is primarily to rule out myocardial
infarction. It does not diagnose aortic dissection and may be normal or show nonspecific
changes.
• Option D (Chest X-ray) – May show a widened mediastinum but is neither sensitive nor
specific for aortic dissection. Normal chest X-ray does not rule out dissection.
• Option E (Cardiac enzymes) – Helpful to rule out MI but do not diagnose aortic dissection.
Elevations may occur if dissection compromises coronary arteries.
,Key takeaway: Acute aortic dissection requires emergent imaging; CT angiography is the preferred
initial diagnostic modality due to high sensitivity, specificity, and rapid availability.
QUESTION 2 – Immunology
A 2-year-old child presents with recurrent sinopulmonary infections, chronic
diarrhea, and failure to thrive. Laboratory evaluation reveals low levels of all
immunoglobulins with absent antibody response to vaccination. Flow cytometry
shows normal B-cell counts but decreased plasma cells. Which of the following is
the most likely diagnosis?
A) Common variable immunodeficiency (CVID)
B) X-linked agammaglobulinemia
C) Selective IgA deficiency
D) Hyper-IgM syndrome
E) Severe combined immunodeficiency (SCID)
Answer: A – Common variable immunodeficiency (CVID)
Full Rationale:
• Option A (CVID) is correct. CVID is characterized by low levels of all immunoglobulins,
normal or low B-cell counts, and impaired antibody production. It typically presents in
childhood or early adulthood with recurrent infections, autoimmune manifestations, and
gastrointestinal complications. The presence of normal B cells but absent plasma cells is
classic.
• Option B (X-linked agammaglobulinemia) – Presents in infancy with recurrent infections
after maternal antibodies wane (around 6 months). Characterized by markedly decreased B
cells (<1%) and absent immunoglobulins. The normal B-cell count in this patient rules out
this diagnosis.
• Option C (Selective IgA deficiency) – Patients have isolated IgA deficiency with normal other
immunoglobulin levels and intact antibody responses to vaccines. This patient has
panhypogammaglobulinemia.
• Option D (Hyper-IgM syndrome) – Characterized by elevated or normal IgM and decreased
IgG, IgA, IgE due to defective class switching. This presentation with all immunoglobulins
low is not consistent.
• Option E (SCID) – Presents earlier in life (first few months) with severe infections, failure to
thrive, and profound lymphopenia. The presentation at 2 years with normal B cells is not
consistent.
,Key takeaway: CVID is a humoral immunodeficiency with low immunoglobulins, normal B cells, and
impaired antibody responses to vaccination.
QUESTION 3 – Pharmacology
A 45-year-old woman with hypertension is started on a new medication. She
returns 2 weeks later with a persistent dry cough. Her blood pressure is controlled
at 128/82 mm Hg. Which medication is most likely responsible for her symptoms?
A) Lisinopril
B) Amlodipine
C) Hydrochlorothiazide
D) Metoprolol
E) Clonidine
Answer: A – Lisinopril
Full Rationale:
• Option A (Lisinopril) is correct. Lisinopril is an ACE inhibitor, and a persistent dry cough is a
classic side effect occurring in 5-20% of patients. It is caused by accumulation of bradykinin
and substance P due to decreased breakdown by ACE.
• Option B (Amlodipine) – A calcium channel blocker. Common side effects include peripheral
edema, headache, and flushing. It is not associated with dry cough.
• Option C (Hydrochlorothiazide) – A thiazide diuretic. Side effects include electrolyte
abnormalities, hyperglycemia, and hyperuricemia. Not associated with dry cough.
• Option D (Metoprolol) – A beta-blocker. Side effects include bradycardia, fatigue, and
bronchospasm. Not associated with dry cough.
• Option E (Clonidine) – A central alpha-2 agonist. Side effects include sedation, dry mouth,
and rebound hypertension. Not associated with dry cough.
Key takeaway: Persistent dry cough is a hallmark side effect of ACE inhibitors (lisinopril, enalapril,
ramipril) due to bradykinin accumulation.
QUESTION 4 – Microbiology
A 25-year-old sexually active woman presents with vaginal itching, dysuria, and a
frothy, malodorous, greenish-yellow discharge. On microscopic examination of the
, discharge, motile organisms with flagella are observed. Which of the following is
the most appropriate treatment?
A) Metronidazole
B) Fluconazole
C) Doxycycline
D) Ceftriaxone
E) Acyclovir
Answer: A – Metronidazole
Full Rationale:
• Option A (Metronidazole) is correct. The clinical presentation of frothy, malodorous
greenish-yellow vaginal discharge with motile flagellated organisms on microscopy is
classic for trichomoniasis, caused by Trichomonas vaginalis. Metronidazole or tinidazole is
the treatment of choice.
• Option B (Fluconazole) – Treatment for vulvovaginal candidiasis, which typically presents
with thick, white, curd-like discharge and intense pruritus, not motile organisms.
• Option C (Doxycycline) – Treatment for chlamydia and other intracellular organisms. Not
effective against Trichomonas.
• Option D (Ceftriaxone) – Treatment for gonorrhea. Would be appropriate for purulent
discharge with gram-negative diplococci, not motile protozoa.
• Option E (Acyclovir) – Treatment for herpes simplex virus, which presents with painful
vesicles and ulcers, not frothy discharge.
Key takeaway: Trichomoniasis presents with frothy, malodorous discharge and motile organisms on
wet mount; treatment is metronidazole for both the patient and partner.
QUESTION 5 – Neurology
A 78-year-old man with a history of atrial fibrillation presents with sudden-onset
right-sided weakness and inability to speak. His symptoms began 2 hours ago.
Non-contrast head CT shows no evidence of hemorrhage. Which of the following
is the most appropriate next step?
A) Administer IV tissue plasminogen activator (tPA)
B) Start aspirin 325 mg daily
C) Administer heparin infusion
