COMSAE Phase 1 (Form 115) 2026/2027
Practice Questions & Study Guide PDF |
Updated Test Bank with Verified Answers &
Rationales
• This 200-question COMSAE Phase 1 (Form 115) 2026/2027 practice exam mirrors
the structure and content of the official Comprehensive Osteopathic Medical Self-
Assessment Examination, covering all tested domains.
• Use this material by attempting each question independently before reviewing the
correct answer and detailed EXPERT RATIONALE to reinforce clinical reasoning and
osteopathic principles.
1. A 45-year-old male presents with substernal chest pain radiating to the left
arm, diaphoresis, and nausea. ECG shows ST-segment elevation in leads II, III,
and aVF. Which coronary artery is most likely occluded?
A. Left anterior descending artery
B. Left circumflex artery
C. Right coronary artery
D. Left main coronary artery
E. Posterior descending artery
C. Right coronary artery
EXPERT RATIONALE: ST elevation in leads II, III, and aVF indicates an inferior
myocardial infarction. The right coronary artery (RCA) supplies the inferior wall of
the left ventricle in the majority of patients (right-dominant circulation). Occlusion
of the RCA is the most common cause of inferior MI.
2. A 28-year-old female presents with fever, headache, stiff neck, and
photophobia. CSF analysis reveals cloudy fluid, elevated WBC with neutrophil
predominance, elevated protein, and decreased glucose. What is the most
likely causative organism?
,A. Cryptococcus neoformans
B. Listeria monocytogenes
C. Neisseria meningitidis
D. Herpes simplex virus
E. Mycobacterium tuberculosis
C. Neisseria meningitidis
EXPERT RATIONALE: The classic triad of fever, nuchal rigidity, and photophobia
with CSF showing neutrophilic pleocytosis, elevated protein, and decreased glucose
is consistent with bacterial meningitis. Neisseria meningitidis is the most common
cause in young adults and is associated with a petechial or purpuric rash.
Immediate empiric antibiotic therapy is required.
3. A 60-year-old male with a 40-pack-year smoking history presents with a
chronic productive cough and dyspnea. Spirometry reveals FEV1/FVC < 0.70
and FEV1 of 55% predicted. What is the most likely diagnosis?
A. Asthma
B. Pulmonary fibrosis
C. Restrictive lung disease
D. Chronic obstructive pulmonary disease
E. Bronchiectasis
D. Chronic obstructive pulmonary disease
EXPERT RATIONALE: COPD is characterized by an obstructive pattern on
spirometry with FEV1/FVC < 0.70 that is not fully reversible. A 40-pack-year smoking
history is the most significant risk factor. An FEV1 of 55% predicted places this
patient in GOLD Stage 2 (moderate COPD).
,4. A patient presents with somatic dysfunction at T4. On osteopathic
structural examination, the segment is found to be flexed, rotated right, and
side-bent right. How is this dysfunction named?
A. T4 ERSR
B. T4 FRSR
C. T4 FLSL
D. T4 NRSL
E. T4 ERSL
B. T4 FRSR
EXPERT RATIONALE: In osteopathic terminology, somatic dysfunction is named for
the position of the vertebra. This segment is Flexed (F), Rotated Right (RR), and Side-
bent Right (SR), making it T4 FRSR. This represents a Type II mechanics dysfunction,
as rotation and side-bending are to the same side.
5. A 7-year-old boy presents with a "slapped cheek" appearance and a lacy
reticular rash on the trunk and extremities. He has had low-grade fever and
mild upper respiratory symptoms for the past week. What is the causative
agent?
A. Rubella virus
B. Rubeola virus
C. Parvovirus B19
D. Human herpesvirus 6
E. Varicella-zoster virus
C. Parvovirus B19
EXPERT RATIONALE: Erythema infectiosum (Fifth disease) is caused by Parvovirus
B19. It classically presents with a "slapped cheek" facial rash followed by a lacy
reticular rash on the trunk. It is important to recognize because it can cause aplastic
, crisis in patients with hemolytic anemias such as sickle cell disease and is
dangerous in immunocompromised patients.
6. A 35-year-old female presents with diffuse joint pain, malar rash, oral
ulcers, and fatigue. Labs show ANA positive, anti-dsDNA positive, and low
complement levels. What is the most likely diagnosis?
A. Rheumatoid arthritis
B. Sjögren syndrome
C. Systemic lupus erythematosus
D. Dermatomyositis
E. Mixed connective tissue disease
C. Systemic lupus erythematosus
EXPERT RATIONALE: SLE is characterized by multisystem involvement including the
classic malar (butterfly) rash, arthritis, oral ulcers, serositis, and renal involvement.
The most specific antibodies for SLE are anti-dsDNA and anti-Smith. Low
complement (C3, C4) indicates complement consumption due to immune complex
deposition.
7. Which cranial nerve is responsible for the afferent limb of the corneal
reflex?
A. CN III
B. CN IV
C. CN V1
D. CN VII
E. CN VI
C. CN V1
Practice Questions & Study Guide PDF |
Updated Test Bank with Verified Answers &
Rationales
• This 200-question COMSAE Phase 1 (Form 115) 2026/2027 practice exam mirrors
the structure and content of the official Comprehensive Osteopathic Medical Self-
Assessment Examination, covering all tested domains.
• Use this material by attempting each question independently before reviewing the
correct answer and detailed EXPERT RATIONALE to reinforce clinical reasoning and
osteopathic principles.
1. A 45-year-old male presents with substernal chest pain radiating to the left
arm, diaphoresis, and nausea. ECG shows ST-segment elevation in leads II, III,
and aVF. Which coronary artery is most likely occluded?
A. Left anterior descending artery
B. Left circumflex artery
C. Right coronary artery
D. Left main coronary artery
E. Posterior descending artery
C. Right coronary artery
EXPERT RATIONALE: ST elevation in leads II, III, and aVF indicates an inferior
myocardial infarction. The right coronary artery (RCA) supplies the inferior wall of
the left ventricle in the majority of patients (right-dominant circulation). Occlusion
of the RCA is the most common cause of inferior MI.
2. A 28-year-old female presents with fever, headache, stiff neck, and
photophobia. CSF analysis reveals cloudy fluid, elevated WBC with neutrophil
predominance, elevated protein, and decreased glucose. What is the most
likely causative organism?
,A. Cryptococcus neoformans
B. Listeria monocytogenes
C. Neisseria meningitidis
D. Herpes simplex virus
E. Mycobacterium tuberculosis
C. Neisseria meningitidis
EXPERT RATIONALE: The classic triad of fever, nuchal rigidity, and photophobia
with CSF showing neutrophilic pleocytosis, elevated protein, and decreased glucose
is consistent with bacterial meningitis. Neisseria meningitidis is the most common
cause in young adults and is associated with a petechial or purpuric rash.
Immediate empiric antibiotic therapy is required.
3. A 60-year-old male with a 40-pack-year smoking history presents with a
chronic productive cough and dyspnea. Spirometry reveals FEV1/FVC < 0.70
and FEV1 of 55% predicted. What is the most likely diagnosis?
A. Asthma
B. Pulmonary fibrosis
C. Restrictive lung disease
D. Chronic obstructive pulmonary disease
E. Bronchiectasis
D. Chronic obstructive pulmonary disease
EXPERT RATIONALE: COPD is characterized by an obstructive pattern on
spirometry with FEV1/FVC < 0.70 that is not fully reversible. A 40-pack-year smoking
history is the most significant risk factor. An FEV1 of 55% predicted places this
patient in GOLD Stage 2 (moderate COPD).
,4. A patient presents with somatic dysfunction at T4. On osteopathic
structural examination, the segment is found to be flexed, rotated right, and
side-bent right. How is this dysfunction named?
A. T4 ERSR
B. T4 FRSR
C. T4 FLSL
D. T4 NRSL
E. T4 ERSL
B. T4 FRSR
EXPERT RATIONALE: In osteopathic terminology, somatic dysfunction is named for
the position of the vertebra. This segment is Flexed (F), Rotated Right (RR), and Side-
bent Right (SR), making it T4 FRSR. This represents a Type II mechanics dysfunction,
as rotation and side-bending are to the same side.
5. A 7-year-old boy presents with a "slapped cheek" appearance and a lacy
reticular rash on the trunk and extremities. He has had low-grade fever and
mild upper respiratory symptoms for the past week. What is the causative
agent?
A. Rubella virus
B. Rubeola virus
C. Parvovirus B19
D. Human herpesvirus 6
E. Varicella-zoster virus
C. Parvovirus B19
EXPERT RATIONALE: Erythema infectiosum (Fifth disease) is caused by Parvovirus
B19. It classically presents with a "slapped cheek" facial rash followed by a lacy
reticular rash on the trunk. It is important to recognize because it can cause aplastic
, crisis in patients with hemolytic anemias such as sickle cell disease and is
dangerous in immunocompromised patients.
6. A 35-year-old female presents with diffuse joint pain, malar rash, oral
ulcers, and fatigue. Labs show ANA positive, anti-dsDNA positive, and low
complement levels. What is the most likely diagnosis?
A. Rheumatoid arthritis
B. Sjögren syndrome
C. Systemic lupus erythematosus
D. Dermatomyositis
E. Mixed connective tissue disease
C. Systemic lupus erythematosus
EXPERT RATIONALE: SLE is characterized by multisystem involvement including the
classic malar (butterfly) rash, arthritis, oral ulcers, serositis, and renal involvement.
The most specific antibodies for SLE are anti-dsDNA and anti-Smith. Low
complement (C3, C4) indicates complement consumption due to immune complex
deposition.
7. Which cranial nerve is responsible for the afferent limb of the corneal
reflex?
A. CN III
B. CN IV
C. CN V1
D. CN VII
E. CN VI
C. CN V1
