NR 511 Final Exam: Differential Diagnosis - Chamberlain
University Updated and Latest Questions and Correct
Answers with Rationale
1. A 45-year-old female presents with sharp right upper quadrant (RUQ) pain that radiates to the right
scapula. On physical examination, she has a positive Murphy’s sign. What is the most likely primary
differential diagnosis?
A. Acute Pancreatitis
B. Nephrolithiasis
C. Peptic Ulcer Disease
D. Acute Cholecystitis
Correct Answer: D
Rationale: Acute cholecystitis typically presents with RUQ pain and radiation to the right shoulder or
scapula. A positive Murphy’s sign is highly specific for gallbladder inflammation during palpation. The
differential must consider other abdominal pathologies but the location is classic for biliary issues.
Diagnostic confirmation is usually achieved through an abdominal ultrasound. Management often
involves surgical consultation and supportive care for the inflammation.
2. Which of the following metrics defines the ability of a diagnostic test to correctly identify those patients
who actually have the disease?
A. Specificity
B. Sensitivity
C. Positive Predictive Value
D. Negative Predictive Value
,Correct Answer: B
Rationale: Sensitivity refers to the proportion of actual positives that are correctly identified as such by
the test. A highly sensitive test is useful for screening because it minimizes false negatives. In contrast,
specificity measures the test’s ability to identify those without the disease. Understanding these metrics
is vital for interpreting diagnostic results in clinical practice. Clinicians rely on sensitivity to rule out
conditions when the result is negative.
3. A patient presents with a ‘herald patch’ followed by a Christmas tree pattern rash on their back. What is
the most probable diagnosis?
A. Tinea Corporis
B. Guttate Psoriasis
C. Pityriasis Rosea
D. Secondary Syphilis
Correct Answer: C
Rationale: Pityriasis Rosea is characterized by an initial herald patch followed by smaller lesions in a
cleavage line distribution. This skin condition is usually self-limiting and may last six to eight weeks. It is
important to differentiate this from secondary syphilis which involves the palms and soles. Pruritus is
common and can be managed with topical steroids or antihistamines. The viral etiology is suspected but
not definitively proven in all clinical cases.
4. A 22-year-old male presents with a sore throat, fever, and cervical lymphadenopathy. His Centor Score is
4. What is the recommended next step in management?
A. Recommend supportive care only
B. Start empiric antibiotics immediately
, C. Perform a Rapid Antigen Detection Test (RADT)
D. Order a chest X-ray
Correct Answer: C
Rationale: The Centor Criteria help clinicians estimate the probability of Group A Streptococcal (GAS)
pharyngitis. A score of 4 indicates a high probability, suggesting that testing or treatment is warranted.
Current guidelines recommend confirming the diagnosis with a RADT before initiating antibiotics. If the
RADT is negative in a child, a follow-up throat culture is necessary. This approach helps reduce the
unnecessary use of antibiotics in viral pharyngitis cases.
5. When interpreting pulmonary function tests (PFTs), a decreased FEV1/FVC ratio (less than 0.70) is
diagnostic of which type of lung disease?
A. Restrictive disease
B. Infectious disease
C. Obstructive disease
D. Vascular disease
Correct Answer: C
Rationale: An FEV1/FVC ratio below 0.70 signifies airflow limitation characteristic of obstructive lung
diseases. Common examples include asthma and chronic obstructive pulmonary disease (COPD). In
restrictive diseases, the ratio usually remains normal or is slightly increased because both volumes
decrease. Differentiating between these patterns is essential for selecting appropriate inhaler therapies.
Clinical correlation with the patient’s smoking history and symptoms is always required.
University Updated and Latest Questions and Correct
Answers with Rationale
1. A 45-year-old female presents with sharp right upper quadrant (RUQ) pain that radiates to the right
scapula. On physical examination, she has a positive Murphy’s sign. What is the most likely primary
differential diagnosis?
A. Acute Pancreatitis
B. Nephrolithiasis
C. Peptic Ulcer Disease
D. Acute Cholecystitis
Correct Answer: D
Rationale: Acute cholecystitis typically presents with RUQ pain and radiation to the right shoulder or
scapula. A positive Murphy’s sign is highly specific for gallbladder inflammation during palpation. The
differential must consider other abdominal pathologies but the location is classic for biliary issues.
Diagnostic confirmation is usually achieved through an abdominal ultrasound. Management often
involves surgical consultation and supportive care for the inflammation.
2. Which of the following metrics defines the ability of a diagnostic test to correctly identify those patients
who actually have the disease?
A. Specificity
B. Sensitivity
C. Positive Predictive Value
D. Negative Predictive Value
,Correct Answer: B
Rationale: Sensitivity refers to the proportion of actual positives that are correctly identified as such by
the test. A highly sensitive test is useful for screening because it minimizes false negatives. In contrast,
specificity measures the test’s ability to identify those without the disease. Understanding these metrics
is vital for interpreting diagnostic results in clinical practice. Clinicians rely on sensitivity to rule out
conditions when the result is negative.
3. A patient presents with a ‘herald patch’ followed by a Christmas tree pattern rash on their back. What is
the most probable diagnosis?
A. Tinea Corporis
B. Guttate Psoriasis
C. Pityriasis Rosea
D. Secondary Syphilis
Correct Answer: C
Rationale: Pityriasis Rosea is characterized by an initial herald patch followed by smaller lesions in a
cleavage line distribution. This skin condition is usually self-limiting and may last six to eight weeks. It is
important to differentiate this from secondary syphilis which involves the palms and soles. Pruritus is
common and can be managed with topical steroids or antihistamines. The viral etiology is suspected but
not definitively proven in all clinical cases.
4. A 22-year-old male presents with a sore throat, fever, and cervical lymphadenopathy. His Centor Score is
4. What is the recommended next step in management?
A. Recommend supportive care only
B. Start empiric antibiotics immediately
, C. Perform a Rapid Antigen Detection Test (RADT)
D. Order a chest X-ray
Correct Answer: C
Rationale: The Centor Criteria help clinicians estimate the probability of Group A Streptococcal (GAS)
pharyngitis. A score of 4 indicates a high probability, suggesting that testing or treatment is warranted.
Current guidelines recommend confirming the diagnosis with a RADT before initiating antibiotics. If the
RADT is negative in a child, a follow-up throat culture is necessary. This approach helps reduce the
unnecessary use of antibiotics in viral pharyngitis cases.
5. When interpreting pulmonary function tests (PFTs), a decreased FEV1/FVC ratio (less than 0.70) is
diagnostic of which type of lung disease?
A. Restrictive disease
B. Infectious disease
C. Obstructive disease
D. Vascular disease
Correct Answer: C
Rationale: An FEV1/FVC ratio below 0.70 signifies airflow limitation characteristic of obstructive lung
diseases. Common examples include asthma and chronic obstructive pulmonary disease (COPD). In
restrictive diseases, the ratio usually remains normal or is slightly increased because both volumes
decrease. Differentiating between these patterns is essential for selecting appropriate inhaler therapies.
Clinical correlation with the patient’s smoking history and symptoms is always required.
