AANP Family Nurse Practitioner (FNP) Certification ExamDiagnosisEasy
A 28-year-old female presents with a 3-week history of fatigue, generalized weakness, sore throat, and swollen lymph nodes in her posterior cervical region. Physical examination reveals tonsillar exudates, splenomegaly, and a maculopapular rash on her trunk. Which of the following diagnostic tests is most appropriate to confirm the suspected diagnosis?
- AComplete Blood Count (CBC) with differential
- BMonospot test
- CStreptococcal pharyngitis rapid antigen detection test (RADT)
- DEpstein-Barr Virus (EBV) viral load by PCR
Show answer & explanationAnswer & explanation
Correct answer: B. Monospot test
The patient's constellation of symptoms, including fatigue, sore throat, lymphadenopathy (especially posterior cervical), splenomegaly, and rash, is highly suggestive of infectious mononucleosis. The Monospot test is the most appropriate initial diagnostic test for this condition.
Why the other options are wrong
- A. While a CBC may show atypical lymphocytes, it is not specific enough to confirm infectious mononucleosis as the primary diagnostic test.
- C. RADT is used to diagnose streptococcal pharyngitis, which can mimic some symptoms but does not explain the splenomegaly or rash, and the Monospot is more specific for mono.
- D. EBV viral load by PCR is typically used in immunocompromised patients or for difficult-to-diagnose cases, not as a first-line diagnostic for typical infectious mononucleosis.
Infectious Mononucleosis Diagnosis
Infectious mononucleosis, caused primarily by Epstein-Barr Virus (EBV), is diagnosed based on clinical presentation and confirmed with a Monospot test which detects heterophile antibodies.
- Classic triad: fever, pharyngitis, lymphadenopathy.
- Commonly presents with fatigue, splenomegaly, and sometimes a rash.
- Monospot test is the primary diagnostic tool.
Memory trick: MonoSpotting the Mono Monster!