A patient presents with bilateral cervical lymphadenopathy, fever, and pinpoint hemorrhagic spots on the palate. Which diagnostic test should be ordered first?

Correct answer: B. Monospot test (heterophile antibody test)

• A. A CBC with differential would show atypical lymphocytes (Downey cells) in mononucleosis and is supportive, but the Monospot is the specific initial test for this clinical picture.
• B. CORRECT. The clinical triad of fever, bilateral lymphadenopathy, and palatal petechiae is classic for infectious mononucleosis (EBV infection). The Monospot (Paul-Bunnell) test detects heterophile antibodies and is the rapid screening test of choice for confirming EBV mononucleosis.
• C. Throat culture identifies bacterial streptococcal pharyngitis — while Strep can coexist, the full clinical picture (lymphadenopathy + palatal petechiae + fever) points to mononucleosis.
• D. VDRL tests for syphilis. Secondary syphilis can cause lymphadenopathy and a rash, but palatal petechiae are not characteristic, and syphilis does not produce this specific triad.