Mononucleosis-like illness with exudative pharyngitis and palatal petechiae is most commonly due to infection with which virus?

Mononucleosis-like illness with exudative pharyngitis and palatal petechiae is most commonly due to infection with which virus?

• A. Parvovirus B19
• B. Cytomegalovirus
• C. Adenovirus
• D. Epstein-Barr Virus

Answer: (D)

Fever, tonsillar exudates, and a mono-like illness with palatal petechiae point to Epstein-Barr virus as the most likely cause. EBV is the classic agent behind infectious mononucleosis, especially in adolescents and young adults, and mucosal signs like exudative pharyngitis along with palatal petechiae are commonly taught as characteristic findings. The body's B-cell infection by EBV triggers a strong T-cell–mediated response, leading to atypical lymphocytosis and a positive heterophile (Monospot) test in many cases, which helps confirm the diagnosis. Other viruses can mimic mono, but they fit less well: parvovirus B19 tends to present differently (often with rash or anemia and not the typical palatal petechiae); CMV can cause a mono-like syndrome but usually has a negative heterophile test and milder pharyngitis; adenovirus can cause exudative pharyngitis but palatal petechiae are less typical and systemic features differ. So the combination of an infectious mononucleosis–type illness with exudative pharyngitis and palatal petechiae most strongly suggests EBV infection, with diagnostic testing and supportive management accordingly.

Fever, tonsillar exudates, and a mono-like illness with palatal petechiae point to Epstein-Barr virus as the most likely cause. EBV is the classic agent behind infectious mononucleosis, especially in adolescents and young adults, and mucosal signs like exudative pharyngitis along with palatal petechiae are commonly taught as characteristic findings. The body's B-cell infection by EBV triggers a strong T-cell–mediated response, leading to atypical lymphocytosis and a positive heterophile (Monospot) test in many cases, which helps confirm the diagnosis.

Other viruses can mimic mono, but they fit less well: parvovirus B19 tends to present differently (often with rash or anemia and not the typical palatal petechiae); CMV can cause a mono-like syndrome but usually has a negative heterophile test and milder pharyngitis; adenovirus can cause exudative pharyngitis but palatal petechiae are less typical and systemic features differ.

So the combination of an infectious mononucleosis–type illness with exudative pharyngitis and palatal petechiae most strongly suggests EBV infection, with diagnostic testing and supportive management accordingly.