PetriKey

Disease

Infectious mononucleosis

EBV triad: fever, pharyngitis, lymphadenopathy

MON-oh-noo-klee-OH-sis

ebvherpesvirussalivayoung-adultsviral

High-yield clue

Fever, exudative pharyngitis, and posterior cervical lymphadenopathy with atypical lymphocytes and a positive heterophile (Monospot) is the classic mono clue.

Overview

A clinical syndrome most often from Epstein-Barr virus, studied for its classic triad, splenomegaly risk, and heterophile-antibody plus atypical-lymphocyte lab clues.

Classification

  • Viral syndrome
  • Herpesvirus (EBV) infection
  • Adolescents and young adults
  • Saliva-transmitted

Lab & identification clues

  • Positive heterophile antibody (Monospot) vocabulary
  • Reactive/atypical lymphocytes (Downey cells)
  • EBV VCA IgM serology concept

Associations

  • Saliva transmission ('kissing disease')
  • Splenomegaly with splenic-rupture caution
  • Amoxicillin-associated rash vocabulary
  • CMV as a heterophile-negative mimic

Commonly confused with

  • Streptococcal pharyngitis
  • CMV mononucleosis
  • Acute (primary) HIV syndrome

Your notes

Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.

OpenStax: Microbiology 2e organism classification foundationssourceNCBI Bookshelf: Medical Microbiology organism chapterssourceCDC: CDC disease and public-health topic pagessource