An adolescent girl with Crohn's disease, fever, and sore throat.

An adolescent female with a past medical history significant for Crohn's disease presented with fevers, tonsillitis without exudate, and tender posterior cervical lymphadenopathy. Laboratory results showed transaminitis, leukocytosis with a left shift, and atypical lymphocytes on a blood smear. The patient did not respond to supportive care or dexamethasone, necessitating a tonsillectomy and adenoidectomy. Although her presentation was consistent with infectious mononucleosis, diagnosis was not confirmed until Epstein-Barr virus (EBV) polymerase chain reaction (PCR) from tonsillar tissue was positive. False-negative results on the heterophile antibody test are common in pediatric populations and the detection of EBV antibodies is further complicated in immunocompromised patients. Studies indicate PCR is a more sensitive test, although there is no consensus regarding ideal material to use or quantitative levels necessitating intervention.