Abstract
Penicillin-based antibiotics (PCs) are contraindicated for infectious mononucleosis because rashes occur as an adverse reaction in a high percentage of cases. On the other hand, PCs are the first-line choice of treatment for acute bacterial pharyngitis/tonsillitis, where the main causative organism is group-A beta-hemolytic streptococcus. We recently experienced a case of infectious mononucleosis accompanying a group-A beta-hemolytic streptococcal infection. The patient was a 20-year-old female with chief complaints of pharyngeal pain and pyrexia. Pus was observed on the epipharynx and palatine tonsils, and the results of a rapid test for group-A beta-hemolytic streptococcus were positive. An automated hematology analyzer revealed a lymphocyte-dominant increase in white blood cells, so we performed liver function tests and a test for Epstein-Barr (EB) virus antibodies and also administered ceftriaxone. The bacterial tests confirmed group-A beta-hemolytic streptococcus in the epipharynx and palatine tonsils (3 +). Blood tests showed decreased liver function, atypical lymphocytes and EB virus infection,so infectious mononucleosis was also diagnosed. When selecting an antibiotic for the treatment of acute pharyngitis/tonsillitis in a patient testing positive for group-A beta-hemolytic streptococcus in a rapid test, it is necessary to measure the differential white blood cell count, while bearing in mind the possible complication with infectious mononucleosis.
