A Case of Diphtheria and Infectious Mononucleosis Co-Infection in a Partially Vaccinated Boy

We report the case of an eight-year-old partially immunized boy who presented with presumed bacterial tonsillitis. He was initially prescribed amoxicillin-clavulanic acid which resulted in the development of an erythematous maculopapular over the face which spread to the trunk and extremities including palms and soles and resolved over the next three days. He was diagnosed to have diphtheria and infectious mononucleosis (IMN) co-infection. He made an uneventful recovery and an extensive review of the literature showed that the incidence of diphtheria and IMN co-infection is a relatively rare clinical entity. We wish to highlight the possibility of such co-infections which often mimic one another.