RÉSUMÉ
During the course of infectious mononucleosis, intake of ampicillin and its analogues such as amoxicillin may cause hypersensitivity skin rashes. We report herein a case of ampicillin induced skin rash in a 41-year-old female patient with infectious mononucleosis. Infectious mononucleosis was confirrned by datetion of IgM antibody against Epstein-Barr(EB) viral capsid antigen(VCA) in her serum. During the icuteillness, she taked ampicillin for 3 days, and 1 week after the intake of ampicillin, a genertliz:d erythernatous and purpuric maculopapualr eruption developed. Physicians should be careful not to use ampicillin and its analogue if batients are suspected to be infected with EB virus as ampicillin induces severe skin rashes in patients with infectious mononucleosis.