Skin rash in a patient with infectious mononucleosis.

To cite: Kenzaka T, Ueda Y. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/ bcr-2013-010236 DESCRIPTION A 24-year-old woman with no notable medical history visited a clinic because of fever, sore throat and posterior cervical adenopathy since 3 days. Her body temperature was 38°C. Ampicillin was prescribed for sore throat and adenopathy. Four days later, she developed arthralgia, eyelid oedema and rash all over her body, except on her eyelids, and was referred to our hospital. Physical examination revealed a temperature of 38°C, blood pressure of 102/60 mm Hg and a regular pulse rate of 92 bpm; further, her anterior and posterior cervical lymph nodes were palpable. The systemic rash was clearly defined, maculopapular and pruritic in nature, and was accompanied with slight fever (figures 1 and 2). In addition, mild splenomegaly was observed. Blood tests showed liver dysfunction and atypical lymphocytes. Results of blood testing conducted during the initial visit revealed a pattern of prior infection with measles and rubella. Results of tests for Epstein-Barr virus (EBV)-vascularised composite allografts (VCA) IgM and IgG were positive, whereas that for Epstein-Barr nuclear antigen (EBNA) was negative. The paired serum was positive for EBNA; thus, diagnoses of infectious mononucleosis caused by EBV primary infection and skin rash caused by ampicillin were made. The skin rash began to disappear by about 1 week, and it improved in over about 3 months. Administration of ampicillin to a patient with infectious mononucleosis caused by EBV primary infection should be avoided. If ampicillin is administered, the patient has a high probability of developing a skin rash several days after the administration. 2