Bruising following natalizumab infusion for relapsing-remitting multiple sclerosis: a case report

INTRODUCTION: Natalizumab is a new treatment for relapsing-remitting multiple sclerosis. Because of limited experience of this treatment, medical professionals must be alert to possible side effects. CASE PRESENTATION: We present a 34-year-old Caucasian woman with relapsing-remitting multiple sclerosis. She developed bruises on her legs after the first and second administrations of the new monoclonal antibody, natalizumab. Clinical and laboratory investigations revealed no hematological abnormalities. At the time of writing, she has remained on natalizumab treatment without any further side effects. CONCLUSION: In our patient, bruises on the lower extremities may be a benign side effect of natalizumab. This is the first documented incidence of this side effect, and the patient did not require discontinuation of natalizumab treatment.