We reviewed all MS patients treated with Fingolimod at our MS center between October 2011 and May 2018 and identified patients who developed skin warts during treatment. We also reviewed a similar cohort of patients treated with different Interferons matched for age and sex as a control group.

Of a total of 220 patients treated with Fingolimod at our MS center, five developed skin warts, however, in 220 patients treated with different Interferons and matched for age and sex, no cases of skin warts could be detected. Two of these patients  developed genital warts due to the human papilloma virus (HPV), one patient developed nasal mucosal warts, and two other patients developed feet warts.

In conclusion, we describe the first reported case series of skin warts on Fingolimod treatment. We identified five patients who developed skin warts during treatment for an overall incidence of 2.2%.These reported cases shed light on a potentially increased incidence of warts infections and particularly HPV-related warts in Fingolimod-treated patients. Larger cohorts are needed to confirm this proposed higher susceptibility of Fingolimod-treated patients to HPV infections.