Polydermatomal perineal and gluteal herpes zoster infection in a patient on fingolimod treatment.

Fingolimod is a new oral administrated sphingosine 1phosphate receptor modulator, approved for treatment of multiple sclerosis (MS) patients.1,2 There is evidence that fingolimod acts by preventing lymphocyte egress from lymph nodes, spleen and thymus by antagonistic action on the sphingosine 1-phosphate receptors. These receptors regulate proliferation, differentiation, survival, chemotaxis and diapedesis.3,4 Although an increase in opportunistic infections has not been documented in clinical trials,1,2 current experience suggests that fingolimod might increase the risk of severe herpetic infections. Fatal cases of herpetic infections have occurred in two patients on fingolimod.5 Recently, a case of varicella zoster encephalitis and vasculopathy has been reported in a VZV seropositive patient receiving fingolimod.6 Usually authors discontinue the novel therapy indefinitely and switch to another disease modulating drug. In all reported cases there was diminished lymphocytes blood count on admission laboratory tests.6–8 We present a case of polydermatomal zoster with genital involvement occurring in a MS patient four months after the initiation of fingolimod therapy.