Herpes zoster laryngitis in a patient treated with fingolimod

Development of treatment with immunomodulatory agents has improved prognosis of various autoimmune-related diseases. A sphingosin-1-phosphate receptor modulator, or fingolimod, is the first licensed oral drug for relapsing-remitting multiple sclerosis. The agent reduces circulating lymphocytes by trapping T cells in lymph nodes, possibly leading to reactivation of latent viruses. A 41-year-old Japanese woman who had been treated with fingolimod for 2 years presented with unilateral sore throat. Laryngoscopy revealed exudates unilaterally emerging on the left side of her supraglottic region. Serum level of the varicella zoster virus (VZV)-specific IgG was markedly elevated, and a result of genome sequence using the exudates demonstrated VZV as a possible causative pathogen. Fingolimod therapy was discontinued and the patient was successfully treated with intravenous acyclovir. This is the first reported case of fingolimod-associated herpes zoster laryngitis, in which the local VZV reactivation was demonstrated by next-generation sequencing technology. The present case highlights that the occurrence of VZV reactivation should be recalled in any patients undergoing fingolimod therapy.