A case of trichodysplasia spinulosa related to ruxolitinib treated successfully with oral acitretin

Trichodysplasia spinulosa (TS) is a rare disease that affects immunocompromised patients, characterized by hair‐like growths caused by TS‐associated polyomavirus infection. Little is known about specific immunosuppressive drugs that can precipitate the condition. We report a case of TS presenting after initiating the oral Janus‐associated kinase inhibitor (JAKi) ruxolitinib. A 67‐year‐old female with a history of allogeneic bone marrow transplant requiring immunosuppression with tacrolimus, prednisone and, more recently, ruxolitinib 5 mg twice daily due to Graft versus Host Disease presented to the clinic with a facial rash. The clinical and histopathological findings in the setting of immunosuppression were consistent with TS. Initial treatments were ineffective, but oral acitretin showed significant improvement after 3 months. Due to the close temporal relationship between the initiation of ruxolitinib and the development of TS, this case suggests that JAKis may contribute to TS development by suppressing the JAK‐signal transducer and activator of the transcription pathway's antiviral functions.