Recurrent Subcutaneous Sweet's Disease in a Myelofibrosis Patient Treated with Ruxolitinib before Allogeneic Stem Cell Transplantation.

Allogeneic hematopoietic stem cell transplantation (allo-SCT) has a curative potential for myelofibrosis (MF) patients; however, its association with a high therapy-related mortality (TRM) remains a big obstacle that needs to be overcome. Ruxolitinib (RUXO), a novel JAK1/2 inhibitor, can be used as a bridging therapy until allo-SCT can be performed to reduce TRM. We herein report a RUXO-treated MF patient who developed recurrent subcutaneous Sweet's disease (SSD) that was successfully treated by the administration of systemic glucocorticoids. We performed allo-SCT as previously scheduled, resulting in a good clinical course without deterioration of SSD. RUXO administration, as well as MF itself, might therefore sometimes cause this rare non-infectious event.