LAUSR

An important distinction between vascularized composite allotransplantation (VCA) and solid organ transplantation is exposure of the transplant to the external environment. The implications of seasonal climate variations and environmental exposure on the outcome of VCA are unknown. Here, we report on a case of recurring wintertime rejection and its subsequent management with seasonal prophylactic increased immunosuppression. Our patient underwent successful bilateral upper extremity transplantation in 2011 after amputation secondary to urosepsis 9 years previously. After transplantation (HLA 5/6 mismatch), our patient presented during 2 consecutive winters with episodes of periungual erythema and desquamation concerning for acute rejection, despite consistent adherence to standard maintenance immunosuppression (mycophenolate mofetil, 360 mg BID and oral tacrolimus, 2-4 mg BID) and stable serum tacrolimus levels within the target range. During both occasions, histopathological examination of allograft skin biopsies revealed prominent perivascular lymphoid infiltrates and dyskeratosis consistent with Banff grade 2 to 3 rejection. Both episodes resolved completely with in-