Nivolumab-associated extragenital lichen sclerosus et atrophicus

Recently the first case of genital lichen sclerosus (LS) involving the vulval, perineal and perianal areas during treatment with Nivolumab was published1 . Nivolumab is a human monoclonal antibody, approved by the US Food and Drug Administration (FDA) in December 2014 for the treatment of metastatic melanoma (MM)2 . It works by inhibiting the interaction between programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1), whose unimpeded interaction downregulates T cells allowing cancer cells to evade immune surveillance.