LAUSR

To the Editor: Although immune checkpoint inhibitors (ICIs) were originally used for metastatic melanoma, their efficacy has popularized their use in nonmelanomamalignancies. Immune checkpoint inhibitors include anti–cytotoxic T-lymphocyte–associated protein 4 (eg, ipilimumab, tremelimumab) and anti–programmed cell death protein 1/ligand 1 (eg, pembrolizumab, nivolumab, cemiplimab, durvalumab), drugs that reinstate the endogenous antitumor response by inhibiting negative regulators of immune activation such as cytotoxic T-lymphocyte–associated protein 4 and programmed cell death protein 1/ligand 1. This mechanism is thought to activate cytotoxic CD4/CD8 T cells and trigger immune-mediated toxicities against healthy tissues. Cutaneous adverse events are the most common ICI-induced toxicities across all tumor types (all-grade incidence of 24.28% with nivolumab, 50.56% with nivolumab-ipilimumab combination) with a median onset time of 2 months. The ICI-induced vitiligo in melanoma patients is often untreated because of the fair-skinned predominance in melanoma patients and the risk for iatrogenic skin cancer with ultraviolet (UV) phototherapy. Literature on the longstanding stability of the depigmentation and its use as a prognostic marker for ICI-treated melanoma patients has further discouraged aggressive treatment. However, with the broadening indications for ICI use beyond melanoma, patient demographic includes more skin-of-color (SOC) patients reporting rapid depigmentation. Studies with SOC patients show that this supposedly asymptomatic disease can in fact provoke depression, isolation, and thoughts of harming oneself. This prompts the presumed irreversibility of ICI-induced vitiligo to be reconsidered. We present the case of a 56-year-old Hispanic man with Fitzpatrick skin type III who developed vitiligo after ICI treatment for metastatic renal cell cancer. After a right nephrectomy in April 2018, the patient received nivolumab 240mg and ipilimumab 90mg every 3 weeks for 2 cycles. Patient transitioned to nivolumab 240 mg every 4 weeks until May 2019, at which point imaging showed complete remission of the renal cell carcinoma, and nivolumab use was suspended. Two months after cessation and 12 months after starting ICI therapy, the patient presented with depigmented macules coalescing into patches on hands, underarms, and abdomen. He denied previous personal or family autoimmune or cutaneous disease history.