Dermatologic autoimmunity associated with immune checkpoint inhibitors

Through a better understanding of cancer’s biology, the systemic treatment of cancer has changed significantly in the past decades by the development of immunotherapies. The most dramatic changes in patient outcome are the result of immune checkpoint inhibitors (ICI), which are currently indicated for the first- and second-line treatment of an increasing range of cancers. ICIs restore the antitumor response by modulating the regulatory pathways of the immune system; however, the desirable antitumor response can also generate undesirable immune-related adverse events (irAEs). The most affected organ is the skin, with dermatologic irAEs appearing in more than one-third of the patients. While the precise mechanisms of these irAEs are not fully understood, the inhibition of immune checkpoints and therefore the disturbance of immunologic tolerance seems to be the most likely mechanism. In this chapter, we will discuss the most common and specific dermatologic irAEs associated with ICI.