The discovery of immune checkpoint inhibitors [monoclonal antibodies that target cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), programmed cell death protein 1 (PD-1), or programmed death-ligand 1 (PD-L1)] marked a significant advance in cancer therapy. Immune checkpoint blockade medicines had a highly unique safety profile, despite a positive risk/benefit ratio. Because of their distinct method of action, they caused a novel set of adverse events, the majority of which were immune-related [immune-related adverse events (irAEs)], which were primarily caused by the activation of cytotoxic CD4+/CD8+ T cells. Appropriate therapy and counseling are also recommended, along with a step-by-step strategy for optimal care by both professional oncologists and dermatologists. The clinical and histopathologic characteristics of dermatologic irAEs caused by immune checkpoint inhibitors were discussed by researchers for a review.

Cutaneous toxicities appeared to be one of the most common irAEs, whether with anti-PD-1 and anti-CTLA-4 drugs or the recently introduced anti-PD-L1 medicines, indicating a class effect. They appeared in more than one-third of treated individuals, primarily as a maculopapular rash (eczema-like spongiotic dermatitis) and pruritus. Other dermatologic signs included lichenoid responses, psoriasis, acneiform rashes, vitiligo-like lesions, autoimmune skin illnesses (e.g., bullous pemphigoid, dermatomyositis, alopecia areata), sarcoidosis, and nail and oral mucosal alterations. 

Furthermore, as compared to single treatments, the administration of anti-CTLA-4 and anti-PD-1 therapy in combination was related to the development of more frequent, more severe, and earlier cutaneous irAEs. In the majority of instances, these days immune dermatologic adverse effects were self-limiting and easily managed. Early detection and management, on the other hand, were crucial to avoiding worsening of the lesions, limiting treatment interruption, and minimizing the quality of life damage.