Cutaneous Side Effects of Modern Targeted Therapy and Immunotherapy in Patients with Dermatological Malignancies

The document discusses the cutaneous side effects of modern dermato-oncological therapies, including immune checkpoint inhibitors and targeted therapies. These treatments have improved the management of dermatological malignancies but can cause skin toxicity, affecting treatment continuation and patient quality of life. Common side effects include maculopapular rash, lichenoid rash, and psoriasiform rash. Autoimmune bullous disorders are prevalent in 1-8% of patients receiving immune checkpoint inhibitors, particularly PD-1/PD-L1 inhibitors. Pruritus and vitiligo are also common, with vitiligo incidence being approximately 11% and 25% with CTLA-4 & PD-1/PDL1 inhibitors, respectively. Hair disorders, particularly alopecia areata, are common among melanoma patients receiving these inhibitors, with onset usually 3-6 months after treatment initiation. Other hair toxicities include cases of telogen effluvium. MEK-Inhibitors often cause a papulopustular eruption, with an incidence between 40% and 93%, and other cutaneous side effects like pruritus, xerosis, and hair disorders. Hedgehog-Inhibitors can cause alopecia with a prevalence as high as 63%, with hair regrowth taking approximately 6–12 months after therapy discontinuation. Severe cutaneous drug reactions, such as Stevens–Johnson syndrome, toxic epidermal necrolysis, AGEP, and DRESS, have been scarcely reported to occur under treatment with ICIs.