Case Report of Probable DRESS Syndrome Associated with Ribociclib.

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare but known and potentially severe side effect of drugs. The recent development of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors, such as ribociclib, has considerably improved the management of hormone receptor positive (HR+) and HER2 negative (HER2-) advanced breast cancer. Here, we present the case of an 83-year-old patient who developed a probable DRESS syndrome induced by ribociclib, presenting with fever, eosinophilia, rash, and hepatic cytolysis.