Abemaciclib-Associated Skin, Hair, and Nail Toxicities: A Case Report

Abemaciclib, a CDK4/6 inhibitor used for hormone-sensitive HER2-positive metastatic breast cancer, can cause dermatological side effects, including rash, pruritus, hair loss, nail changes, vitiligo, and photosensitivity, though these are less common. These cutaneous adverse effects contribute to 25% of medication discontinuations. This case report details a patient who developed hair, nail, and pigmentary disorders 10 months after starting abemaciclib treatment.