CTLA4 and Erythema: Dermatological❖ Most common manifestation and earliest to occur.❖ Seen in 2–3 weeks after initiation of treatment with ipilimumab.❖ Commonly seen after the first dose.❖ Manifests as maculopapular rash, erythema, pruritus, dry skin, alopecia or hypertrichosis, lichenoid keratosis and vitiligo. More common with CTLA-4 inhibitors. Seen in up to 47–68% patient on anti-CTLA-4 therapy and 30–40% patients on anti-PD-1/anti-PD-L1 therapy. Mucositis and vitiligo are more common in patients receiving anti-PD-1/anti-PD-L1 agents