The treatment of melanoma has long favored the use of immunologic agents. Ipilimumab is a monoclonal antibody used to enhance the immune response. This therapy is associated with a variety of adverse reactions including skin reactions. Although dermatologic toxicities associated with the use of ipilimumab are common, delayed hypersensitivity reactions related to the drug have yet to be identified. This report is believed to be the first case of a delayed, severe dermatologic drug-related reaction secondary to ipilimumab. This case highlights the potential for severe toxicity for long periods after administration of ipilimumab.