Ipilimumab may increase the severity of cutenaous toxicity related to radiotherapy.

Ipilimumab, monoclonal antibody against cytotoxic T-lymphocyte antigen-4 and, radiotherapy are commonly used to treat unresectable and metastatic melanoma. As a result of upregulation of immune system with ipilimumab, many immune-related adverse effects, such as dermatitis, colitis, hepatitis, and hypophysitis, have been previously reported in literature. Typically, these effects are treated with high-dose steroids and mostly heal up. Here, we report a case who was receiving radiotherapy due to metastatic malignant melanoma with atypical generalized rash, which was enlarged with concurrent ipilimumab treatment.