Panniculitis is an uncommon reaction that may occur secondary to cytotoxic chemotherapy, immune checkpoint inhibitors, or small molecule inhibitors. It has been reported to occur in 2.5% to 11% of patients on the BRAF inhibitors dabrafenib and vemurafenib, respectively.¹ For most tyrosine kinase inhibitors, it is more likely to occur secondary to newer generation agents.² Presentations can vary, ranging from firm erythematous subcutaneous nodules to necrotizing, erythematous ulcers typically occurring on the extremities (Figures 9.1,9.2,9.3).³,⁴,⁵ Cutaneous findings can be associated with systemic symptoms such as fevers or arthralgias.⁵ Females are more commonly affected than males.⁵