Dupilumab is a monoclonal antibody that inhibits interleukin-4 and interleukin-13 signaling. It is the first biologic agent to demonstrate efficacy in treating moderate-to-severe refractory atopic dermatitis [1, 2]. Although dupilumab provides promise for the treatment of atopic and allergic conditions, clinicians should take into account its novelty and the potential for unexpected adverse events. We present a patient who developed Sézary syndrome following the initiation of dupilumab
