specimen. Her MF was staged as IIB, CD4 folliculotropic with large cell transformation.Mycosis fungoides can be difficult to distinguish from AD, especially adult-onset/recurrent AD that is reported in 1 of 4 adults with AD. 2 Accurate diagnosis of MF is critical as delayed treatment may be detrimental. In retrospect, this patient likely had MF before starting dupilumab, although the diagnosis was not confirmed earlier because of limitations of available diagnostic testing.Cutaneous T-cell lymphoma was reported after dupilumab treatment for presumed AD. 3,4 Dupilumab induced a flare-up of cutaneous lesions in a patient with presumed AD, leading to consideration of MF. 3 One case reported large cell transformation of MF after dupilumab treatment. 4 Antigenic immunostimulation may result in malignant lymphocyte clonality in chronic dermatitis, thereby precipitating CTCL. 5 Mycosis fungoides is characterized by interleukin 2 (IL-2), IL-7, and IL-15 signaling in early disease, as well as T H 2 responses in later disease. Selective inhibition of T H 2 responses by dupilumab may immunostimulate T H 1 or other cytokines and worsen MF. Although dupilumab may initially alleviate pruritus, we advise caution about using dupilumab to treat patients with CTCL even in a patient with a history of AD. Furthermore, patients who fail methotrexate and other advanced AD treatments should receive further workup for diagnosis confirmation. Finally, long-term monitoring of dupilumab response is warranted even in patients with initial improvement.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.