Long-standing Dermatitis Treated With Dupilumab With Subsequent Progression to Cutaneous T-cell Lymphoma

This case series discusses 3 patients with long-standing eczematous or psoriasiform dermatitis, demonstrated by multiple biopsies.Following off-label treatment with dupilumab, all 3 patients had clinical expansion of disease, with histopathologic features consistent with cutaneous T-cell lymphoma (CTCL) on subsequent biopsy.We postulate that this expansion likely was secondary to an exacerbation of extant CTCL following exposure to dupilumab.A proposed mechanism of promotion of CTCL is based on the functional increase in IL-13 available for binding at the upregulated IL-13 receptor (IL-13R) α2 site on cells, following blockade of the α1 receptor with dupilumab.This progression merits further investigation.