Cutaneous T-cell lymphoma (CTCL) represents a diagnostic challenge because of its large symptomatic overlap with other common skin conditions such as atopic dermatitis (AD) and psoriasis. Dupilumab has offered promising results in AD treatment; however, concerns exist that its use may exacerbate undiagnosed CTCL. We present a patient with CTCL and concomitant AD who experienced improvement in both CTCL blood involvement and AD following the addition of dupilumab therapy.