Paradoxical reaction under dupilumab triggered by occasional ketoprofen intake

Dupilumab, a monoclonal antibody targeting the IL-4/13 signaling pathway, effectively treats moderate-to-severe atopic dermatitis (AD). Common side effects include injection site reactions, conjunctivitis, and respiratory infections. We report the case of a 28-year-old woman with severe AD involving the periocular and chin regions, genital areas, arms, and legs (Eczema Area and Severity Index [EASI]: 24, itch Visual Analog Scale [VAS]: 8) who showed significant improvement after initiating dupilumab therapy. However, following ketoprofen intake for headache relief, she developed a lupus-like erythematous maculopapular rash on the periocular and malar regions. Immunological tests (ANA, ENA) and photopatch testing ruled out autoimmune or allergic causes. Dupilumab was stopped, and treatment with oral prednisone and cetirizine led to complete resolution. This case highlights a potential drug interaction between dupilumab and ketoprofen, emphasizing the need for awareness of paradoxical facial erythema reactions in patients undergoing dupilumab therapy.