Background: Dupilumab has revolutionized treatment of moderate-to-severe atopic dermatitis (AD). However, its use has been associated with ophthalmologic adverse events referred to as dupilumab-associated ocular surface disease (DAOSD), reported in up to 30% of patients. Although several risk factors have been proposed, the role of Demodex folliculorum remains poorly defined.

Objectives: To evaluate the association between eyelid Demodex infestation and DAOSD development during the first 16 weeks of dupilumab therapy.

Methods: This prospective study enrolled 30 adults with moderate-to-severe AD initiating dupilumab. All patients underwent ophthalmologic evaluation, Ocular Surface Disease Index (OSDI) scoring, Schirmer testing, conjunctival cultures, and Demodex detection. Follow-up was performed at 16 weeks. Patients were stratified by DAOSD status.

Results: DAOSD developed in 33% (n = 10), presenting as blepharoconjunctivitis. Baseline Demodex infestation was significantly more frequent in the DAOSD group (70.0% vs. 5.0%; p = .0004; OR = 44.3). Baseline Eczema Area and Severity Index (EASI) scores, IgE levels, and Schirmer results did not differ. Post-treatment OSDI scores were higher in DAOSD patients (median 37.5 vs. 4.6; p = .0001). Bacterial cultures were not associated with DAOSD.

Conclusions: Eyelid Demodex infestation is strongly associated with DAOSD development. Pretreatment screening may identify high-risk individuals. As most cases occur within 16 weeks, this study focused on the early treatment phase.