Atopic Dermatitis and Dementia Risk: A Nationwide Longitudinal Study

Background Retrospective studies have suggested that patients with dementia have higher atopic dermatitis (AD) prevalence than do those without dementia. Objective However, the temporal association of AD with subsequent dementia remains unknown. Methods We included data of patients with AD aged ≥45 years (n = 1,059) and 1:10 age, sex, residence, income, and dementia-related comorbidity–matched controls (n =10,590) from the Taiwan National Health Insurance Research Database and reviewed their subsequent dementia development from the enrollment date to the end of 2013. Results After adjustments for dementia-related comorbidities, patients with AD were found to be more likely to develop any dementia (hazard ratio [HR]: 2.02, 95% confidence interval [CI]: 1.24–3.29), particularly Alzheimer's disease (HR: 3.74, 95% CI: 1.17–11.97), during the follow-up period than were those in the control group. Moderate-to-severe AD was associated with a high subsequent dementia risk (HR: 4.64, 95% CI: 2.58–8.33). Sensitivity analyses with the exclusion of the first 3 (HR: 2.20, 95% CI: 1.28–3.80) or 5 (HR: 2.05, 95% CI: 1.08–3.89) years of observation showed consistent findings. Conclusion AD may be an independent risk factor for new-onset dementia. Clinicians may monitor the trajectory of neurocognitive function among elderly patients with AD. Additional studies elucidating the pathomechanisms between AD and subsequent dementia are warranted.