Atopic eczema, a chronic inflammatory illness that has lately been identified as being widespread in older persons, has not been well studied in relation to dementia. For a study, researchers sought to determine if incident dementia and active atopic eczema were related.

The longitudinal cohort research included 1,767,667 people from The Health Improvement Network, a primary care cohort in the UK, aged 60 to 99. Medical record codes were used to identify dementia and atopic eczema diagnosis.

During follow-up, persons with atopic eczema (12.1% of the population) had a dementia incidence of 57 per 10,000 person-years compared to 44 per 10,000 person-years in the control group. In adjusted Cox proportional hazard models, this resulted in a 27% higher risk of dementia (hazard ratio, 1.27; 95% CI, 1.23-1.30). Similar relationships were found in subgroup studies of vascular dementia and Alzheimer’s disease. After further controlling for systemic corticosteroids and possible mediators, the link remained (hazard ratio, 1.29; 95% Cl, 1.26–1.33) and potential mediators (hazard ratio, 1.19; 95% CI, 1.16-1.22). The risk of dementia increases with the severity of eczema.

There was a slight but elevated incidence of incident dementia in those with atopic eczema. Moreover, the association got stronger as atopic eczema got worse.