BACKGROUND:

Epidemiological investigations have examined the association between type 1 diabetes mellitus (T1DM) and atopic disease, but have obtained conflicting results.

OBJECTIVES:

To analyse the association between T1DM and atopic dermatitis (AD) in a population-based, retrospective cohort studythat investigated the hypothesis that childhood T1DM is a risk factor for subsequent AD.

METHODS:

From claims data of the National Health Insurance programme of Taiwan, we identified 3386 patients with T1DM newly diagnosed from 1998 to 2011 and 12 725 randomly selected controls without T1DM. These were frequency matched by age, sex and year of diagnosis. Both cohorts were followed up until the end of 2011 to evaluate the AD risk. We used Cox proportional hazards regression models to analyse the risk of AD.

RESULTS:

The overall incidence rate of AD was 1·40-fold (significantly) higher in the T1DM cohort than in the non-T1DM cohort (3·31 vs. 2·35 per 1000 person years). After adjustment for potential risk factors, the overall risk of AD remained higher in the T1DM cohort [adjusted hazard ratio (HR) 1·76, 95% confidence interval (CI) 1·29-2·39] than in those without T1DM. Compared with the non-T1DM cohort, the patients with T1DM with more emergency room visits (adjusted HR 30·1, 95% CI 18·7-48·5) or hospitalizations (adjusted HR 70·3, 95% CI 45·6-114·5) had a higher risk of subsequent AD.

CONCLUSIONS:

This nationwide, retrospective cohort study demonstrates that childhood T1DM may increase the risk of AD.