A Nation-wide Increase in the Incidence of Atopic Dermatitis and the Possible Influence of the COVID-19 Pandemic.

BACKGROUND

The association between new-onset atopic dermatitis (AD) and the coronavirus disease 2019 (COVID-19) pandemic was scarcely documented in the literature.

OBJECTIVES

To evaluate the incidence of AD in a large nation-wide cohort over 6 years, focusing on changes in incidence following the onset of the COVID-19 pandemic.

METHODS

This retrospective cohort study included all members of the largest HMO in Israel (n=4.8 million) from 2017 to 2022. Patients with newly diagnosed AD were identified using the ICD-10 code for AD (L20). Incidence rates were calculated as the number of new diagnoses per 1000 person-years. The pre-COVID period was 1/2017 to 1/2020, and post-COVID 2/2020 to 12/2022. Age-adjusted incidence rates were calculated based on the World Health Organization's standard population.

RESULTS

The overall crude incidence of AD across the study period was 3.38/1000 person-years (PYs). From 2017 to 2022, there was a 36.97% increase in the crude incidence and a 40.44% increase in the age-adjusted incidence, with a mean annual incidence change of +6.5% and +7.1%, respectively. Both crude and adjusted annual incidence increases were significant (P < 0.001, R2 = 0.98; P < 0.001, R2 = 0.99, respectively). The incidence of AD at the follow-up before the COVID-19 pandemic was 3.07/1000 PYs, and after was 3.71/1000 PYs.

CONCLUSIONS

We observed a significant and nearly consistent annual increase in AD incidence from 2017 to 2022, across various sex and age groups. Further research is needed to explore the impact of the COVID-19 pandemic on rising trends in AD incidence.