Background
During the first wave of the COVID-19 pandemic of Spring 2020, Denmark was one of the first countries to introduce lockdown measures, including closing of all daycare centers. Following the reopening of daycare centers, Danish Health Authorities implemented a mandatory intensive hand hygiene regimen.

Objectives
To examine the occurrence and point prevalence of hand eczema as a consequence of more intensive hand hygiene among Danish children attending daycare.

Methods
The heads of 1667 daycare centers in Denmark were contacted and asked to forward a link to a questionnaire to parents of the children attending the daycare center.

Results
Among 6858 children, 12.1% had hand eczema before reopening of daycare centers, whereas 38.3% reported hand eczema after the children returned to daycare. Of the children who never had hand eczema, 28.6% developed hand eczema after returning to daycare. The risk of hand eczema was significantly associated with atopic dermatitis, female gender, higher age, and frequency of handwashing.

Conclusion
Following the implemented hygiene regimen, a high proportion of young children rapidly developed hand eczema. Well-established prophylactic skin care might have spared a proportion of the children from developing hand eczema.