The prevalence of atopic dermatitis has increased along with urbanization and biodiversity loss. According to biodiversity hypothesis, the main reason is urban lifestyle and reduced contact to microbial diversity. Previous studies indicate association between atopic dermatitis and exposure to natural microbes in childhood.

Sand Play - the Effect of Biodiversity Exposure on Atopic Dermatitis will investigate whether the exposure to microbial diversity in sandbox reduces the symptoms of atopic dermatitis, alters commensal microbiota and modifies immune regulation in children.

Our specific aims are:

To assess if exposure to microbial diversity reduces Eczema Area and Severity Index (EASI) and Patient-Oriented Eczema Measure (POEM).

Assess whether the sand play alters plasma cytokine profiles, white blood cell distributions, allergy specific IgE, and commensal microbial communities on skin, in saliva and gut.

The investigators will recruit approximately 80 (40 study subjects per treatment) subjects with atopic dermatitis and aged between 2-5.

Inclusion Criteria:

• Eczema Area and Severity Index ≥ 2

Exclusion Criteria:

• Eczema Area and Severity Index < 2
• Immune deficiencies, i.e., antibody deficiency
• Immunosuppressive systematic medications
• A disease affecting immune response (e.g., colitis ulcerosa, rheumatoid arthritis, Crohn's disease, diabetes)
• Cancer diagnosis
• Topical medication for the treatment of atopic dermatitis during the trial
• Disability affecting the immune response (e.g. Down's syndrome)
• Non-participation in the national vaccine program
• Participation in another intervention or follow-up study