New treatments for eczema could be developed following research carried out at the University of Edinburgh.
Scientists there have found exposure to sunlight releases a compound in the skin which can alleviate symptoms.
The nitric oxide molecule dampens inflammation, which causes itchy skin associated with the condition.
The researchers hope new treatments which mimic the effects of the sun could help replace light therapy, which can damage the skin.
Lead researcher Dr Anne Astier said: "Our findings suggest that nitric oxide has powerful anti-inflammatory properties and could offer an alternative drug target for people with eczema."
Researchers exposed healthy volunteers to UV light, on a small patch of skin, and found nitric oxide was released into the bloodstream.
The chemical activates specialised immune cells called regulatory T cells which dampen down inflammation.
Prof Richard Weller, senior lecturer in dermatology at the University of Edinburgh, said: "It is clear that the health benefits of sunlight stretch far beyond vitamin D and we are starting to fill in these blank spaces."
The research is published in the Journal of Allergy and Clinical Immunology.