International scientist group find how creams, cosmetics cause skin rash

An international team identified how chemical compounds in creams and cosmetics cause rashes in the skin, suggesting a new way to treat the allergic condition.

The study published this week in the journal Science Immunology showed that an abundant molecule on the immune cells in the skin’s outer layer exposes those chemicals to T cells that orchestrate the immune system’s response to foreign chemicals.

Why some chemicals trigger dermatitis was a mystery, since small chemicals have to bind to a larger protein in order to become visible to T cells, but few chemicals do this by undergoing a chemical reaction inside our body.

Researchers at Columbia University, the Brigham and Women’s Hospital, Cardiff University and Monash University found that several common chemicals known to trigger allergic contact dermatitis were able to bind to molecules called CD1a on the surface of skin immune cells and then activate T cells.