A new study has suggested that the way some chemicals displace natural fat-like molecules in skin cells may explain how many common ingredients trigger allergic contact dermatitis.

 

The study also suggests a new way to treat the condition. The authors noted that allergic reactions in the skin could be caused by different chemical compounds found in creams, cosmetics, and other topical consumer products.

 

According to newsmedical.net, the study, led by researchers from

 

Columbia University Irving Medical Center, the Brigham and Women’s Hospital, as well as Monash University, was published online in the Science Immunology.

 

The study co-leader, Dr Annemieke De Jong, said, “An allergic reaction begins when the immune system’s T cells recognise a chemical as foreign. T cells do not directly recognise small chemicals, and research suggests that these compounds need to undergo a chemical reaction with larger proteins to make themselves visible to T cells.

 

“However, many small compounds in skincare products that trigger allergic contact dermatitis lack the chemical groups needed for this reaction to occur. These small chemicals should be invisible to T cells, but they’re not.”

 

De Jong and her colleagues suspected that CD1A, a molecule that is abundant on Langerhans cells (immune cells in the skin’s outer layer), might be responsible for making these chemicals visible to T cells.

 

In the study conducted with human cells in tissue culture, the researchers found that several common chemicals known to trigger allergic contact dermatitis were able to bind to CD1A molecules on the surface of Langerhans cells and activate T cells.

 

“Our work shows how these chemicals can activate T cells in tissue culture, but we have to be cautious about claiming that this is definitively how it works in allergic patients.

 

“The study does pave the way for follow up studies to confirm the mechanism in allergic patients and design inhibitors of the response,” De Jong said.