Scientists May Have Discovered a New Way to Treat Contact Dermatitis

Our immune systems are extremely important. They help us to identify and fight foreign invaders such as viruses. However, allergies occur when our immune systems are triggered and respond to harmless substances such as nuts or pollen. 

Contact dermatitis is a skin condition which is characterised by an itchy rash. Urushiol (yoo-ROO-shee-all), a chemical present in poison Ivy, is able to trigger allergic contact dermatitis in the majority of individuals. However, researchers have now identified other chemicals, present in cosmetics and creams, which are also able to trigger contact dermatitis in a subset of the population.

T cells are the cells responsible for our immune system’s response to foreign substances. However, scientists have long known that these T cells are unable to directly identify small molecules. So how do these small molecules result in allergic reactions? Well, what scientists now know is that some of these small molecules are able to bind to larger proteins, found on the surface of certain cells present in the skin’s outer layer. Once bound to these larger proteins, it makes them visible to the T cells. 

The researchers, from Columbia University Irving Medical Center, tested a variety of chemicals that are known triggers of contact dermatitis. They subsequently confirmed that these chemicals did bind to the larger proteins, allowing them to be identified by the T cells to result in an immune response. However, it is important to note that their work has only been carried out in human tissue cells. Therefore, although it is promising, we cannot yet conclude that the exact same reactions occur in allergic patients.

This new knowledge has now inspired unique ideas for treating contact dermatitis. If we can stop the offending chemicals, found in creams and fragrances, from binding to the large proteins, then the T cells will not recognise them and there will be no immune response to trigger contact dermatitis. Scientists are hoping to achieve this by getting the large proteins to bind to other substances instead, such as fat-like molecules, that do not result in immune reactions. Previously, the only way to prevent contact dermatitis was to stop using the offending chemicals, so this approach is definitely very exciting.