One of the best things to have happened to the beauty industry is luxurious skin lotions. Bustling with nourishing butters, they not only hydrate the skin but can also make you smell divine. This makes them the perfect products for winters. Until and unless, of course, you’re a part of the ever-growing band of people who experience skin allergies after lathering on such products.
While we know what to do when skin allergies crop up after using skincare products—anti-histamines for the win, y’all!—but why they happen in the first place is still a big fat mystery for us unsuspecting consumers.
Thankfully, researchers have uncovered the mechanism by which chemicals present in products like lotions and perfumes trigger skin allergy.
According to the study, published in the journal Science Immunology, skin allergies might be triggered by chemicals in consumer products due to the way they displace natural fat-like molecules—called lipids—in skin cells.
The researchers, including those from Columbia University in the US, said an allergic reaction begins when the immune system’s T cells recognise a chemical as foreign. But they added that the T cells do not directly recognise small chemicals since these compounds need to undergo a modification 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,” said study co-author Annemieke de Jong from Columbia University.
“These small chemicals should be invisible to T cells, but they’re not,” de Jong added.
The scientists suspected that CD1a—a molecule found in abundance on the immune cells in the skin’s outer layer called Langerhans cells—may be responsible for making the chemicals visible to T cells.
In the current study, the researchers found that the chemicals known to trigger allergic contact dermatitis (ACD) were able to bind to CD1a molecules on the surface of Langerhans cells and activate T cells.
Chemicals like balsam of Peru, and farnesol, which are found in many personal care products, such as creams, toothpaste, and fragrances, were found to trigger ACD through this mechanism. The researchers identified the chemicals benzyl benzoate and benzyl cinnamate present in balsam of Peru as the causative agents for the reaction, and overall they found more than a dozen small chemicals which activated T cells through CD1a.
“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 added.
While this might be too much science for most of us to comprehend, this research is important because it help scientists to develop more effective ways to treat dermatitis and other types of skin allergies—thus offering the much-needed relief that we need.