Most women certainly have their own favourite skin care products. Skincare products are used to make their user look better. There are various types of skincare products, from cleansing soap, moisturisers, to makeup.

However, there are several types of skincare products that can cause allergies. Generally, those allergies are caused by chemicals that are not safe for the face, such as fragrances and sulphates. Those ingredients can cause itching, redness, dry skin, to rashes. Previously, there were no studies that investigated how these compounds trigger allergic reactions on the face. Then, a study published recently in the Science Immunology journal may give the answer.

Basically, allergies occur when the immune system's T-cells find foreign objects in the body and respond to them. In general, chemical compounds that can cause allergies to skincare have a small size, so they should not be detected by T-cells. However, researchers found that these compounds can bind to the CD1a molecule and make them detectable by T-cells.

CD1a molecules are molecules found in Langerhans cells (immune cells in the outer layer of the skin). Chemical compounds can bind to CD1a molecules and activate T-cells. Naturally, CD1a molecules play a role in binding lipids on the surface of the skin to the inside of these molecules. This lipid will be a barrier that can prevent interaction with T-cells. In the case of allergies, chemical compounds present in skincare products can replace the lipids in the CD1a molecule, making it detectable by T-cells.

Text by Anggie Triana
Stock photos from Getty Images

Source(s):

• Nicolai, S., Wegrecki M., Tan-Yun, C., et al (2020). Human T Cell response to CD1a and contact dermatitis allergens in botanical extracts and commercial skin care products. Science Immunology, DOI: 10.1126 / sciimmunol.aax5430.
• Science Daily - Study explains why some creams and cosmetics may cause a skin rash (2020). https://www.sciencedaily.com/releases/2020/01/200103141041.htm, 6 January 2020.