Compounds in the products pass 'under the radar' in standard safety tests, but they are still being seen by the body's immune system because of a complex chemical reaction that happens when they are put on the skin.
Chemicals in the products cause a reaction that make them visible to our immune system's T cells—and it's this process that causes the rash.
Essentially, the chemicals are displacing our natural fat-like molecules, called lipids.
Compounds that are most likely to cause a skin rash are Balsam of Peru and farnesol, which are both found in many skincare products, say researchers from Columbia University Irving Medical Centre.
Benzyl benzoate and benzyl cinnamate are the main active ingredients in Balsam of Peru that cause the reaction, although the researchers discovered 12 that could also be responsible.
The only solution is to stop using the cosmetics, while topical ointments can help soothe the rash, and severe cases may have to be treated with oral corticosteroids, the researchers say—but they are also looking at ways of developing an ointment that applies other lipids to the skin first, thus blocking the process from the start.
The Get Well Show
If you are keen to learn more on some of the conditions mentioned in this topic, the Get Well Show is your chance to hear from some of the leading minds in alternative medicine.
Dr. Kim A. Jobst will be discussing 'What if Disease is A Manifestation of Health?' on Friday, February 21st.