People with celiac disease may unknowingly be exposed to gluten in lip, facial and body products. Gluten is a protein found in wheat, rye and barley, and damages the intestines of people with celiac disease. This is quite alarming because gluten-containing cosmetics can be inadvertently used by gluten sensitive people, resulting in gastrointestinal issues and skin rashes, especially in products marked as natural. Celiac patients need to check the ingredient list of their skin care products very carefully. The problem is that many companies don't bother listing them. (American College of Gastroenterology, Oct 28th 2011)

Doing some research for a family member and saw this - this is the first time I was aware of this