Beauty products -- everything from shampoo to makeup to cologne -- can help you feel on top of your game. They can also cause irritated skin or an allergic reaction. A dermatology study published in 2010 found that more than a third of over 900 study participants had at least one allergic reaction to cosmetic ingredients. 

Problems can range from simple rashes to full-blown allergic reactions. Symptoms can start right after you use something new -- or after years of using a product with no problems.

From WebMD