Bare Escentuals, or Bare Minerals makeup has been advertised for years as being so natural and pure, you can sleep in it without any concerns. Manufacturers of the products tout its high quality ingredients, lack of fragrances, chemicals or skin irritants, and feather-light application, which allegedly makes the makeup ideal for all skin types. However, there have been numerous consumer complaints about side effects and allergic reactions to the products. If you have sensitive skin, use caution if you're first trying any of their products.

Bare Escentuals advertises that it uses only the finest crushed minerals in their products that are 100 percent pure. Minerals such as titanium dioxide, zinc oxide, bismuth oxychloride, mica and iron oxide are prominent on the labels. Titanium oxide is a colorant used in many skin care lines that thickens and whitens the product. It provides some protection from the sun's UVA and UVB rays. Zinc oxide is also a sunscreen that provides moisture resistance. Zinc calms the skin and helps reduce irritation. Mica provides radiance to skin tone and iron oxide provides colorant to the foundation products. Bismuth oxychloride creates a pearlescent glow to the skin and is known to cause problems for some women.

Bismuth oxychloride may cause a variety of allergic reactions in some Bare Escentual users. It can cause itching, swelling, oily skin and rashes, after even a single use. Bismuth might also create heat sensitivity in your skin, causing red discoloration and swelling when the makeup mixes with sweat when you become warm.

Some users have reported redness and irritation, including extreme dryness of the skin accompanied by the appearance of additional wrinkles, peeling and itching. The Bare Escentuals powder is especially known for causing these reactions, as is the facial mask.

Users have reported blemishes and breakouts, including pimples, after using one or more of the Bare Escentuals products -- specifically, their foundation. This is blamed on the presence of bismuth oxychloride, which irritates sensitive skin, as well as the skin of some women who have never before had reactions to makeup. Although the products are known to hide certain cases of rosacea, flare-ups are reported in cases where the individual’s sweat mixes with the mineral makeup.

There have been reports of swelling, especially of the eyelids and around the mouth, after using several of the Bare Escentuals products, such as the Mineral Veil. Swelling is a sign of both irritation and allergy. In certain cases, users were forced to visit dermatologists and use steroid creams to help reduce swelling, rawness and excessive redness of the skin.

Although Bare Escentuals claims to use only the finest ingredients in their products, it's evident that some women have serious allergic reactions to those ingredients. If you use any of the products and experience unpleasant skin reactions, stop using them immediately. If the reaction lingers without improvement for more than 24 hours, consult your dermatologist. Use care when choosing a new makeup line, especially if you have allergies or sensitive skin.