People being treated for acne often need to change some of the cosmetics they use. All cosmetics, such as foundation, blush, eye shadow, and moisturizers, should be oil free. Patients may find it difficult to apply foundation evenly during the first few weeks of treatment because skin may be red or scaly, particularly with the use of topical tretinoin or benzoyl peroxide. Lip products that contain moisturizers may cause small, open and closed comedones to form. Hairstyling products that come in contact with the skin along the hairline can cause burning or stinging in people with acne. Products that are labeled as noncomedogenic (do not promote the formation of blemishes) should be used; in some people, however, even these products may cause acne.