Moisturizer, or emollient, is a cosmetic preparation used for protecting, moisturizing, and lubricating the skin.
These functions are normally performed by sebum produced by healthy skin. The word “emollient” is derived from the Latin verb mollire, to soften. Other popular moisturizers are cetyl alcohol, cetearyl alcohol, cocoa butter, isopropyl myristate, isopropyl palmitate, lanolin, liquid paraffin, polyethylene glycols, shea butter, silicone oils, stearic acid, stearyl alcohol and castor oil, as well as other oils.
Moisturizers are used for the treatment of certain skin diseases, such as psoriasis, ichthyosis vulgaris, xerosis, and pruritus in atopic dermatitis. More often, they are bases or vehicles for topical medication, such as in Whitfield’s ointment. They are often combined with humectants, such as salicylic acid and urea.Moisturizers are also widely used in sunscreens, antiperspirants, skin cleansers, shaving creams, aftershaves, and hair tonics.Moisturizers are used in disposable napkins to prevent dry skin and napkin dermatitis.A Cochrane review noted that moisturizers show some beneficial effects in eczema.
Persistent moisturization to the skin from exposure to water may contribute to an allergic reaction or irritant contact dermatitis, and can result in penetration of foreign objects. Changes in the skin’s normal ecological environment, in or on the skin, can also support the overgrowth of pathological organisms.
Moisturizers containing some aromas or food additives may trigger an immune reaction or even cause users to develop new allergies.There is currently no regulation over use of the term “hypoallergenic”, and even pediatric skin products with the label were found to still contain allergens. Those with eczema are especially vulnerable to an allergic reaction with lotions and creams, as their compromised skin barrier allows preservatives to bind with and activate immune cells.
The American Academy of Allergy, Asthma, and Immunology released a warning in 2014 that natural lotion containing ingredients commonly found in food (such as goats milk, cow’s milk, coconut milk, or oil) may introduce new allergies, and an allergic reaction when those foods are later consumed. A paper published in 2020 by researchers at St. George’s, University of London found that “frequent skin moisturization in early life might promote the development of food allergy, most likely through transcutaneous sensitization”.
Paraffin based skincare products and contaminated clothing can pose a serious fire hazard. Between 2010 and 2018, paraffin was linked to 50 fire incidents (49 of which were fatal) in the U.K. A West Yorkshire Fire and Rescue Service study found that clothing contaminated with cream containing only 21% paraffin, when set alight, was fully engulfed in flame in 3 seconds. The Medicines and Healthcare products Regulatory Agency (MHRA) released a warning in 2008 about the flammability of paraffin-based products. MHRA recommends that sheets of people using paraffin are changed regularly, and that people refrain from smoking or bringing open flames around patients using paraffin. MHRA also recommends that skin creams containing any paraffin have a flammability warning on the packaging.