Many people get dry, itchy skin during the cold winter months. But if you have atopic dermatitis—a form of eczema—flare-ups of red, itchy, flaky patches can be common year-round. Atopic dermatitis is an inflammatory skin disorder that occurs, in part, when skin is deficient in lipids and natural moisturizing factors (a mixture of amino acids). Lipids make up the skin’s natural barrier, the outer layer that protects it against allergens, irritants, and bacteria.
Daily moisturizing is a mainstay of maintenance therapy to help hydrate the skin, restore its barrier, and keep eczema symptoms at bay. Moisturizers work by preventing the evaporation of water from the skin, thereby locking in moisture. If you have eczema, your dermatologist can recommend a moisturizer, but sometimes it’s a matter of trial and error. What works for some people may not work for you.
What to look for in a moisturizer
The more oil a moisturizer contains, the more effective it is for treating eczema. Moisturizers are available in three main formulations:
1. Ointments. Ointments have a high oil content and contain little to no water, making them an effective remedy for mild to moderate eczema. Petroleum jelly (Vaseline) is one of the best ointments for eczema. Some ointments, such as Aquaphor Healing Ointment, may contain additional ingredients like lanolin, beeswax, silicones, and mineral oil. Ointments help the skin retain water better than other moisturizers but can feel greasy.
2. Creams. Thick creams like Eucerin Advanced Repair Creme and Cetaphil Intensive Moisturizing Cream help seal in moisture while keeping out irritants and are less greasy than ointments. Creams that contain lipids or ceramides—the same components as in the skin’s natural barrier—can help form a protective layer.
3. Lotions. Lotions aren’t recommended for people with eczema because they contain more water than oil and aren’t as effective as ointments and creams. Any benefit is short lasting—because of their high water content, lotions evaporate quickly on the skin. Plus, they can occasionally make eczema worse.
Moisturizers can be subdivided based on their ingredients and how they work:
?Emollients contain lipids that give the skin a smoother appearance. They protect the skin, filling in any cracks or gaps between skin cells and evening out the surface. Popular emollients include beeswax, aloe vera, and shea butter as well as jojoba, coconut, argan, and other oils. Some people report a burning or stinging sensation when using them.
?Humectants help the skin absorb water from the atmosphere. Humectants such as glycerin are used as the base for many moisturizers. Alpha-hydroxy acids, which include glycolic and lactic acid, are double-duty humectants that shed dead skin cells. Urea, lactic acid, and amino acids are three natural moisturizing factors. Hyaluronic acid is also a popular humectant, although it can be expensive.
?Occlusives consist of the waxy oil extracts found in ointments. They’re made from vegetable, fat, or mineral extracts.
Many moisturizers combine emollients, humectants, and occlusives. So if an occlusive does the job for you, but you don’t like its greasy feeling, look for one that’s paired with a light emollient or glycerin.
According to a Cochrane review of 77 randomized controlled trials, published in November 2017 in the British Journal of Dermatology, certain moisturizer ingredients helped control mild to moderate eczema symptoms and reduced the frequency of flares better than other products or no moisturizers at all. The most effective included glycyrrhetinic acid, urea, and glycerol (glycerin, glycerine). Although many studies reviewed were small and the overall quality of evidence was low, most moisturizers appeared to be effective at reducing eczema flare-ups, and no one moisturizer clearly outperformed any other.
Some moisturizers are available by prescription, but few studies have compared them head to head with over-the-counter (OTC) products. At least one study found that prescription moisturizers were no more effective than OTC products—and prescriptions were more costly.
Ingredients to avoid
When choosing a moisturizer, look for products that are free of fragrances and dyes. They can irritate sensitive skin, as can some preservatives, including quaternium-15; imidazolidinyl urea; DMDM hydantoin; 2-bromo-2-nitropropane-1,3-diol; and diazolidinyl urea.
Additional research is needed to confirm which moisturizers are safest and most effective for eczema. Finding the right moisturizer can take some time and experimentation. And even the best cream might not be enough to relieve your eczema flare-ups on its own; if that's the case, your doctor may recommend a topical or oral prescription medication.
This article first appeared in the May 2018 issue of UC Berkeley Health After 50.
Also see Moisturizers: Slippery Claims.