Cleansing is one of the most important steps in any skin care routine, but the surfeit of products on the market can lead to patients selecting an inappropriate cleanser for their skin type. This can engender various adverse cutaneous effects, including xerosis, flaking, acne, and flare-ups of chronic skin conditions such as eczema and rosacea. For example, acne medications are better tolerated when the proper cleanser is used. Cleanser choice is particularly important for individuals with dry skin who have an impaired barrier and those with sensitive skin who are susceptible to inflammation. The following discussion focuses on the factors that practitioners should address with patients when recommending cleansing products to help them maximize their outcomes and maintain clear, healthy-looking skin.
TYPES OF CLEANSERS
Anionic surface acting agents (surfactants or detergents) produce foam and display the greatest cleansing potency. (Table 1). Because these detergents remove lipids from the skin’s surface and protective bilayer membrane barrier, they should only be used only by individuals with increased sebum production. Ingredients in this category injure the skin barrier and make the skin more susceptible to irritant reactions.1 For example, the widely used compound sodium lauryl sulfate (SLS), which strips lipids from the skin, irritates the skin to such an extent that it is used in research labs to hinder the skin barrier to test “barrier repair products.” The “sulfate- free” trend originates from the irritation caused by SLS. The barrier disruption caused by SLS can be used to intentionally damage the skin barrier to allow increased penetration of chemical peeling products and other therapeutic agents. An alternative to SLS is sodium laureth sulfate (or sodium lauryl ether sulfate, also known as SLES), which exhibits foaming attributes but is less likely than SLS to cause irritation. We often use a foaming cleanser in our practice prior to injectable procedures to ensure that makeup and debris are removed from the skin, and to decrease the time needed for topical lidocaine to penetrate into the skin. If you adopt this strategy, you should follow the injectable procedure with a barrier repair moisturizer.
These agents were developed through efforts to reduce detergent irritancy. This class of cleansers includes superfatted soaps, combination bars (“combars”), syndet bars (composed of synthetic surfactants) and compounds that deposit lipids on the skin, such as creams, lotions and oils. Cream, milk, cold creams, and oil cleansers fall into this category. These products usually have a neutral pH, and include ingredients such as alkyl glyceryl, ether sulfonate, alpha olefin sulfonates, betaines, sulfosuccinates, sodium cocoyl monoglyceride sulfate, and sodium cocoyl isethionate. Organic nonfoaming agents are also available, and may include saponins, a large family of structurally related compounds derived from plant, and sucrose laurate. Nonfoaming cleansers are most appropriate for dry skin types. Oily skin types often report that they “do not feel clean” when they use these cleansers.
Hydroxy acid cleansers
Alpha hydroxy acids (AHAs) are well suited for use by individuals with dry skin because hydroxy acids act as humectants (water-soluble materials with high water absorption capabilities). These hydrophilic cleansers provide exfoliation, and are appropriate for individuals with dry skin and acne because their low pH contributes to an inhospitable microbiome for Propionibacterium acnes, making it harder for the bacteria to thrive. Importantly, the exfoliating activity imparted by hydroxy acids sets the stage for better penetration into the stratum corneum by ingredients applied subsequent to the cleanser. Alpha hydroxy acid cleansers do not dry out the skin the way that salicylic acid cleansers do because their hydrophilic nature makes them unable to penetrate through sebum.
Salicylic acid (SA) cleansers are a member of the aspirin family and therefore confer anti-inflammatory properties. Salicylic acid is lipophilic and can penetrate through the sebum derived lipids into pores. They are the most effective cleansers to unclog pores. Therefore, SA cleansers are ideal for use by individuals with oily, sensitive skin prone to acne, seborrheic dermatitis, or rosacea. The exfoliation yielded by salicylic acid also enhances skin barrier penetration by ingredients applied after its use and is well tolerated by individuals with oily skin. Dry skin types, especially those on retinoids and benzoyl peroxide, will not tolerate SA as well as they will AHA cleansers.
Antibacterial cleansers contain ingredients that reduce P. acnes and other types of bacteria on the skin. These products include benzoyl peroxide (BP), silver, hypochlorous acid, and sodium hypochlorite. Benzoyl peroxide can be highly irritating and is not well tolerated by patients with dry skin. Silver has a long history, having been used as an antibacterial agent since the times of King Herod. On the other hand, hypochlorous acid and sodium hypochlorite are novel entrants in the cleansing realm, particularly for individuals with acne. In fact, sodium hypochlorite is formulated to be mild enough for daily use while still sufficiently effective for acne-prone skin.