Topical Skin Care and the Cosmetic Patient

Cleansers and Toners

Cleansers are the most basic component of a skin care regimen. Cleansers are designed to remove dirt, bacteria, makeup, and pollution from the skin and to prepare the skin for product application. Gentle cleansing is dependent on the composition and pH of the cleanser. Many cleansing products contain surfactants that disrupt stratum corneum proteins and lipids, resulting in compromised barrier function . In addition, cleansing products such as true soaps have an alkaline pH, causing skin irritation. Thus, cleansing products with a neutral or slightly acidic pH are preferable in the clinical setting.

There are four general categories of cleansing products including true soaps, synthetic detergent bars (syndets) and cleansers, combination bars (combars), and lipid-free cleansers. True soaps are made through saponification, which is the chemical reaction between a fat and a base such as lye. These high-pH cleansing bars are excellent for cleansing the skin but damage stratum corneum lipids and proteins. Repeated use of true soaps causes dehydration of the skin and should be avoided. Syndets were developed to address the problems created by cleansing with true soaps. Syndets are soap bars and cleansers that contain less than 10% true soap in combination with synthetic detergents. With a more favorable pH of 5.5–7, they can be used daily without causing dry or irritated skin . Syndets have been tested in patients with sensitive skin and conditions such as rosacea, and are well tolerated. Lipid-free cleansers are liquid products that cleanse the skin without the use of fats. They can be used on dry or wet skin and are massaged to create lather. Lipid-free cleansers have excellent tolerability and leave behind a thin moisturizing film on the skin . Patients who have undergone resurfacing or peeling procedures may benefit from the gentle cleansing and moisturization provided by lipid-free cleansers. Table 5.1 lists mild cleansing products that are appropriate for postprocedure patients. Combars are soaps with antibacterial agents such as triclosan. These are often used to prepare patients the night before or the morning of a surgical procedure. Combars are not appropriate for daily use on the face as they can be drying.

Moisturizers

Chronologically aged skin is characterized by an inherent reduction in epidermal lipid content, resulting in dehydration and altered skin barrier function . Epidermal keratinocyte differentiation and desquamation slows with age, leaving skin dry and flaky. Dry skin is a common cause of itching in older patients, and in more severe cases leads to cracks and fissures that impair function. Thus, the use of properly formulated moisturizers is essential for patients with aging skin. It is also important to note that moisturization alone can improve skin wrinkling. A temporary plumping of the skin occurs after moisturizer is applied, making lines and wrinkles less noticeable and giving the skin a dewy appearance. This is why vehicle-controlled studies are so important for confirming the long-term benefits of cosmeceutical moisturizers.

Most commercially available moisturizers are oil in water emulsions. Moisturizers contain approximately 80% water in combination with occlusive, humectant, and emollient ingredients . Ingredients such as petrolatum, lanolin, and mineral oil form an occlusive layer on the surface of the skin increasing stratum corneum hydration by preventing transepidermal water loss. Glycerin, hyaluronic acid, sodium lactate, and urea act as humectants that attract water from the dermis upwards into the epidermis and stratum corneum. Emollients are the ingredients that are responsible for the smooth feel of the skin that is felt after a moisturizer has been applied. Emollient ingredients include lanolin, sunflower, and jojoba oil.

Moisturizers include creams and lotions that differ in their physical properties and chemical composition. Creams contain more oil, less water, and are thicker and more occlusive than lotions. Patients with more advanced skin aging generally prefer creams over lotions. Creams are also beneficial to treat special areas such as the eyes, décolletage, and neck. Lotions are easy to spread, making them good for treating larger surface areas of the body.

Choosing a moisturizer can be daunting, since consumers are faced with so many options. Postprocedure patients should be advised to use bland moisturizers, meaning those that do not contain additives such as alpha hydroxy acids (AHAs), urea, and retinol. These ingredients can be irritating, causing redness, stinging, and burning of recently treated skin. In contrast, moisturizers with actives such as ceramides, niacinamide, or hyaluronic acid are preferable, since they provide effective skin hydration and enhance barrier function without irritation .

It seems counterintuitive, but patients with oily skin and those who are acne prone also need moisturizers. Studies have shown that acne patients suffer from defective barrier function that is exacerbated by the use of acne medications. Salicylic acid, benzoyl peroxide, and retinoids all have local adverse effects including irritation and dry skin. The concomitant use of moisturizers in acne therapy improves tolerability, and enhances efficacy and skin comfort . There are many oil-free moisturizers to choose from that do not contain mineral or vegetable oils. Oil-free moisturizers use silicone derivatives such as dimethicone and cyclomethicone to retard moisture loss without the greasy feel.

Sunscreen

Sunscreen is perhaps the most important component of an antiaging skin care regimen. Sunscreens are the only topical treatments that have been shown to prevent skin aging and are essential in patients undergoing cosmetic procedures . Current photoprotection strategies include the use of primary and secondary photoprotectors. Primary photoprotection includes sunscreens and sun-protective clothing that prevent ultraviolet (UV) light from reaching the skin. Secondary photoprotection refers to the use of antioxidants and DNA-repair enzymes that can mitigate damage caused by UV light .

Sunscreens are traditionally divided into organic and inorganic types . Inorganic sunscreens utilize particles to scatter and reflect UV light. These particles include zinc oxide and titanium dioxide in micronized forms and essentially block UV light from entering the skin. Thus, they are aptly referred to as sunblocks or chemical-free sunscreens. Inorganic sunscreens are an excellent choice for postprocedure patients. They are relatively free from potential allergens and irritating chemicals. Newer formulations with micronized forms of zinc and titanium dioxide provide a more translucent appearance that is cosmetically acceptable. Inorganic sunscreens are an excellent choice for patients with hyperpigmentation or melasma, as they effectively block both UV A (UVA) and UV B (UVB) rays. They are also of value for preventing postinflammatory hyperpigmentation that can occur following resurfacing procedures and peels. Powder-based mineral sunscreens are popular with consumers and can be applied several times a day over moisturizer and makeup. These powders contain organic ingredients and provide excellent photoprotection.

Organic sunscreen ingredients absorb UV light energy and transform it into heat. Commonly used UVB-absorbing ingredients include cinnamates, salicylates, octocrylene, benzophenones, and menthyl anthranilate. Effective UVA-absorbing ingredients such as avobenzone and ecamsule are now widely available, and offer expanded broad-spectrum photoprotection. Although most organic sunscreens are well tolerated, there is a small risk of contact dermatitis from ingredients like cinnamates and oxybenzone .