Making the Choice
- Volume 12 - Issue 6 - June 2004
- Posted: 9/4/2008 - 4:34pm
- 3639 reads
E very patient needs to cleanse and moisturize skin properly using suitable cleansers and moisturizers containing the appropriate ingredients. In patients with compromised or sensitive skin, proper cleaning and moisturizing is even more critical. Using too harsh a cleanser or an inappropriate moisturizer can, in many cases, exacerbate certain conditions and can cause contact dermatitis and other problems.
The plethora of cleansers and moisturizers available today makes it difficult to keep current with new ingredients and their actions — or to guide patients in the selection of these products. In addition, few trials have looked at cleansers and moisturizers and their therapeutic value.
“Dermatologists must understand the ingredients in the products their patients use and what they do to or for the skin. However, the market changes quickly and it is very difficult to keep up,” says Zoe Diana Draelos, M.D., P.A., Clinical Associate Professor, in the Department of Dermatology at Wake Forest University. “They need to keep abreast of this as much as they keep abreast of any aspect of their medical practice by reading journals and going to meetings This aspect of the dermatology practice is just as important as any other, since cleansers and moisturizers have a dramatic impact on the skin.”
What to Look for in a Moisturizer
Xerosis occurs when the water content in the skin is less than 10% to
20% — depending on the measurement method, and there is loss of continuity of the stratum corneum. While moisturizers cannot repair skin, they can help restore the skin barrier and protect the skin as it heals. “Moisturizers need to stop water loss, decrease itching and burning, and make the skin feel smooth and soft,” says Dr. Draelos. “This creates an optimal environment for healing. Because the skin turns over every two weeks, healing can occur rapidly.” A good moisturizer should also be hypoallergenic, non-sensitizing, and non-comedogenic.
The ingredients in moisturizers are often divided into occlusive agents, humectants, and emollients. Occlusive agents physically prevent or retard water loss. The most effective occlusive moisturizer is petrolatum. Lanolin, mineral oil, and silicones, such as dimethicone, are also very effective occlusive moisturizers. Applying an occlusive moisturizer immediately after bathing may be an effective way to trap additional water in the skin.
Humectants attract and bind water and can improve hydration of the stratum corneum. Effective humectants include propylene glycol, glycerin, urea, hyaluronic acid and pyrrolidonecarboxylate (NaPCA). However, high levels of humectants can draw water from surrounding cells and can actually dry the skin further. if not trapped by an occlusive agent.
Emollients soften or soothe the skin by filling spaces between skin flakes and creating a smooth skin surface. They are usually light oily substances, such as octyl octanoate, sesame oil, grape seed oil, or cetyl stearate. Some emollients can also function as occlusive moisturizers. When combined with an emulsifier, the oily emollients are thoroughly mixed with the other water soluble ingredients in the moisturizer. Emollients are probably the most important consumer ingredient in moisturizers since they provide the smooth skin feel associated with well moisturized skin.
Moisturizers may contain additional additives such as vitamins E, A, C, niacin, panthenol, peptides, polyphenols, aloe vera, and others. Alpha hydroxy acids, such as lactic acid or glycolic acid, may also be added to decrease cohesion of the excess stratum corneum cells, reducing roughness and scaling. The special ingredients are designed to function as cosmeceuticals imparting unique attributes to standard moisturizer formulations. Their final efficacy depends on how much of the ingredient is in the moisturizer and how the final formulation interacts with the skin.
Despite their benefits, many patients resist using the most effective moisturizers since they often have unappealing characteristics. “Petrolatum is actually the very best moisturizer available, but it stains clothing, smells bad and is greasy,” says Dr. Draelos. “Every other moisturizer on the market is trying to achieve the benefits of white petrolatum without the bad aesthetic effects.”
According to Dr. Draelos, a good moisturizer should start with an occlusive agent, such as petrolatum or mineral oil, which is not as thick or greasy. It should also include occlusive ingredients that reduce greasiness, such as dimethicone, a type of silicone. “You might add grape seed, sesame or some other light weight oil and emollients, such as cetearyl alcohol,” says Dr. Draelos. “These are oils that can fit between the dry skin cells and make the skin feel smooth and soft.” It is also now possible to synthetically produce ceramides, which are some of the newest occlusive agents to enter the marketplace.
Dr. Draelos is excited about some of the newer developments in moisturizers. “The next generation of moisturizers are moisturizers used in a shower. Patients put the moisturizer on in the shower, and then rinse off. This novel technology effectively moisturizes the skin with long-lasting effects and is known as a new category of skin care products known as moisturizes.”
What to Look for in a Cleanser
Excessive cleaning can damage the skin by washing out the natural humectant agents, change the pH value of the skin and cause irritant contact dermatitis. “Cleansing damages the skin because the soap cannot distinguish between unwanted dirt and intercellular lipids,” says Dr. Draelos. “Synthetic detergents known as syndets are not as effective at removing dirt, but they do not remove as many intercellular lipids and are pH adjusted. A good alternative is the newer body washes that remove dirt, but leave behind a thin layer of petrolatum, especially if used with a puff.”
When cleansing, all patients should use warm — not hot — water and bathe for not more than 10 minutes. Cleansing agents should be spread sparingly on the wet skin and, after briefly taking effect, completely rinsed off. “When looking for a cleanser, most patients should avoid cleaners with parabens, fragrances and detergents. Patients should also avoid detergents such as sodium lauryl sulfate,” says Leslie S. Baumann, M.D., Director of Cosmetic Dermatology at the University of Miami. “Ingredients to look for depend on the skin type, but acne-prone patients should look for cleaners with salicylic acid, while those with rosacea would look for sulfacetamide.”
Some people with acne may try to stop outbreaks and oil production by scrubbing their skin and using strong detergent soaps and rough scrub pads. However, scrubbing will not improve acne; in fact, it can make the problem worse. Astringents are not recommended unless the skin is very oily, and then they should be used only on oily spots. Patients with acne should use a mild cleanser (5% benzoyl peroxide wash), once in the morning, once in the evening and after heavy exercise.
Acne suffers generally have oily skin, but the skin barrier can be compromised by treatment, leading to flaking and itching.
“I recommend skin lubricants in the silicone family like cyclomethicone and dimethicone, which soften and hydrate without oils,” explains Mary Lupo, M.D., a dermatologist in private practice in New Orleans and professor of dermatology at Tulane University Medical School in New Orleans. “Cleansers should be mild if on treatment, but high surfactant cleansers or those with salicylic acid are good for oily and acne prone skin.”
Eczema and Other Dermatoses
Any skin disease will benefit from a moisturizer that strengthens the stratum corneum barrier, even blistering bullous pemphigoid. Moisturizing with a good moisturizer is also very important for a disease such as psoriasis. “Since this is a disease characterized by hyperkeratosis, keratolytics can play an important role in its treatment. Propylene glycol and lactic acid can be sole, or integral parts, of treatment regimens by effectively removing adherent scales,” says Andrea Trowers, M.D., a pediatric dermatologist who has completed a fellowship in pediatric dermatology at the University of Miami. “Plastic wrap, plastic gloves or plastic shower caps can be used to occlude the affected area after application of a keratolytic, resulting in increased efficacy.”
Patients with eczema usually have an impaired stratum corneum barrier so they can benefit from a moisturizer that will help replace cholesterol, ceramides and fatty acids. The only skin diseases that generally do not benefit from a moisturizer are conditions that are skin manifestations of internal diseases such as skin cancer.
Photoaged skin is generally treated with retinoids, which can dry the skin, especially during winter. For these patients, applying a moisturizer is helpful. The best moisturizing agent is petroleum jelly, but it is too greasy for most people, though a creamy version is available that is almost as moisturizing as the original. If other moisturizers are used, they should be the cream versions of the moisturizer.
“Patients with photo-aged skin should avoid detergent cleansers with lots of surfactants. And they should look for added emollients like petrolatum to soothe,” explains Dr. Lupo. “Sodium laurel sulfate and many polysorbates can be very drying. Moisturizers with safflower oils and ceramide complexes are good. Humectants like glycerin are good as well.”
Patients with darker skin tones, often referred to as “ethnic skin,” have special concerns. “Ethnic skin is generally no more or less sensitive that lighter skin, and all the same precautions apply,” says Heather Woolery-Lloyd, M.D., Director of Ethnic Skin Care for the University of Miami Department of Dermatology. “However, ethnic or darker skin is subject to certain conditions not usually associated with lighter skin, such as hyperpigmentation following irritation.”
If a cleanser or moisturizer causes an irritation on a fair-skinned person, any redness heals and the skin returns to its normal appearance. However, a darker-skinned individual may be left with dark brown patches on their skin, which is especially bothersome if it occurs on the face. Excessive scrubbing and harsh cleansers in patients with conditions such as rosacea and seborrheic dermatitis heighten susceptibility to irritation that can lead to hyperpigmentation. Those patients should use the mildest cleanser and least irritating moisturizers.
“While it is difficult to specifically predict which individuals will be irritated by a particular ingredient, a dermatologist should make sure that patients use products with fewer known irritants,” says Dr. Woolery-Lloyd. “Soapless cleansers are generally milder than traditional soaps and are especially useful in patients with sensitive skin prone to irritation. Additionally traditional soaps combine with minerals in hard water and can leave an unwanted residue on skin and hair.”
Patients with pseudofolliculitis barbae may find that cleansers with glycolic acid offer some relief. In addition, shaving gels with salicylic acid can be effective against in-grown hairs. However, these products can be very irritating and should not be used for individuals with sensitive skin.
Another issue with darker skin is the ashy appearance of the skin when it becomes dry. While not necessarily a medical issue, it is still of concern to darker-skinned individuals. “Patients with dry, ashy skin will find products with lactic acid or urea to be effective,” says Dr. Woolery-Lloyd. “Because they not only moisturize and hydrate the skin, but they also exfoliate the superficial dry scale.”
Since elderly patients do not produce a lot of sebum, their skin is dry and prone to itchiness. As a result, the elderly need to be especially careful about skin care. They should wash less frequently, and should avoid cleansers as much as possible, relying almost exclusively on warm, not hot, water to rinse away surface dirt. Mild soap, such as glycerin soap, should only be used for local cleaning of especially soiled areas.
The elderly should moisturize frequently, especially after bathing when the skin is still moist. Bath oil can also be used, but patients must be careful about slipping.
Moisturizing is very important in pre-pubescent children since they do not produce a lot of sebum, and they generally get dirtier and require frequent bathing, which dries the skin.
“As far as moisturizers, individuals with healthy skin can use most of the products. Just pick a product that leaves skin smooth, not tight or greasy,” says Dr. Lupo. “A combination moisturizer and sunscreen is an excellent choice, because you can hydrate the skin and have the added benefit of preventing aging skin and skin cancers.”
“Young children with ethnic skin who have dry skin — especially those living in colder climates — can relieve the dryness and alleviate the ashy appearance by using products like petroleum jelly or even vegetable shortening that has been refrigerated for a cooling effect,” says Dr. Trowers. Older children often resist this approach because of the greasy feel, but products such as Cetaphil emollient cream can be almost as effective, with better cosmetic tolerance.
According to Dr. Trowers, children of all skin types who suffer from atopic dermatitis often have more bacteria on the surface of the skin. More severe cases can be cleansed below the neck with chlorhexidine, or in milder cases with a product such as Cetaphil anti-bacterial soap, then bathed in a solution of Alpha Keri bath oil.
Understanding the Ingredients
Considering the difference that proper cleansing and moisturizing can make to dermatology patients, it is essential that every dermatologist understand the ingredients that go into moisturizers and cleansers — and the impact that those ingredients have on a patient’s skin. “Good practice in cleansing and moisturizing can make a significant difference for patients with certain skin conditions and as a therapeutic response to the side effects of medications used for treatment,” says Dr. Baumann. “It is very important for dermatologists and their patients to become familiar with the individual ingredients in moisturizers and cleansers and to know what they really do. Without this knowledge, you may not be able to respond appropriately because your patient has come in with an unfamiliar product, and you are unable to offer sound medical advice.”