Moisturizer plays a crucial role in everyday skincare, especially when there's a change in the skin's protective layer and a decrease in the amount of water in the skin. It's a key element in a dermatologist's approach to keeping the skin healthy and treating various skin conditions that often occur with dry skin and are associated with a weakened skin barrier, including atopic conditions and other forms of dermatitis. It's essential for a dermatologist to understand how moisturizers work, how to apply them, the right amount to use, potential side effects, and their specific uses in clinical settings to effectively recommend them, especially for treatment based on solid evidence. This article explores the use of moisturizers for both maintaining skin health and as a primary or supplementary treatment for various dermatitis types.
What is moisturizer
It's quite intriguing that there's no universal agreement on what exactly a moisturizer is. This term was coined by advertisers to highlight its role in hydrating the skin. Often, moisturizer and emollient are seen as interchangeable, even when they include other ingredients like occlusives and humectants. Emollients, primarily composed of lipids and their derivatives, are designed to fill the spaces between skin cells, improving skin hydration, smoothness, softness, and flexibility. Occlusives, another kind of moisturizer, are usually oil-based and work by keeping the skin's moisture levels up by forming a protective layer that prevents water from escaping through the skin. The final category of moisturizers are humectants, which are made of substances that can pull water from the deeper layers of the skin and the surrounding air, bringing it into the outermost layer. The effectiveness of a moisturizer largely hinges on choosing the right one and making sure to use it consistently.
Having healthy-looking skin is crucial because poor skin appearance can lead to lower self-confidence. Using moisturizers is a common way to lessen the appearance of small lines, make the skin smoother and more hydrated, which can enhance a person's social interactions, mental well-being, and overall life satisfaction.
Additionally, both individuals with normal skin and those suffering from skin conditions that cause dryness can benefit greatly from the correct use of moisturizers. Dry skin is characterized by both visual and physical changes in the skin, as well as changes in the skin's ability to sense, leading to dry skin symptoms. These symptoms include a feeling of dryness, as well as discomfort, such as tightness, pain, itchiness, stinging, and tingling. Moisturizers are effective in treating the root cause of dry skin conditions, breaking the cycle of dryness, and keeping the skin smooth.
The skin serves as a protective layer, shielding the deeper tissues from drying out, infections, physical stress, and chemical irritation. When its function is compromised, there's an increase in water loss from the skin's surface, leading to various forms of dermatitis.
Water from the deeper layers of the epidermis rises to nourish the top layer of skin cells and is subsequently lost through evaporation. The amount of water in the epidermis is crucial for preventing the skin from becoming dry and maintaining its flexibility. The top layer of skin, known as the stratum corneum, is an active barrier, likened to a bricks and mortar model. The loss of lipids between skin cells, which form the barrier, can damage it, resulting in dry skin.
The composition of the stratum corneum plays a key role in the movement of water, its retention, and the overall level of moisture in the skin. There are four main processes involved in the formation and function of the stratum corneum: corneocyte, stratum corneum lipid, natural moisturizing factor, and desquamation. Corneocytes are the physical barrier of the stratum corneum, contributing to its elasticity when they are hydrated. The lipid bilayers of the stratum corneum act as a barrier to moisture but also allow the entry of many substances applied topically. The natural moisturizing factor found in corneocytes is a combination of hygroscopic molecules that help maintain the hydration of corneocytes. About half of the natural moisturizing factor comes from amino acids derived from keratinocyte protein filaggrin, with the rest being salts like lactates, urea, and electrolytes. The production of natural moisturizing factor is influenced by the humidity of the environment. In the process of desquamation, corneodesmosomes are broken down by water-dependent enzymes, which are less effective in dry skin conditions. Dry skin conditions occur when corneocytes accumulate on the skin's surface, leading to a loss of skin continuity.
Creams and lotions enhance the repair of the skin's protective layer, maintain its health and look by functioning as attractants, softeners, and barriers, all through unique methods of operation. These products not only boost the skin's moisture levels and elevate the amount of water in the top layer of the skin by supplying water directly to the skin from their liquid phase and by increasing the protection barrier against losing water through the skin, but also seal minor cracks, offer a calming layer of protection, and shield the skin from rubbing. Moreover, the use of these products evens out the texture of the skin by smoothing out gaps between skin flakes that are still attached and helping the skin's inner layers to soak up, hold onto, and spread water again. Skin function evolves further with more moisture allowing the skin to break down corneodesmosomes, which helps prevent too much corneocytes from gathering and instead keeps them connected. Summarizing, these skin care items do more than just sit on the skin's surface; they also go deeper to affect the skin's structure and operation.
Moisturizer application method
The perfect timing and techniques for applying moisturizers are crucial for achieving the best results. Besides humectants and hydrophilic substances that draw moisture from the air or deeper skin layers, the frequently used occlusive oils are best applied to skin that has been dampened either through a shower or sponge bath. Following the application of moisturizer to both hands, it's important to gently spread it along the direction of hair follicles. To avoid the risk of oil folliculitis from too much rubbing, it's essential to clearly instruct the patient on the proper application techniques.
The way moisturizer is spread out depends on the type of formula used. Heavier ointments tend to distribute more uniformly than those with lower viscosity and volatile components. It's easier for active ingredients in creams and ointments to reach the surrounding areas compared to lotions and tinctures. Following application, the ingredients can remain on the skin's surface, be absorbed, metabolized, or simply disappear through evaporation, shedding, or interaction with other substances. By the end of 8 hours, only half of the moisturizer was left on the skin's surface. Thus, the recommended frequency of application varies based on how dry the skin is, ranging from once to three times daily.