When it comes to acids and exfoliation in skin care, many questions can arise in the treatment room regarding choosing the most effective professional treatments, as well as making the best possible home care recommendations. Common questions estheticians ask are, “How do I choose the best acid for my clients’ concerns with their skin?” or “What exactly is this acid doing to the physiology of the skin to provide benefit for this specific skin condition?” With the vast variety of acids available to estheticians in skin care, determining the best acid for each skin condition can often become overwhelming. One of these acids, Salicylic acid, is a miracle ingredient that has been used throughout history to treat multiple ailments, and today, it is used to effectively treat a variety of skin conditions.
Before salicylic acid was known as an exfoliating agent and used in chemical peels and acne treatments, willow bark from the White Willow Tree (Salix Alba) was used for centuries to treat a multitude of conditions, which included treating aches and pains as well as reducing fevers. The inner bark of the willow tree contains a naturally-occurring chemical called salicin, which is one of the bark’s actives that provides its innate anti-inflammatory properties by blocking specific hormones that regulate inflammation. With the advances of science and chemistry over the years, it was discovered that salicin could then be oxidized and converted into the modern ingredient known as salicylic acid, leading to the creation of remarkable modern-day medicines, such as aspirin and results-oriented skin care treatments.
WHO IS IT FOR?
As a general statement, salicylic acid is primarily used on oily, congested and acne-prone skin types and this is due to salicylic acid being a lipophilic or oil-soluble acid, which means that it has the ability to break down sebum. It also softens and breaks down keratinocytes (or skin cells) and increases their shedding. Another unique aspect of salicylic acid is that is has a smaller molecular structure than other hydroxy acids, which facilitates its ability to penetrate deeper into the follicle, clear congestion and pore blockages, as well as prevent new blockages from forming. These benefits extend to breakouts on the body and salicylic acid can be included in formulations for face and body washes, masks, serums, moisturizers and peels.
Ironically, a disadvantage that can present itself when using salicylic acid is also due to its particle size. Due to the smaller molecular structure, the acid penetrates deeply and quickly into the follicle, beginning to break down skin cells and sebum almost immediately upon contact. Using higher percentage-formulated salicylic acid peels could potentially create unintended inflammation and irritation. Salicylic acid can also cause frosting or blanching in the skin, which presents a challenge for skin tones that fall into higher Fitzpatrick categories due to their predisposition towards inflammatory pigment reactions.
For skin tones on the Fitzpatrick scale of four or greater, there is a higher content of melanin in the skin as well as an increased melanocyte reaction to inflammation. All forms of physical trauma and injury cause an inflammatory reaction, including heat exposure, UV damage, laser treatments, and chemical peels. As a reaction to the trauma, melanocytes or pigment-producing cells release pigment as a form of protection, intended or not, causing a darkening of the pigment of the skin which becomes an increasing challenge to treat. Despite salicylic acid being anti-inflammatory by nature, when it is in a peel formulation with an acidic pH and larger percentages, the exfoliating properties also increase, leading to causing potential pigment inducing trauma to the skin.
Thankfully, new technology with salicylic acid is available, making it a safe and effective ingredient to use on virtually all skin types and tones. This technology is encapsulation, which utilizes vegetable lipids to surround the particle of salicylic acid with a lipid sphere or capsule that time releases the salicylic acid into the skin, avoiding potential irritation and side effects. This same technology also facilitates even deeper penetration and greater adhesion to the structure of the skin versus traditional salicylic acid, allowing superior results from lower percentage formulations. Furthermore, the encapsulation technology creates the opportunity for sensitive or rosacea skin types and Fitzpatrick four or higher skin tones to receive salicylic acid peels, which normally is contraindicated.
ADDITIONAL USES
There are three categories of acids that are typically utilized in skin care: Alpha Hydroxy, Beta Hydroxy, and Alpha Keto Acids. Alpha Hydroxy and Alpha Keto Acids differ from Beta Hydroxy (salicylic acid) in the fact that they are water-soluble and break down the water-based chemical bonds or cement that holds skin cells together. Alpha Hydroxy Acids are typically derived from fruits, such as grapes, apples, and lemons, as well as milk, while Alpha Keto Acids can be derived from fruit or flower sources. These acids also have the potential to increase hyaluronic acid and stimulate collagen, which makes them ideal for dry, aging and hyperpigmented skin types.
As the body ages, the strength of the glue that holds the layers of skin cells together increases, leading to an augmented layer of corneocytes or the topmost layer of skin cells within the epidermis. This is also due to a decrease in new cell production and change in cellular turnover rates. These corneocyte cells are flat, brittle and become dehydrated as they migrate to the top, which is partially responsible for the increase in dullness and change in the texture of the skin with age. With this increased thickness comes a resistance to penetration of product as well as impeding the action of Alpha Hydroxy Acids, which can have a difficult time penetrating through this thickened layer on their own. Salicylic acid is an additional tool that, when combined with Alpha Hydroxy Acids, can function to drive penetration and increase both ingredients’ effectiveness, providing increased benefits for advanced aging skin types. It’s the equivalent of adding a bulldozer to the demolition crew of the skin to knock down the structure and walls more effectively.
Salicylic acid also provides relief for psoriatic skin conditions by increasing skin shedding and relieving inflammation. By nature, psoriasis is an overabundance of skin cells creating a distinctive appearance of “scaling,” resulting in an interference of essential skin function. The common symptoms that follow are itching, irritation and inflammation as a reaction, which many clients find unbearable. Due to salicylic acid’s properties (anti-inflammatory, keratinocyte softening), it is an effective treatment to manage psoriasis symptoms and, when used as an encapsulated delivery system, could potentially make it even more effective. This is due to an increase in the depth of penetration as well as the length of active exfoliation, all while avoiding potential negative effects because of the time-released delivery the encapsulation technology provides.
Keratosis Pilaris is another skin condition that salicylic acid provides relief of symptoms for. Keratosis Pilaris is a skin condition most commonly occurring on the backs of the arms, but it can also occur on the legs, face and back, distinguished as dry, red, raised bumps. While the exact root cause is still unknown, Keratosis Pilaris develops when dead skin cells plug and congest the hair follicle, and sufferers often find it difficult not to pick the bumps, leading to excoriation, inflammation and sometimes scarring. Due to salicylic acid’s keratinocyte softening and exfoliating properties, it facilitates the clearing of the follicle from dead skin cells and provides relief of the associated inflammation. Combining salicylic acid with glycolic acid or lactic acid (both Alpha Hydroxy Acids) gives additional benefit through an increase in hydration and moisture barrier function. Continued use of both acids in milder formulations can also function as a preventative treatment to reduce Keratosis Pilaris reoccurrence.
In summary, salicylic acid is an invaluable tool, both in the treatment room as well as for clients’ home care systems, varying from an ingredient utilized in an anti-acne cleanser or moisturizer, to an effective peel option for a variety of skin conditions. In addition, it provides an effective way of boosting anti-aging treatments when combined with Alpha Hydroxy Acids to facilitate better penetration, deeper exfoliation and an increase in the clearing of dead skin cells. The encapsulation technology now available also makes the uses of salicylic acid seem boundless, as this delivery system allows usage on skin conditions which traditionally don’t tolerate salicylic acid application.
Salicylic acid has come a long way from the days when tree bark was applied directly to the skin!
