5/28- Role of Hydroxy Acids in Chemical Peel (250 words)

Chemical peeling is a dermatological procedure involving the application of chemical substances to the skin to induce controlled destruction of the epidermis, sometimes extending into the dermis, which subsequently promotes skin regeneration and remodeling. This treatment is widely sought-after in the realm of cosmetic procedures due to its ability to rapidly enhance skin quality. It effectively addresses various skin conditions including melasma, freckles, post-inflammatory hyperpigmentation, photoaging, under-eye circles, acne vulgaris, rosacea, and scars.

Chemical peels are categorized by their depth of penetration: superficial, medium, and deep. Superficial peels primarily target the epidermis without reaching the deeper layers. They are recommended for treating conditions such as photoaging, pigmentary disorders, and mild acne. Common agents used in superficial peels include AHA (alpha-hydroxy acids) like glycolic, lactic, and mandelic acids, BHA (beta-hydroxy acids) such as salicylic acid, TCA (trichloroacetic acid) in concentrations of 10-35%, Jessner solution, and tretinoin. These peels typically require minimal downtime.

Medium peels affect the epidermis and penetrate into the papillary dermis, addressing more pronounced signs of aging, pigmentation issues, and superficial scars. TCA (35-50%) and pyruvic acid (40-70%) are commonly used in medium peels, offering noticeable results with a recovery period of about one week.

Deep peels, the most intensive type, extend beyond the epidermis into the mid reticular dermis, making them suitable for severe photoaging, deep scars, and intense pigmentation problems. Phenol (88%) and higher concentrations of TCA (>50%) are utilized in deep peels, necessitating a longer recovery time of approximately 10 days.

The process of chemical peeling typically follows a structured protocol to optimize results and minimize risks. Preparation includes priming the skin with agents like tretinoin for enhanced peel penetration and uniform results. Cleansing immediately before treatment ensures the skin is free from oils and debris, facilitating effective peel application. The peel itself is applied for a specific duration depending on its depth and the desired outcome, followed by the application of soothing creams or bandages in some cases. Post-peel care involves strict hydration and sun protection to support skin healing and prevent complications such as hyperpigmentation.

Despite its benefits, chemical peeling is not without risks. The depth of the peel correlates with both therapeutic effects and potential complications. Individuals with darker skin tones or a history of scarring are particularly vulnerable and must adhere closely to pre- and post-peel care instructions. Immediate complications may include swelling, burning sensations, itching, or blistering, while delayed complications might manifest as pigmentation irregularities, demarcation lines, rashes, or infections. Medium to deep peels carry additional risks such as atrophic scarring and systemic issues like cardiac arrhythmias or toxic shock syndrome.

In conclusion, chemical peeling is a versatile cosmetic procedure appreciated for its ability to quickly improve skin texture and appearance. By selecting the appropriate peel depth and meticulously following procedural guidelines, dermatologists can achieve significant aesthetic enhancements while minimizing the likelihood of adverse effects. As with any medical intervention, thorough patient assessment, informed consent, and diligent post-treatment care are essential to ensuring safe and effective outcomes for all individuals undergoing chemical peeling.

Nikalji, N., Godse, K., Sakhiya, J., Patil, S., & Nadkarni, N. (2012). Complications of medium depth and deep chemical peels. Journal of cutaneous and aesthetic surgery, 5(4), 254–260. https://doi.org/10.4103/0974-2077.104913

Kornhauser A, Coelho SG, Hearing VJ. Applications of hydroxy acids: classification, mechanisms, and photoactivity. Clin Cosmet Investig Dermatol. 2010 Nov 24;3:135-42. doi: 10.2147/CCID.S9042. PMID: 21437068; PMCID: PMC3047947.

Chemical Peels

Written By: Claudia Kwasiborski

               Chemical peels are a technique used to improve the appearance of the skin on the face, neck, chest, and hands. This technique involves the application of exfoliants to the top layer of skin, which then ‘peels off’ and regenerates, also known as resurfacing. The indications for use of chemical peels is wide, ranging from cosmetic to therapeutic. Patients may receive chemical peels for signs of aging, melasma and hyperpigmentation, or acne vulgaris, among others. The benefits of chemical peels include improved skin elasticity, improved skin texture and skin tone. Chemical peels may be classified based on their strength, concentration, pH, and depth of penetration into the skin. The depth of penetration may range from superficial to deep.

The most common ingredient that is used in chemical peel solutions are a combination of hydroxy acids, which are classified as exfoliants. The choice of hydroxy acid depends on the benefits that the patient would like to see from their treatment. Alpha hydroxy acids (AHA) are chemicals used in superficial and medium- depth peels and are used to treat acne, skin discoloration, uneven texture, and wrinkles. AHAs include glycolic acid and lactic acid.  AHAs are highly effective and popular agents that are widely used, but can cause redness, burning, sunburn and UV- related malignancies, or scarring if proper application and aftercare is not followed. More severe adverse events can include anaphylaxis, corneal damage, and cardiotoxicity.  Beta hydroxy acids (BHA) are effective in reducing the appearance of fine lines and wrinkles and improving skin texture. Salicylic acid is most seen in professional and commercially available formulas. Salicylic acid is a strong chemical exfoliant that is primarily used for acne vulgaris but is suitable for use in targeting photoaging and pigmentation as well. BHAs carry less adverse effects, such as redness and swelling, and may be a more suitable option for patients that suffer from intolerable or more severe reactions from chemical peels using AHAs.  

                  Professional chemical peels are done in a dermatologist’s office by a trained individual with proper equipment. There are also multiple formulations available on the commercial market that are suitable for patients to use at home because they are weaker in concentration, and thus not as strong. AHAs and BHAs must be used with proper handling and caution in order to prevent any serious side effects, such as avoiding the eye areas, appropriate pre-treatment and after-care steps.

Citations:

Center for Food Safety and Applied Nutrition. “Alpha Hydroxy Acids.” U.S. Food and Drug Administration, FDA, 22 Nov. 2022, www.fda.gov/cosmetics/cosmetic-ingredients/alpha-hydroxy-acids. 

Center for Food Safety and Applied Nutrition. “Beta Hydroxy Acids.” U.S. Food and Drug Administration, FDA, 25 Feb. 2022, www.fda.gov/cosmetics/cosmetic-ingredients/beta-hydroxy-acids. 

Kornhauser A, Coelho SG, Hearing VJ. Applications of hydroxy acids: classification, mechanisms, and photoactivity. Clin Cosmet Investig Dermatol. 2010 Nov 24;3:135-42. doi: 10.2147/CCID.S9042. PMID: 21437068; PMCID: PMC3047947.

Samargandy S, Raggio BS. Chemical Peels for Skin Resurfacing. [Updated 2023 Oct 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK547752/

Tang SC, Yang JH. Dual Effects of Alpha-Hydroxy Acids on the Skin. Molecules. 2018 Apr 10;23(4):863. doi: 10.3390/molecules23040863. PMID: 29642579; PMCID: PMC6017965.

Chemical Peels

A chemical peel is a technique used to improve the appearance of the skin in the face, neck, or hands. It is a popular relatively inexpensive, and generally safe method for treatment of some skin disorders and to refresh and rejuvenate skin. A chemical solution is applied to the skin that causes it to exfoliate and eventually peel off. The new, regenerated skin is usually smoother and less wrinkled than the old skin. The new skin is also, temporarily, more sensitive to the sun. There are three basic types of chemical peels: superficial, medium, and deep peels.

Superficial peels are made up of alpha-hydroxy acid or another mild acid and are used to penetrate only the epidermis and dermal-epidermal interface of skin to gently exfoliate it. They are useful in the treatment of mild dyschromia’s, acne, post-inflammatory pigmentation, and help in achieving skin radiance and luminosity. Because of their superficial action they can be used on nearly all skin types. After a superficial peel, epidermal regeneration can be expected within 3-5 days. These peels exert their actions by decreasing corneocyte adhesions and increasing dermal collagen.

Medium peels are made up of glycolic or trichloroacetic acid and is applied to penetrate the outer and middle layers of skin to remove damaged skin cells. This treatment is used for dyschromia’s such as solar lentigines, multiple keratoses, superficial scars, pigmentary disorders, and textural changes. Sun protection is recommended for several weeks due to the longer healing process. There is an increased risk of prolonged hyperpigmentation, which is why these peels should be conducted with caution in patients with darker skin tones.

Deep peels are trichloroacetic acid or phenol is applied to deeply penetrate the middle layer of skin to remove damaged skin cells. These peels are used for severe photoaging, deep or coarse wrinkles, scars and sometimes precancerous skin lesions. These peels cause rapid denaturization of surface keratin and other proteins in the dermis and outer dermis. Deep peels maximize the regeneration of new collagen. Epithelialization occurs in five to ten days, but requires significant healing time, and increased sun protection.

Alpha hydroxy acids used in superficial peels include various acids including: glycolic acid, citric, malic acid, tartaric acid, and lactic acid, all of which are naturally-occurring organic acids present in many foods and milk sugars. These acids are used in a variety of treatments. These include the treatment of acne, acne scarring, and melasma. Although peels serve many benefits, they do come with potential side effects. Superficial peels are generally safe. They are tolerated with mild discomfort, such as transient burning, irritation, and erythema. The tolerability of peels may be influenced by factors such as peel agents, concentration, depth, skin type, and concomitant use of skin care products.

Using peels less frequently but on a continuing bases is seen to be beneficial to help keep improvement ongoing, especially for superficial peels. These peels remain popular for the treatment of some skin disorders and for aesthetic improvement and therefore understanding the different types, applications, and safety precautions necessary.

References

American Society for Dermatologic Surgery. (n.d.). Skin experts. https://www.asds.net/skin-experts/skin-treatments/chemical-peels

Tang, S. C., & Yang, J. H. (2018). Dual Effects of Alpha-Hydroxy Acids on the Skin. Molecules (Basel, Switzerland), 23(4), 863. https://doi.org/10.3390/molecules23040863

Rendon, M. I., Berson, D. S., Cohen, J. L., Roberts, W. E., Starker, I., & Wang, B. (2010). Evidence and considerations in the application of chemical peels in skin disorders and aesthetic resurfacing. The Journal of clinical and aesthetic dermatology, 3(7), 32–43.

Kornhauser, A., Coelho, S. G., & Hearing, V. J. (2010). Applications of hydroxy acids: classification, mechanisms, and photoactivity. Clinical, cosmetic and investigational dermatology, 3, 135–142. https://doi.org/10.2147/CCID.S9042

Written by Justin Ayob and Antonio Ortega

Hydroxy acids are a group of organic carboxylic compounds including glycolic acid (from sugar cane), citric acid (from citrus fruit), lactic acid (from milk and pickled vegetables), malic acid (from apples) and tartaric acid (from grapes). These treatments are recommend for those who have signs of wrinkled skin, fine lines, brown spots and is safe during pregnancy. Hydroxy acid works by getting rid of the old damaged skin cells so the skin can produce new healthy skin cells.

Hydroxy allows the dead skin to peel off gently to give a fresher healthier look. Hydroxy acid is an alternative recommendation for those who cannot commit to laser resurfacing. Treatments include for stabilizing oily or acne-prone skin and improving skin tone. There are several types of hydroxy acids used depending on how severe the skin condition is.

Glycolic, citric, lactic, malic and tartaric acid are types of Alpha hydroxy acids used for mild chemical peel. These peels are typically used to reduce the appearance of fine lines, smooth rough skin and produce a more even skin tone and can help with acne. Because these are mild chemical peel, a series of treatments may be required to achieve desired results.

Salicylic acid which is used commonly is a Beta hydroxy acid (lipid based) used in chemical peels, it is used in acne products and used to treat acne.Salicylic acid is more potent than glycolic acid, so it provides a slightly deeper chemical peel with longer lasting results. Because beta hydroxy acid chemical peels are also considered mild resurfacing treatments, no anesthesia is needed and the recovery time after the procedure is relatively short.

Trichloroacetic acid is the most common ingredient found in medium chemical peels and come in different strengths. This substance can successfully treat a host of skin imperfections, including sun damage, fine lines and wrinkles, and acne scarring. The procedure offers effective results with minimum risk. TCA chemical peels usually take about a week to recover from, and the results are much more dramatic than lighter peels can offer. Some patients need more than one treatment session to achieve desired results.

Phenol is the substance of choice for deep chemical peels that provide the greatest and most dramatic results. This type of chemical peel may be used to remove precancerous growths or completely diminish deep wrinkles. Because the formula works more deeply than other types of chemical peels, most phenol peels require an hour or two in the doctor’s office or under anesthesia which usually involve pain medication afterward. Phenol peels can take up to a month to recover from completely, but the result is impressively smoother skin that will last much longer than that treated with other types of peels and now has been substituted with resurfacing lasers.

References

Alpha hydroxy acid facial treatments. Alpha hydroxy acid facial treatments | DermNet NZ. https://dermnetnz.org/topics/alpha-hydroxy-acid-facial-treatments#:~:text=Alpha%20hydroxy%20acid%20peels%20are,skin%20and%20improving%20skin%20tone. Accessed April 20, 2022.

Chemical peels. Pure Aesthetics. https://www.pureaestheticsgainesville.com/chemical-peels/#:~:text=Beta%20Hydroxy%20Acid%20Peels%20(salicylic,to%20treat%20acne%2Dprone%20skin. Published May 14, 2020. Accessed April 20, 2022.

Chemical Peels

Chemical peeling is a procedure where a chemical substance is applied to the skin to destroy the epidermis with or without part of the dermis, which then leads to skin regeneration and remodeling. It is one of the most common cosmetic procedures because it can improve the quality of the skin in a short time. It is used to treat many skin conditions: melisma, ephelides, post inflammatory hyperpigmentation, photoaging, undereye circles, acne vulgaris, rosacea and scars.

Chemical peels are usually classified based on their depth of skin penetration into superficial, medium and deep. Superficial peels act on the epidermis, without penetrating any deeper into the basement membrane. They are indicated for photoaging (roughness, yellow stains, fine lines, keratosis, solar lentigines), pigmentary disorders (melasma, post inflammatory hyperpigmentation), retentional acne and comedone extraction. They are usually AHA (a-hydroxy acids), BHA (b-hydroxy acids), TCA (trichloroacetic acid) 10-35%, Jessner solution and tretinoin. AHA consists of glycolic acid, lactic acid and mandelic acid, whereas BHA consists of salicylic acid. Jessner solution is a combination of resorcinol, salicylic acid and lactic acid in 95% ethanol. Combining Jessner solution and TCA 35% may add up to the synergistic effect of a medium peel. Medium peels act on the epidermis, papillary dermis, and can penetrate to the upper reticular dermis. They are indicated for photoaging (fine lines, wrinkles), pigmentary disorders, and superficial atrophic scars. They are TCA 35-50% and pyruvic acid 40-70%. The downtime is usually about one week. Deep peels eliminate the epidermis and penetrate to the mid reticular dermis. They are indicated for severe photoaging, pigmentary disorders and scars. They are TCA > 50% and phenol 88%. The downtime is about 10 days.

Most chemical peeling procedures follow a sequence of steps. There is the pre-peeling preparation (priming), pretreatment, treatment, and post-peeling care. Priming helps prepare the skin for the peeling process and for the following regeneration phase. Usually, tretinoin is applied for one month beforehand to facilitate a more homogenous penetration of the peel and to accelerate the healing process. In case of intolerance with tretinoin, it can be replaced with AHA. Sunscreen should also be used daily to prevent post-inflammatory hyperpigmentation. In dark skin individuals, an additional treatment with hydroquinone may be required. Pre-treatment is the cleaning step directly prior to the application of the chemical peel substance. The skin has to be cleansed thoroughly to remove fats, oils and debris. This allows for a homogenous penetration of the peel and a uniform result. Treatment is the application of the peeling agent. The time depends on the depth of the peel and the agent used. Treatment can involve the entire face or only part of the face. At the end, a hydrating or healing cream is applied. Sometimes, bandages may also be used with medium or deep peels. Post-peel care treatment consists of hydration and sunscreen.

Chemical peels can lead to complications. The deeper the chemical peel, the more therapeutic effects but also the more risks. Certain populations are more vulnerable to complications, such as dark skin individuals with a known history of scar formation. Therefore, it is important to adhere to pre and post peel care instructions. Complications of chemical peeling can be immediate or delayed. Immediate complications can happen in minutes to hours and include skin edema, burning, itching and blistering. Delayed complications happen in days to weeks and include hyperpigmentation, hypopigmentation, depigmentation, demarcation lines, rashes, and infections. There are also complications with medium to deep peels such as atrophic scars, cardiac arrhythmias, laryngeal edema, exacerbation of a dermatosis and infectious toxic shock syndrome.

References

1. Castillo DE, Keri JE. Chemical peels in the treatment of acne: patient selection and perspectives. Clin Cosmet Investig Dermatol. 2018;11:365-372. Published 2018 Jul 16. doi:10.2147/CCID.S137788

2. Fischer TC, Perosino E, Poli F, Viera MS, Dreno B; Cosmetic Dermatology European Expert Group. Chemical peels in aesthetic dermatology: an update 2009. J Eur Acad Dermatol Venereol. 2010;24(3):281-292. doi:10.1111/j.1468-3083.2009.03409.x

3. Samargandy S, Raggio BS. Skin Resurfacing Chemical Peels. In: StatPearls. Treasure Island (FL): StatPearls Publishing; July 25, 2021.

4. Truchuelo M, Cerdá P, Fernández LF. Chemical Peeling: A Useful Tool in the Office. Peeling químico, una herramienta útil en la consulta. Actas Dermosifiliogr. 2017;108(4):315-322. doi:10.1016/j.ad.2016.09.014

Chemical Peels

Written by: Hillary Pham and Jae Chang

Over many years, chemical peels have evolved as a technique to enhance and improve the appearance of the skin. The facial skin is the most commonly treated area of the entire skin organ for chemical peels. By doing such treatments can enhance the surface of the skin. Chemical peels treatment can improve facial scarring, uneven texture, discoloration, wrinkles, and any other kind of imperfections. This is why chemical peels have slowly emerged as a common, popular facial improvement technique.

So, what exactly does a chemical peel do? Chemical peels treatment can be done to nearly any part of the body. However, it is most commonly done on the face, neck, and hands. The treatment essentially includes chemicals that can penetrate deep into the skin and peels away the outermost layer of the skin, to ultimately reveal a more youthful looking skin underneath. Patients are more inclined to participate in this facial treatment as it results in a fresh-face appearance. There are many different kinds of chemicals that can be used during a chemical peel. For instance, chemicals like retinol, lactic acid, glycolic acid, and trichloroacetic acid. All these kinds of chemicals are different on their own but still contribute to a clean, fresh face appearance.

Trichloroacetic acid, or TCA, is an example of a chemical that can be used during a chemical peel session. In a study that was done, a glycolic and a TCA treatment were applied to the facial skin of participants. The glycolic acid treatment, itself, is a very common chemical that is found in a lot of facial skin care treatments, that is generally safe to use when applied properly. In the study, participants applied 70% glycolic acid to the entirety of the face and diluted the solution down with water after 2 minutes. Shortly after, 35% of TCA was applied to the same regions of the face, where the glycolic acid was first applied. Researchers conducted biopsies on patients at 24 hours, 39 days, 60 days, and 90 days. The researchers determine, based on the biopsies, that both the glycolic-TCA treatment resulted in a medium depth injury. By doing so, there was histological improvement in the skin pigmentation and scarring of participant’s facial skin. (III, W.P.C. et. al).

Another example of chemicals that can be used for chemical peel is tretinoin. This treatment is known as tretinoin peel or retinoic acid peel, and it offers superficial (epidermal granular layer to the epidermal basal layer) peeling, often performed in dermatological clinics in Brazil. A 2001 study included 15 participants who were followed to investigate the clinical and histologic modifications of the skin after 5 sessions of tretinoin peeling. The procedure for tretinoin peeling included receiving the procedure twice a month in tretinoin concentrations of 1-5%. The results showed that when the peel was applied to the skin for 6-8 hours, lightening of melasma in photoaged skin was quickly achieved over 2.5 weeks. It has been found that topical retinoic acid applied daily to the skin causes dispersion of melanin; therefore, tretinoin peel produces the same effects as topical retinoic acid except with the advantage of being faster and less cumbersome for patients with melasma.

Although chemical peeling is a procedure done to exfoliate the skin to cause skin rejuvenation, rare complications including persistent erythema, milia and scarring may occur. Pain and burning may occur after peel procedure in patients with sensitive skin and may persist up to 2-5 days until new skin has been generated. Treatment options include immediate application of ice to the affected area, topical calamine lotion, emollients, sunscreens, and topical steroids. Persistent erythema is an alarming sign that is a predictor of potential scarring. Normally, erythema may disappear in 3-5 days in superficial peal, 15-30 days in medium peel, and 60-90 days in deep peel. Treatments for persistent erythema include steroids and pulsed dye laser. Edema is more common in medium and deep peels; it usually occurs within 24-72 hours of chemical peeling. Although edema subsides spontaneously, affected individuals may apply ice or start on a short course of systemic steroids.

It is clear as to why the chemical peel technique has gained such popularity over the years. For a treatment that can be done under an hour, it can reveal a youthful-looking skin for numerous patients. However, individuals looking to receive chemical peels should be aware of the potential side effects that may come with the procedure.

References: III, W. P. C., & Futrell, J. M. (1994). The glycolic acid trichloroacetic acid peel. The Journal of dermatologic surgery and oncology, 20(1), 76-80.

Sumita, J. M., Leonardi, G. R., & Bagatin, E. (2017). Tretinoin peel: a critical view. Anais brasileiros de dermatologia, 92(3), 363–366. https://doi.org/10.1590/abd1806-4841.201755325

Nikalji, N., Godse, K., Sakhiya, J., Patil, S., & Nadkarni, N. (2012). Complications of medium depth and deep chemical peels. Journal of cutaneous and aesthetic surgery, 5(4), 254–260. https://doi.org/10.4103/0974-2077.104913

The purpose of chemical peels is to exfoliate the skin while creating a wound that will eventually undergo re-epithelialization. Re-epithelialization is essential for wound healing in order to close the wound. In re-epithelialization there is formation of new epithelium along with skin appendages by proliferation, migration, differentiation of keratinocytes and reconstitution of underlying dermal structures. Keratinocytes are a cellular component of the epidermis and derived from epithelial stem cells (EpSCs). In re-epithelialization, keratinocytes migrate to the wound in the epidermis then fibroblasts close the wound by migrating beneath the wound site to close the wound.

Chemical peels have three categories that are superficial, medium-depth, and deep-peeling agents. Superficial peels include salicylic acid (SA), glycolic acid (GA), lactic acid (LA), lipohydroxy acid (LHA) 5%-10%, and trichloroacetic acid (TCA) 10%-30% that usually infiltrate the stratum corneum. Medium-depth peels include TCA 35%-50%, Jessner’s solution with TCA 35%, GA 70% with TCA 35%, and phenol 88% that infiltrate the upper reticular dermis. Deep chemical peels include the Baker Gordon phenol solution that infiltrate the midreticular dermis.

Chemical peels are one of the most common nonsurgical cosmetic procedures done in the USA in order to treat pigmentation disorders such as those seen in darker skinned patients. In terms of which chemical peeling agents are appropriate for use, the choice of agent should involve previously established safety and efficacy profiles. Before starting treatment with GA, a skin test must be performed for safety purposes. Prior to treating pigmentation disorders, pre/post-treatment hyperpigmentation therapy is required. This process involves treating affected areas with azelaic acid or hydroquinone one month before & after peeling treatment. Contraindications for chemical peeling include atopic dermatitis, salicylate allergies, inflammatory rosacea, active herpes infection, isotretinoin use, and sunburnt/wounded/sensitive skin.

GA belongs to the family of naturally occurring a-hydroxy acids (AHAs). Other AHA peeling agents include lactic acid, phytic acid, and pyruvic acid. AHA peels are used to treat various skin issues such as acne, hyperpigmentation, melasma, and photodamage (skin damage due to solar UV radiation). Chemical peels are known to effectively treat post-inflammatory hyperpigmentation by removing excess pigment from the skin, peels for this condition are performed monthly. Chemical peels will also remove excess epidermal pigment in epidermal melasma/mixed melasma through a controlled chemical burn; however deep chemical peels to treat deep melasma may cause scarring.

AHA peels will improve skin issues by increasing collagen synthesis in the dermis, thinning the stratum corneum, diminishing intercellular bonding, and promoting epidermolysis. GA is used in superficial and medium depth peels with concentrations 30% to 70%, a 70% GA gel formulation provides skin benefits with a low chance of scarring. On darker skinned patients with acne a partially buffered GA solution 30%-50% is recommended, placed on skin for 2 to 4 minutes then rinsed. Peeling treatment processes involve 50%-70% GA solution, 20%-30% SA solution or TCA 10%-50% is applied with applicators to the skin for 3 to 5 minutes then neutralized and rinsed off. TCA peels should be done cautiously in darker skinned patients and should be initiated in low concentrations. Lactic acid is an option for darker skinned patients who suffer from melasma and acne scarring.

Salicylic acid (SA) is a part of B-hydroxy acids naturally found in willow bark, and SA 3%-5% is an effective keratolytic agent that improves infiltration of peeling agents. SA is recommended for PIH treatment due to its anti-inflammatory properties, as well as acne due to its comedolytic mechanism of action. Other SAs include lipohydroxy acid which modifies the stratum corneum by thinning it and improving its flexibility which lessens wrinkles. Lipohydroxy acid has an improved keratolytic effect along with antibacterial/antifungal properties and are proven safe in darker skinned patients. SA peels are commonly used for acne and oily skin, treatment involves 20%-30% solution applied to skin with applicator targeting pustules/papules for 4 to 5 minutes.

Follow-up care process involves patients to wash skin with gentle cleansers, application of emollients twice daily, and daily use of sunscreen with a minimum SPF of 30. Regarding skin pigmentation treatments, a rest period of 3 to 6 weeks is required between superficial peels.

1. Callender VD, Young CM, Kindred C. Chemical Peels, Microdermabrasion, Hair Transplantation, and Sclerotherapy. In: Kelly A, Taylor SC, Lim HW, Serrano A. eds. Taylor and Kelly's Dermatology for Skin of Color, 2e. McGraw-Hill; Accessed May 25, 2021. https://accessmedicine-mhmedical-com.jerome.stjohns.edu/content.aspx?bookid=2585&sectionid=211769065

2. Chen D, Hao H, Fu X, Han W. Insight into Reepithelialization: How Do Mesenchymal Stem Cells Perform?. Stem Cells Int. 2016;2016:6120173.

Chemical peels are also known as chemexfoliation, which is “cutaneous ablation” are generally for cosmetic purposes. As noted by source 1, the goal of a chemical peel is to remove a predictable, uniform thickness of damaged skin, which subsequently allows for normal wound healing and skin rejuvenation to occur, while simultaneously minimizing complications, such as scarring and unwanted pigmentary change.

Source 1: The caustic agents used for chemical peels cause controlled keratocoagulation and denaturation of the proteins within the epidermis and dermis, resulting in the release of proinflammatory cytokines and chemokines. Such targeted inflammation activates the normal healing signal cascade, including stimulation, development and deposition of new dermal collagen and elastin, reorganization of structural scaffold proteins and dermal connective tissue, and regeneration of new keratinocytes. This results in rejuvenation and thickening of the epidermis and an increase in dermal volume. Simultaneously, the keratocoagulation and subsequent exfoliation result in improvement in superficial and medium-depth dyspigmentation. While there might be subtle variability between the types of chemical agents used and their intended cosmetic outcome (i.e., reduction of redness vs. dyspigmentation vs. scarring), the general goal of a chemical peel is to improve the clinical appearance of skin by decreasing the quantity and quality of rhytides and/or acne scars, reducing inflammatory and noninflammatory acne lesions, improving dyspigmentation, and producing an overall more youthful appearance.

Weighing the pros and cons however, there are potential side effects which include post-inflammatory pigmentary alterations, erythema, pruritus, burning, superficial desquamation/epidermolysis in just superficial tissue injury. In medium tissue injury, side effects may include post-inflammatory pigmentary alterations, superficial bacterial or fungal infection, reactivation of HSV, scarring, milia, acneiform eruption, greater thickness desquamation/epidermolysis while deep tissue injury includes all of the above in addition to cardiotoxicity/arrthymia due to systemic absorption of phenol which was seen in 35-50% of patients, as well as hepatotoxicity, and nephrotoxicity.

1. A practical approach to chemical peels – a review of fundamentals and step by step algorithmic protocol for treatment, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6122508/

2. Chemical peels: a review of current practice, https://pubmed.ncbi.nlm.nih.gov/29064096/

A chemical peel is a procedure that can be done professionally or at home to treat skin issues such as hyperpigmentation, skin texture, acne, shallow wrinkles, melasma, photoaging, scars, and rosacea. The procedure involves applying a chemical that destroys the top layers of the skin for exfoliation and removal of superficial lesions, followed by the natural regeneration of new epidermal and dermal layers. Deeper chemical peels may reach the dermis that is underneath the epidermis, but superficial peels typically only affect the epidermis. Superficial peels use chemicals like alpha hydroxy acids (glycolic acid, lactic acid, malic acid, citric acid, tartaric acid, mandelic acid, benzilic acid), salicylic acid (a beta hydroxy acid), and/or tretinoin. Medium and deep peels use trichloroacetic acid (TCA), phenol, pyruvic acid, or the same chemicals as superficial peels but at higher concentrations. Alpha hydroxy acids cause corneolysis at low concentrations and induce epidermolysis at high concentrations. Jessner solution is a combination of resorcinol, lactic acid, salicylic acid, and ethanol, that induces corneolysis and increases the effects of other keratolytic agents. TCA has a keratolytic effect and causes coagulative necrosis of dermal and epidermal proteins. Chemical peels can also induce collagen and elastin synthesis. Repeated treatments are usually needed to see significant results, but many patients report seeing skin improvements after just one treatment. Sunscreen and a good moisturizer are important components of aftercare for chemical peels because the new skin that regenerates needs to be protected from damage or else the benefits from the chemical peel may be reversed. Chemical peels may also be associated with side effects like irritation, dryness, peeling, hyperpigmentation, infection, erythema, burning sensation, pruritus, and photosensitivity. While home chemical peels are formulated to not be as irritating to the skin, consumers must follow the directions carefully to minimize possible skin damage. When done professionally by a dermatologist or licensed esthetician, they must take into consideration the type of acid to be used, concentration, contact time, skin type, and medical history in order to maximize the efficacy of the chemical peel and minimize negative reactions.

Works Cited:

1. Sarkar R, Bansal S, Garg VK. Chemical peels for melasma in dark-skinned patients. J Cutan Aesthet Surg 2012;5:247-53

2. Truchuelo M, Cerdá P, Fernández LF. Chemical Peeling: A Useful Tool in the Office. Peeling químico, una herramienta útil en la consulta. Actas Dermosifiliogr. 2017;108(4):315-322. doi:10.1016/j.ad.2016.09.014

Alpha hydroxy acids are a common chemical utilized in the skin-peeling process; after a certain amount of time, sun-damage and aging can result in a loss of elasticity within the skin. Fine lines, wrinkles, and sagging skin may occur due to the wear and tear that the skin had been subjected to. Hydroxy acid products have a chemical niche in treating skin texture by reducing roughness over the course of months through continued use. In addition, hydroxy acid peels can be used to aid in the restoration of skin discoloration that come as a result of prolonged UV exposure. However, for patients who may struggle with acne over sun-damage, dark spots, or discoloration, glycolic acids may be the best option for a chemical peel. The mechanism behind the benefits of hydroxy acids lie in the fact that these chemicals are able to act as accelerators for the skin cycle process. This, in turn, allows for the facilitated exfoliation of dead skin cells by helping the damaged cells flake off more readily.

Glycolic acid peels are one of the quickest forms of chemical peels; unlike other kinds of chemical peels using hydroxy acids, glycolic acid peels leave far less redness upon completion, providing a benefit to patients who do not wish to show residual consequences. Glycolic acid peels have been shown through research to promote & stimulate collagen growth, helping in the prevention and healing of fine lines and wrinkles. Glycolic acid peels only take a few minutes to complete and their relative ease is what makes them an attractive and feasible option for patients who are on the go.

Salicylic acid peels are another common chemical peel that is available; unlike other hydroxy acids, salicylic acid is one of the only beta-hydroxy acids that is usable for skincare. Over the counter salicylic acid peels are diluted in concentration, diminishing the efficacy. However, at a scheduled doctor’s office visit for a salicylic acid peel, the concentration can be 20% or higher. Salicylic acid has a strong anti-inflammatory property, as well, making it beneficial for patients who may be dealing with skin redness from inflammation.

While the benefits of hydroxy acid chemical peels cannot be ignored, the consequences of continuous therapy must be assessed. Research has shown that prolonged chemical peel treatment can lead to heightened photosensitivity in patients who are exposed to UV sunlight. Studies have shown that upon complete discontinuation of chemical peel therapy that the effects of photosensitivity displayed a total reversal. However, after much debate, chemical peels were approved for safe use as alpha hydroxy acids were not shown to display a connection to carcinogenic or mutagenic activity. Hydroxy acid chemical peels were not deemed to be skin sensitizers nor were they associated with any sort of developmental or reproductive harm.

In conclusion, hydroxy acid chemical peels are a revolutionary method of skincare to help mitigate the damage of sunlight as well as to remedy the fine-lines and inflammation that a person may be experiencing. While chemical peel therapy may induce photosensitivity, its safety and efficacy has been proven and the benefits are indisputable.

Resources:

https://dermnetnz.org/topics/alpha-hydroxy-acid-facial-treatments/

https://derm.net/2018/12/hydroxy-acid-chemical-peel/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3047947/

Hydroxy acids have been used in chemical peels as a way to to help skin conditions such as keratoses, acne, age spots, wrinkles, sun-damaged skin, and so forth. Chemical peels are more often recommended in those that have fair skin, this doesn’t necessarily mean that dark skinned people shouldn’t get chemical peels only that afterwards there might be the appearance of uneven skin-tones.

There are 3 main types of chemical peels: Superficial peels, medium peels and deep peels. The superficial peels are the ones that use hydroxy acids, such as AHA and BHA. The medium peels use trichloroacetic acid; it has the ability to penetrate almost 5 layers of the epidermis to the papillary layer. The deep peels uses phenol, it produces the most dramatic results because it is able to penetrate all the way into the reticular layer of the dermis. The dangerous thing about this deep peel is that it can leave your skin permanently bleached.

The use of AHAs, in some patients, can lead to swelling, burning, etc. AHAs include glycolic acid, citric acid, malic acid, and lactic acid these acids are often applied as superficial and medium depth peels that are able to help to “treat”/reduce the appearance of the skin conditions mentioned before. For example AHAs can help reduce wrinkles by increasing the amount of glycosaminoglycan produced in the skins layers.

When used on the skin the different concentrations of AHAs can have therapeutic benefits and can help prevent DNA breakage, especially in cases of skin damage as a result of UVB radiation. Low concentrations can be used to benefit the skin, whereas higher concentrations may lead to irritation. UV radiation can cause multiple responses on the skin such as ROS accumulation, cell apoptosis and DNA damage. In the study linked below it was found that glycolic acid, a form of AHA used in chemical peels, was actually able prevent the UVB induced loss of skin cell viability and ROS formation, further pharmacology can be reviewed within the article itself.

Now glycolic acid may be the most commonly used because it penetrated the deepest, but it’s the not the only one that is used. Lactic acid peels are used on patients that have sensitive skin because it is more gentle on the skin. Salicylic acid peels are able to exfoliate and control oil production, so it is a better option for those just trying to treat breakouts. These 3 are the most superficial peels. The TCA peel is used to exfoliate and renew the skin, its good for those that want to spot treat their problematic areas. The retinol peel is a form of vitamin A that is used for deeper penetration and helps to unclog your pores. Vitamin C peels are used against free radicals on the skin that cause the skin to lose elasticity.

The one thing that has to be noted is that the deeper the peel the longer the healing time and so you want to minimize the amount sun exposure and protect your skin by using physical, broad spectrum sunscreen.

https://beautymadesimply.com/peel-so-good-understanding-the-different-types-of-chemical-peels/

https://artofdermatology.com/find-perfect-facial-peel-3-main-types/

https://www.mdpi.com/1420-3049/23/4/863/htm

https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1473-2165.2011.00566.x

Alpha hydroxy acids are a group of organic carboxylic compounds that include glycolic acid, citric acid, lactic acid, malic acid, and tartar acid. These different acids used in chemical peels are often used to rejuvenate the skin and provide a fresh look that leaves the skin looking healthy. Alpha hydroxy acid preparations have shown to reduce the signs of aging, fine lines, brown marks and dry spots. Glycolic acid may also help patients who have struggled with acne or are more prone to getting adult acne. Sun exposure overtime can result in a slower rate which old cells leave the surface of facial skin and slow the rate which new cells replace them. This layer of old cells on the skin of the face result in an appearance of aged skin and wrinkles. This glycolic peel works by dissolving the bonds that hold the dull, dead skin cells together, allowing them to peel off gently after the procedure . Alpha hydroxy acids encourage the shedding of old, sun damaged skin , and give the patients who received a chemical peel a healthier, fresher look.

Glycolic acid is the most popular and time-tested superficial peeling agent , and it is an AHA derived from sugar cane. It's the smallest and simplest in terms of chemical structure , but it is also highly hydrophilic and bioavailable. When used properly on the patient skin, exfoliation with glycolic acid and concentrations of 30 to 50% have demonstrated the best clinical results in improvement of hyperpigmentation and aging. Additionally, glycolic acid is also considered the first line treatment of choice for the treatment of melasma. For neutralization of the glycolic acid reaction , clinicians can use an alkaline neutralizing agent to finish off the procedure. The neutralizing process of the acid with the base is the reason for an increased sensation and warmth, burning or stinging that comes along with the procedure.

During the initial steps of the AHA peel, a light layer of the acid is applied to the skin and left on for a short period of time. The peel is neutralized and removed, and the peeling process of the skin begins. The chemicals cause a reaction with the skin and dissolve the top layer of the skin , so some skin peeling is expected and totally normal after the procedure. Depending on the strength of the acid used, peeling can occur anywhere from 5-7 days after the procedure. However not every single glycolic peel will result in shedding of the skin. There are many different strengths of glycolic acid used depending on how sensitive or rough the facial skin of the patient may be. A glycolic peel is not painful or unbearable and there shouldn't be any discomfort during the days of the peeling. Some people’s skin gets a little bit pink during and after the procedure, and for about a week after. It is important to avoid using heavy makeup and harsh chemicals on your skin after the procedure to avoid irritation.

Soleymani, Teo et al. “A Practical Approach to Chemical Peels: A Review of Fundamentals and Step-by-step Algorithmic Protocol for Treatment.” The Journal of clinical and aesthetic dermatology vol. 11,8 (2018): 21-28.

Salicylic acid, which comes from the willow bark tree, has been used for thousands of years to treat a wide range of ailments. One of the ailments salicylic acid treats is its ability to improve skin conditions in patients with acne and other conditions. The ability of salicylic acid to exfoliate the skin makes it a good agent for conditions that improve with peeling of the skin. In particular, the ability of salicylic acid to induce skin peeling makes it a useful peeling agent for patients with acne. Induced peeling of the skin is a safe, efficacious, and cost-effective procedure for treating various skin disorders and to smooth out the skin. The principle of peeling involves controlled chemical injury to the skin in order to prompt it to rejuvenate, leading to smoothening of the skin and improvement of its surface texture. Chemical peels can be classified in the 3 different ways via the level of injury caused to the skin. These three categories are superficial, medium-depth, and deep. This property of salicylic acid allows it to treat a wide variety of skin conditions such as acne vulgaris. This study investigates the safety and efficacy of a topical salicylic acid 1.5% cream for treatment of facial acne. A total of 20 patients with facial acne were enrolled. Patients were treated with topical 1.5% salicylic acid cream and instructed to apply the cream over the affected area twice daily (in the morning and evening) for 4 weeks. In all, 95% of patients improved: 20% had complete clearing, 30% had significantly improved, 15% had moderate improvement, 30% had mild improvement, and there was no response in 5% of the patients. This study shows that salicylic acid is efficacious and has an important role when dealing with acne. Salicylic acid can also be used in patients instead of antimicrobial treatments in order to reduce increasing antimicrobial resistance in pathogens.

References

Arif T. Salicylic acid as a peeling agent: a comprehensive review. Clin Cosmet Investig Dermatol. 2015;8:455-61.

Zheng Y, Wan M, Chen H, et al. Clinical evidence on the efficacy and safety of an antioxidant optimized 1.5% salicylic acid (SA) cream in the treatment of facial acne: an open, baseline-controlled clinical study. Skin Res Technol. 2013;19(2):125-30.

Salicylic acid is a popular skincare ingredient that can be used as a peeling agent to treat various skin disorders including acne, melasma, photodamage, hyperpigmentation, etc. It is a member of the hydroxy acids. Salicylic acid can come from natural sources such as willow bark and wintergreen leaves or it can be synthesized artificially. Chemical peels can be classified as superficial, medium-dept and deep. Chemical peeling is when a chemical peeling agent is applied to the skin, causing controlled chemical injury and exfoliation of the superficial layer. This leads to regeneration and rejuvenation of new epidermal tissue. Salicylic acid disrupts cellular junction and softens the stratum corneum. It can also decrease sebum secretion in patients. Since it is a salicylate, it has anti-inflammatory properties. Contraindication for salicylic acid peeling includes active infection, pregnancy, tanned skin, skin malignancy, etc. A 20% to 30% salicylic acid formulation in an ethanol base is used for chemical peeling and repeated every 2 to 4 weeks. The face is cleansed with alcohol, the peel is applied and left on for 3-5 minutes and then rinsed off using tap water. Some side effects from this procedure include dryness and crusting.

Lipohydroxy acid is a derivative of salicylic acid. It is more lipophilic due to a higher molecular weight and added fatty chain resulting in less skin penetration. Lipohydroxy acid was found to stimulate the production of glycosaminoglycans, collagen and elastin, causing dermal thickening.  A study compared lipohydroxy acid to benzoyl peroxide in treating acne and they had similar efficacy. Lipohydroxy acid can be an option for patients intolerant of benzoyl peroxide. 

References

Arif T. Salicylic acid as a peeling agent: a comprehensive review. Clin Cosmet Investig Dermatol. 2015;8:455-461. Published 2015 Aug 26. doi:10.2147/CCID.S84765

Zeichner JA. The Use of Lipohydroxy Acid in Skin Care and Acne Treatment. J Clin Aesthet Dermatol. 2016;9(11):40-43.

Chemical peels are used to treat multiple skin conditions pertaining to the face such as wrinkles, acne, skin discoloration and scars. A chemical peel is a procedure that uses chemical solutions to remove the top layers of the skin and reveal a smoother and younger looking layers. There are three intensity levels of chemical peels: light, medium, and deep. A light chemical peel removes the outer layer of the epidermis and is typically used to treat fine wrinkles, acne, uneven skin tone and dryness. This can be done as often as every two to five weeks depending on desired results and is typically safe for all skin types. Healing time is three to five days. Medium chemical peels remove skin from the epidermis and upper portions of the dermis. These are typically done to treat wrinkles, acne scars and uneven skin tone and can be repeated after three to nine months to maintain results. Healing time is about one month and sun protection is needed for several weeks following the procedure. Deep chemical peels remove skin cells from the epidermis and portions of the mid to lower layer of the dermis. These peels cause the breakdown of keratin and other proteins in the dermis and most effectively stimulate collagen production. The procedure may be recommended in those who have deeper wrinkles, scars or precancerous growths and can only be performed once. Sun protection is always required on the treated skin with a healing time of more than 2 months.

The most common keratolytic agents include glycolic acid, salicylic acid and Jessner’s solution. Glycolic acid is a hydrophilic agent and is the most common alpha-hydroxy acid used for chemical peels. Unlike salicylic acid and Jessner’s solution, application of a neutralizing agent such as sodium bicarbonate is required to cease the action of glycolic acid on the skin. Salicylic acid is more lipophilic than glycolic acid allowing it to better penetrate through the skin’s lipid layer and is the reason for its use in acne treatment. Jessner’s solution contains 14% resorcinol, 14% salicylic acid, and 14% lactic acid mixed in ethanol. Primary indications include acne and hyperkeratotic disorders due to its strong keratolytic effects. Other keratolytic peeking agents include mandelic acid (an alpha-hydroxy acid), the combination of 20% salicylic acid and 10% mandelic acid, lactic acid (a beta-hydroxy acid), pyruvic acid (an alpha-keto acid), retinoic acid, and resorcinol.

• Uptodate. 2020. Chemical peels: Principles, peeling agents, and pretreatment assessment. [online] Available at: <https://www-uptodate-com.jerome.stjohns.edu/contents/chemical-peels-principles-peeling-agents-and-pretreatment-assessment?search=Role%20of%20 Hydroxyacids%20in%20Chemical%20Peels&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1> [Accessed 28 May 2020].

The presentation focuses on the role of hydroxy acids in chemical peels. Chemical peels have become an important part of cosmetic practices. They are an affordable procedure that brings significant results in treating certain skin conditions. Peels are based on the idea of rejuvenating the skin by first damaging it and removing the keratin layer of dead skin, which then stimulates the production of healthy new skin cells. Skin peels are categorized based on their level of penetration: superficial peels, medium peels, and deep peels. Deciding the type of peel to use depends on the skin condition being treated. Common uses include acne, photodamage, actinic keratosis, pigmentary disorders, scars, etc.

Superficial peels penetrate the epidermis, decreasing corneocyte adhesion and increasing dermal collagen. Epidermal regeneration typically occurs within 3-5 days. Medium peels penetrate into the papillary dermis, and deep peels penetrate into the reticular dermis. Both require longer healing times.

Superficial peels are milder peels, most suitable for those with mild sun damage with pigmentation, mild acne scarring, dry skin, or fine wrinkles. They tend to be made from alpha or beta hydroxy acids (AHAs and BHAs). AHAs are derived from milk and fruit sugars. The most commonly used are glycolic and lactic acid. Both penetrate the skin well and have been shown to be very effective. BHAs tend to be less commonly used than AHAs. A well-known BHA is salicylic acid, which is most useful for oily skin and treating acne.

Medium peels include combination formulations that also contain hydroxy acids. Different blends are available, such as trichloroacetic acid with glycolic, lactic, or salicylic acid.

Chemical peels, especial superficial ones, are generally well tolerated. Adverse effects mostly consist of irritation of the skin. Protection from the sun is important during the healing process. Sunscreen with at least SPF 30 should be applied daily and direct sunlight should be avoided.

Reference:

Smith V. An overview of chemical peels. The PMFA Journal. https://www.thepmfajournal.com/features/post/an-overview-of-chemical-peels. Published September 2016. Accessed May 28, 2020.

Chemical peels come in various different levels such as superficial peels, medium peels, and deep peels. The purpose of these chemical peels are to damage the skin which will help stimulate new cell growth. Superficial peels penetrate the epidermis and skin regenerates within 3-5 days and can be used for acne, actinic keratosis. Medium peels penetrate the papillary dermis and take a longer time to heel (1 week or more). This also requires sun penetration, especially for the darker skin since it can lead to hyper pigmentation. They can be used for Actinic keratosis, pigmentation disorder. Deep peels penetrate to the deepest layer. It is the most effective in stimulating collagen production. It takes the longest healing time (over 2 months). It's more commonly used for scars, deep wrinkles, etc. Some superficial peel agents are alpha and beta hydroxy acids, tretinoin. Glycolic acid can be used for acne, wrinkles, and photoaging.Glycolic peels are chemical exfoliants, and they remove all the dead skin cells laying on top of the skin’s surface. This helps to reveal healthier skin underneath and allow the skin to glow and show a youthful complexion. Another agent that is used is Lactic Acid which helps smooth wrinkles, improves skin tones and helps with clearing pores. Salicylic acid is one of the most common skin products used and it's more lipophilic in nature. This helps with penetrating the oil glands which helps with acne. It’s used for warts, acne, keratosis, etc. Other products can also be used such as citric acid, lactobionic acid, however they aren’t as commonly used.

Reference:

F. H. Glycolic Acid Chemical Peel - Schweiger Dermatology. Schweiger Dermatology Group. https://www.schweigerderm.com/glycolic-acid-peel/#. Accessed May 28, 2020.