Chemical peeling, also known as chemexfoliation or chemical exfoliation, is a procedure where a chemical substance applied to the skin causes controlled destruction of the epidermis with or without part of the dermis, leading to skin regeneration and remodeling. Chemical peels can be used to treat various skin conditions, such as acne vulgaris, photodamage, pigmentary disorders, and scars.[1] Also, dermatologists and facial plastic surgeons commonly employ a chemical peel as a therapeutic or cosmetic intervention to enhance appearance either alone or in combination with other techniques, such as laser or dermabrasion.[2][3] Chemical peels are commonly classified based on their depth of skin penetration into superficial, medium, and deep peels. The factors affecting the depth of peeling, and thus the degree of its therapeutic effects, include the properties of the chemical agent used (e.g., concentration and pH), the physician's application technique, and the patient's skin condition and sensitivity.[2]
A basic comprehension of the layers composing skin is crucial to understanding the different types of chemical peeling and its depth of action.[4] The skin consists of three layers, epidermis, dermis, and subcutaneous tissue (hypodermis).
Chemical peels are commonly classified based on their depth of skin penetration into superficial, medium, and deep peels. Superficial peels penetrate the stratum corneum of the epidermis and are further sub-classified by some authors into very light (to stratum spinosum) and light (to stratum basale). Medium peels penetrate the papillary dermis to the upper reticular dermis, while the deep peels' effect reaches the mid-reticular dermis.[5]
When performing a chemical peel, proper patient evaluation, and execution of a comprehensive treatment plan can produce safe, reliable, and satisfactory outcomes. Various indications for using chemical peeling as a technique for skin resurfacing exist, including[6][7][8][3][9]:
Contraindications to chemexfoliation include[10][11]:
The first and most important equipment required for performing chemical peeling is the actual peeling agent. Before delving into listing the various types of solutions and acids used for this purpose, a swift review of basic chemistry is necessary to understand some of the commonly used terms. One important concept is the pKa of the peeling agent, which is the pH at which 50% of the chemical is in a free acid state. When choosing the type of peel used, a lower pKa correlates with a stronger peel. Indeed, there are many types of peeling agents available.[1]
The following are examples of common agents listed with its corresponding depth of effect[5][12]:
Each agent has a slightly different mechanism of action, not within the scope of this review, but the principles are generally the same. Epidermolysis, particularly of the stratum corneum provides smoother skin. Peels that reach the basal layer containing melanocytes will improve uneven pigmentation. When peels affect the papillary or upper to the mid-reticular dermis, this aids with reducing rhytides with deposition of elastin and collagen.[5][12]
For patient safety, resuscitation equipment needs to be available in a well-ventilated procedure room. Personnel must wear gloves. Application brushes, cotton swabs, and gauze should be available as well. Cardiac monitoring must be available if using phenol, given the risk of cardiotoxicity.
A clinician trained in the application and management of skin disorders requiring chemical peeling generally performs this procedure with a nurse present to assist. An anesthesiologist must be present if using general anesthesia or a phenol peel.[5]
Before considering this procedure, obtaining informed consent is necessary. Photo documentation is encouraged after dedicated patient consent for comparison. Post-peel expectations require discussion with the patient. A complete history and physical examination must exclude any contraindications for the procedure as listed above.
The first step is choosing the appropriate depth of peel according to the patient's skin type and condition requiring treatment. One commonly used classification of skin phototypes is the Fitzpatrick classification.[13] It classifies patients into six different complexion colors/types by their reaction to sun exposure:
Generally, light or very light peels are appropriate for all Fitzpatrick skin types. The perfect patient for medium or deep chemexfoliation is a female with fair skin and blue eyes (i.e., Fitzpatrick I). Fitzpatrick III-VI patients may be prone to aberrant pigmentation or dyschromasia.[14][15]
Another way to categorize skin is by using the Glogau classification, which assesses photoaging[13]:
Special considerations in male patients are often needed as they tend to have thicker skins with less predictable peeling outcomes.[6] One way to reliably predict the result is with pre-peel spot testing, though this is not a routine process; nevertheless, some clinicians elect to perform pre-peel testing to help select the proper peel for the patient.
The clinician should perform priming should to facilitate effective peeling. Adequate priming should be started 2 to 4 weeks before the procedure and involves the application of a topical agent on the skin to thin the stratum corneum layer, which increases the depth of penetration.[11] A commonly prescribed priming agent is all-trans retinoic acid or tretinoin (0.025 to 0.05%) cream. Other options include salicylic and glycolic acids at 5 to 10% concentration. For patients susceptible to hyperpigmentation, hydroquinone (2 to 4%) cream can be utilized pre- and post- peel to decrease post-inflammatory pigmentary reactions by targeting and inhibiting tyrosinase in melanocytes. In patients with a history of herpes simplex viral infection, a course of acyclovir merits consideration, though some authors routinely prescribe prophylactic antivirals as well.[16]
The clinician must stress the importance of protection against UV rays (pre and post-treatment) to the patient. Patients are advised to avoid procedures that could traumatize the skin such as dermabrasion and waxing. On the day of the procedure, they should be instructed to cleanse their skin and not to apply any skincare or makeup products.[13]
Before starting the chemical peeling procedure, the patient's skin requires cleaning with a degreasing agent such as isopropyl alcohol or acetone for the removal of any residue or makeup.[5] They should be in a supine position with the head of the bed elevated to 45 degrees.[11] A hair cap should be worn to keep the hair away from the treatment field. The clinician can apply petroleum jelly to areas of potential pooling of the chemical such as the nasolabial folds and lateral canthi. The eyes should be covered with an appropriate shield. General anesthesia is not routinely required but may be a consideration for deep peels. Oral analgesics can be administered, such as acetaminophen.
The peeling agent can be applied on the thicker skin regions first (i.e., chin, nose, cheeks, and forehead) followed by the thinner skin regions (i.e., around the eyes and mouth). A brush, gauze, or a wooden spatula can be used to apply the chemical in evenly distributed strokes, the choice of which application method will depend on the desired effect and chemical peel used. Peel-specific application nuances exist for each type and require experience until achieving mastery. As an example, gauze sponges can be more abrasive and more suitable for liquid formulations. Overlaps in brushstroke coverage should be avoided as it may cause overconcentration of the agent and an uneven outcome. The edge of the treatment site can be feathered to blur demarcation lines.[16][2]
Certain areas requiring special attention include:
Post-application, specific agents (primarily TCA) can induce a reaction called frosting. It has three levels based on the degree of protein denaturation. In level, I frosting (superficial peel), erythema, and patchy areas of frosting occur. Level II (medium peel) represents a white coat of frosting with some erythema being visible beneath, while level III (deep peel) exists when a white plaque-like formation with almost no erythema visible.
After peel application, cool saline compresses can be applied to help neutralize the solution (glycolic acid) and/or provide patient comfort. "Vinegar soaks" using 0.25% acetic acid facilitates healing, as does the application of a non-scented, bland emollient 3 to 5 times a day to the desquamated areas after soaks. Desquamation usually concludes within several days (depending on the depth of the peel) and is followed by intense erythema which gradually subsides over 1 to 2 weeks thereafter. After 24 hours, the patient may shower and use a non-detergent face wash. Protection against sun exposure and applying sunscreen requires re-emphasis.[16] The patient should defer use of any makeup/concealer until the skin has healed.[5]
A general rule-of-thumb when thinking about the risks of chemexfoliation is that the deeper the peel correlates with increased therapeutic effects but also more significant risks.[17] Certain patients are more vulnerable to complications, including darker skin individuals with a known history of scar formation. Exposure to isotretinoin would also negatively affect peeling outcomes. As once can infer, patient selection and counseling remain pivotal to maximize results and lessen complications. Strict adherence to the pre- and post-peel care instructions, especially sun avoidance, is important to optimize results as well.[1]
Complications for chemical peeling can be classified into immediate (minutes to hours) or delayed (days to weeks):
Skin resurfacing with a chemical peel is a powerful tool that can restore a more youthful and rested appearance to the aging face. It is also used to manage other skin conditions with the aim of homogenizing pigmentation and reducing textural unevenness. Skin resurfacing with chemical peels ultimately aims to enhance a patient's appearance and thus, self-esteem.[20][21]
It remains imperative to identify the risk factors and perform a thorough assessment of the patient before performing a chemical peel. A team approach is an ideal way to limit the complications of this procedure. Before the procedure, the patient should have the following done:
an interprofessional team of aestheticians, dermatology specialty-trained nurses, and physicians should be available before, during, and after the chemical peel to maximize the best outcomes. Close follow-up during the initial post-operative period, either by a nurse and/or clinician experienced in the post-procedural care of chemical peels, should monitor the patient for possible complications ranging from local skin issues to cardiotoxicity (with deep phenol peels). It is vital for the nurse and clinician to provide coordinated education to the patient on proper maintenance of the skin after a chemical peel, and avoiding excess sun exposure for the first several weeks afterward to maximize results and prevent complications; this is where a specialized dermatology nurse can be a tremendous asset.[2]
Close communication between the team members is essential for improving outcomes following the use of chemical peels. [Level V]
Over-the-counter pain medications are generally sufficient to help with post-procedural facial discomfort. To minimize erythema and dryness, the patient should employ 0.25% acetic acid soaks as detailed above, and apply petroleum jelly several times a day until the treated area has finished peeling (5-10 days). Intense erythema appears immediately after skin desquamation, though gradually subsides over several days. Patients are strongly encouraged to avoid direct sun exposure for the first several days after the procedure. Protective measures should be exercised for the next several weeks to months, including wearing sunscreen and wide-brimmed hats when outdoors. Makeup may be worn again after about 1-2 weeks once re-epithelialization is completed and skin is in a good state.[5] Close follow up after the procedure is encouraged to assess for any complications. If desired, photographic documentation should occur at around 2-3 months postoperatively.
Close follow-up during the initial post-operative period, either by a wound care nurse and/or clinician experienced in post-procedural care of skin resurfacing with chemical peels, should monitor the patient for possible complications ranging from localized skin reactions to systemic cardiotoxicity.[5]
[1] | Rendon MI,Berson DS,Cohen JL,Roberts WE,Starker I,Wang B, Evidence and considerations in the application of chemical peels in skin disorders and aesthetic resurfacing. The Journal of clinical and aesthetic dermatology. 2010 Jul [PubMed PMID: 20725555] |
[2] | O'Connor AA,Lowe PM,Shumack S,Lim AC, Chemical peels: A review of current practice. The Australasian journal of dermatology. 2018 Aug; [PubMed PMID: 29064096] |
[3] | Sun HF,Lu HS,Sun LQ,Ping WD,Mao DS,Li D, Chemical Peeling with a Modified Phenol Formula for the Treatment of Facial Freckles on Asian Skin. Aesthetic plastic surgery. 2018 Apr; [PubMed PMID: 29279953] |
[4] | McLafferty E,Hendry C,Alistair F, The integumentary system: anatomy, physiology and function of skin. Nursing standard (Royal College of Nursing (Great Britain) : 1987). 2012 Sep 19-25; [PubMed PMID: 23248884] |
[5] | Weissler JM,Carney MJ,Carreras Tartak JA,Bensimon RH,Percec I, The Evolution of Chemical Peeling and Modern-Day Applications. Plastic and reconstructive surgery. 2017 Nov; [PubMed PMID: 29068926] |
[6] | Reserva J,Champlain A,Soon SL,Tung R, Chemical Peels: Indications and Special Considerations for the Male Patient. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 2017 Nov; [PubMed PMID: 28902026] |
[7] | Chen X,Wang S,Yang M,Li L, Chemical peels for acne vulgaris: a systematic review of randomised controlled trials. BMJ open. 2018 Apr 28 [PubMed PMID: 29705755] |
[8] | Castillo DE,Keri JE, Chemical peels in the treatment of acne: patient selection and perspectives. Clinical, cosmetic and investigational dermatology. 2018 [PubMed PMID: 30038512] |
[9] | Kaminaka C,Yamamoto Y,Yonei N,Kishioka A,Kondo T,Furukawa F, Phenol peels as a novel therapeutic approach for actinic keratosis and Bowen disease: prospective pilot trial with assessment of clinical, histologic, and immunohistochemical correlations. Journal of the American Academy of Dermatology. 2009 Apr; [PubMed PMID: 19293009] |
[10] | Nast A,Dréno B,Bettoli V,Degitz K,Erdmann R,Finlay AY,Ganceviciene R,Haedersdal M,Layton A,López-Estebaranz JL,Ochsendorf F,Oprica C,Rosumeck S,Rzany B,Sammain A,Simonart T,Veien NK,Zivković MV,Zouboulis CC,Gollnick H, European evidence-based (S3) guidelines for the treatment of acne. Journal of the European Academy of Dermatology and Venereology : JEADV. 2012 Feb [PubMed PMID: 22356611] |
[11] | Khunger N, Standard guidelines of care for chemical peels. Indian journal of dermatology, venereology and leprology. 2008 Jan; [PubMed PMID: 18688104] |
[12] | Truchuelo M,Cerdá P,Fernández LF, Chemical Peeling: A Useful Tool in the Office. Actas dermo-sifiliograficas. 2017 May [PubMed PMID: 27931952] |
[13] | Starkman SJ,Mangat DS, Chemical Peels: Deep, Medium, and Light. Facial plastic surgery : FPS. 2019 Jun [PubMed PMID: 31189196] |
[14] | Roberts WE, Chemical peeling in ethnic/dark skin. Dermatologic therapy. 2004; [PubMed PMID: 15113287] |
[15] | Al-Waiz MM,Al-Sharqi AI, Medium-depth chemical peels in the treatment of acne scars in dark-skinned individuals. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 2002 May; [PubMed PMID: 12030868] |
[16] | Lee KC,Wambier CG,Soon SL,Sterling JB,Landau M,Rullan P,Brody HJ, Basic chemical peeling: Superficial and medium-depth peels. Journal of the American Academy of Dermatology. 2019 Aug [PubMed PMID: 30550830] |
[17] | Landau M, Chemical peels. Clinics in dermatology. 2008 Mar-Apr; [PubMed PMID: 18472061] |
[18] | Costa IMC,Damasceno PS,Costa MC,Gomes KGP, Review in peeling complications. Journal of cosmetic dermatology. 2017 Sep; [PubMed PMID: 28349655] |
[19] | Monheit GD, Medium-depth chemical peels. Dermatologic clinics. 2001 Jul [PubMed PMID: 11599398] |
[20] | Kouris A,Platsidaki E,Christodoulou C,Efstathiou V,Markantoni V,Armyra K,Potouridou I,Rigopoulos D,Kontochristopoulos G, Patients' self-esteem before and after chemical peeling procedure. Journal of cosmetic and laser therapy : official publication of the European Society for Laser Dermatology. 2018 Aug; [PubMed PMID: 29286838] |
[21] | Bolton MA,Lobben I,Stern TA, The impact of body image on patient care. Primary care companion to the Journal of clinical psychiatry. 2010; [PubMed PMID: 20694111] |