CHEMICAL PEELS

📌What is meant by chemical peeling??

 Chemical peeling or chemo-exfoliation is application of one or more chemical agents of defined strength so as to cause controlled chemical burn of portion ofepidermis and / or dermis through dry desquamation or moist maceration followed by its exfoliation and subsequent regeneration of epidermis along with remodelling of collagen and elastic fibres and deposition of GAG during the repair process in dermis

📌History of chemical peels

👉Egyptians- first ones to use peels
👉Cleopatra used  sour milk (lactic acid ) for bathing!
👉French women- old wine (tartaric acid)
👉In 1882, P.G .Unna, a German Dermatologist, used salicylic acid, resorcinol, phenol and trichloroacetic acid (TCA) as peeling agents.
👉In 1976, Resnik et al. described the utility of TCA peels in various skin conditions.
👉In the late 1980s and the 1990s, α-hydroxy acids (AHAs) became available for superficial peeling.

📌Peeling agents

1.Alpha-hydroxy acids (AHA):
a. Monocarboxylic acids: Glycolic acid, lactic acid
b. Bicarboxylic acid: Malic acid
c. Tricarboxylic acid: Citric acid

2. Beta-hydroxy acids (BHA): Salicylic acid

3. Trichloroacetic acid (TCA)

4. Alpha-keto acids: Pyruvic acid

5. Resorcinol

6. Jessner’s solution

7. Retinoic acid

8. Phenol

📌Brody's classification of chemical peels

A) Superficial
i) very light (stratum granulosum)
ii) light (papillary dermis)

B) Intermediate (upper reticular dermis)

C) Deep (mid reticular dermis)

📌Mark Rubin's classification of chemical peels

A) Very superficial (stratum corneum)- exfoliation of the stratum corneum, without any epidermal necrosis.
B) Superficial (epidermal)-destruction of the full epidermis- upto basal layer
C) Medium (papillary dermal)
D) Deep (reticular dermal)

📌Mechanism of action of chemical peels

1. Metabolic action – AHA, Azelaic acid, Retinoic acid
2. Caustic action – TCA, Jessner’s solution
3. Toxic action – Phenol, SA

📌Stages of action of chemical peels

A) Coagulation & inflammation
B) Re-epithelialization
C) Granulation tissue formation
D) Angiogenesis
E) Collagen & matrix remodelling

📌Trichloroacetic acid(TCA)

📍Available as crystals- dissolved in distilled water to make a solution

📍 Prepare fresh soln. every 6 months

📍Readymade TCA peels:-
1) Obagi blue peel
2) Accupeel

📍Concentration of TCA:-
10-30% - Superficial
35- 50%- Medium depth
>50%- Deep

📍MOA- TCA coagulates proteins, which is responsible for  FROSTING→ cell death followed by necrosis and  sloughing of the skin.

📍END POINT OF TCA- FROSTING

📍Intensity of frosting → depends on depth of peel

📍Advantages of TCA:-
*Inexpensive , easily available & easy to prepare
*Stable with no systemic toxicity.
*Peel depth correlates with the intensity of the frost and the end point is easy to judge.
*No need of neutralization

📍Disadvantages OF TCA:-

📍Higher concentrations (35% and above) can cause scarring

📌Alpha hydroxy acids

📍Group of carboxylic acids with OH group in α position

📍Derived from fruits , hence called fruit acids

📍Examples :
Glycolic acid- Sugar cane
Lactic acid- Sour milk
Citric acid- Citrus fruits
Malic acid- Apple
Mandelic acid- Bitter almonds
Tartaric acid- Grapes

📍Glycolic acid

👉Most widely used AHA

👉Available as 70% stock solution- diluted with SD alcohol, propylene glycol, acetone/ plain water to get desired concentration

👉Readymade preparations- 20%, 35%, 50%, 70%

👉Neutralised by – 10-15% NaHCO3

👉Indications: Acne,melasma,PIH,freckles,photoaging

👉Important factors: concentration of free acid, contact time

👉End point depends on skin pathology & desired level of peeling

👉Used alone(superficial) or as combination with 35% TCA (MDP)
20- 35%- Very superficial
50-70%- Superficial
70%- Medium

👉MOA:-

*At low conc- ↓ keratinocyte cohesion by interfering with ionic binding→ ↑ desquamation & thinning of stratum corneum

*High conc-keratinocytes get totally detached→epidermolysis

*Dermal effects- modulates fibroblast → ↑ synthesis of collagen, elastin & deposition of GAG → improves superficial wrinkles & ↓ photoaging

*Basal keratinocyte stimulation → thickened epidermis with thinner stratum corneum→ useful in atrophic photoaged skin

*Inhibit tyrosinase →↓melanin synthesis→↓ hyperpigmentation

*Antioxidant action

*Moisturizing action

👉PROS AND CONS OF GA

✅Long shelf life

✅Well tolerated

✅No systemic toxicity

❎Expensive

❎Difficult to obtain a standardized solution

❎Difficult to judge the end point , as there is no frosting, while erythema can be hard to appreciate in dark skinned patients.

❎Neutralization is mandatory

📍Other AHAs

*LACTIC ACID- Largest molecular weight  AHA; antimicrobial, anti- inflammatory; used as a peeling agent in its full strength of 92% & pH- 3.5; mainly used as combination peel.

*MANDELIC ACID-Amygdalin,anti-seborrheic,keratolytic;30% to 50%; Bacteriostatic properties
Safe in darker skin type; infected acne

*PYRUVIC ACID: alpha ketoacid – converts to lactic acid,sebostatic,antimicrobial; 40%.

*PHYTIC ACID:antioxidant,Easy phytic peel(GA,MA,LA,PA)

*KOJIC ACID: tyrosinase inhibitor,only combination –10%

*ARGININE:20%; periorbital melanosis

*AZELAIC ACID: Malasezzia furfur is the source: antioxidant; 20%

*FERULIC ACID: antioxidant, photoaging fine lines

📌β – Hydroxy acid (BHA) : Salicylic acid

📍Hydroxy derivative of benzoic acid.

📍Derived from willow bark, wintergreen leaves & sweet birch.

📍Available as SA powder (dissolved in 95% ethanol / methanol) & as readymade peeling kits.

📍It crystallizes on face, once vehicle volatises, leaving a white coat – PSEUDO FROST.

📍10-30%; Mostly used as superficial peels

📍Additional actions of salicylic acid peels:-

1. Keratolytic and anti-inflammatory action- Acne
2. Lipophilic nature – better penetration of comedones-excellent comedolytic action
3. Self-neutralizing action
4. Superficial anaesthetic action
5. Mild antifungal action

📌Tretinoin peels

📍Tretinoin in higher concentrations (1%) → used as a peeling agent (yellow peel) for the Rx of acne, melasma and photoaging

📍Disadvantages-it is yellow in color;has to be left on for at least 4 hours.

📌Jessner's solution peel

📍Contains:-

Resorcinol - 14g
Salicylic acid -14g
Lactic acid -14g
Ethanol (95%) q.s. add 100cc

📍Modified Jessner's solution: resorcinol replaced by citric acid

📍Indications:-

1.PIGMENTARY DISORDERS
a. Melasma
b. Post-inflammatory hyperpigmentation
c. Freckles
d. Lentigenes

2. ACNE
a. Acne vulgaris- mild to moderately severe
b. Acne excoriée
c. Post-acne pigmentation
d. Post-acne scarring

3. COSMETIC
Fine wrinkling
Photoaging
Actinic damage
Dilated pores

4.EPIDERMAL GROWTHS
Seborrheic keratoses
Actinic keratoses
Warts
Milia
Sebaceous hyperplasia
Dermatoses papulosa nigra

📍Contraindications:-

1. Active infection (bacterial or herpes simplex )
2. Open wounds;
3. History of taking photosensitive drugs
4. Unreliable patient (a patient careless about avoiding sun exposure or application of medicine);
5. Unrealistic expectations
6. For medium depth and deep peels, history of abnormal scarring, atrophic skin, keloids and
isotretinoin use in the last six month

📌Factors affecting outcome of peels

📍PATIENT FACTORS – Fitzpatrick skin type, gender & occupation, indication & site of peel

📍PEELING AGENT FACTORS – MOA,strength & acidity, depth of penetration, contact time

📍TECHNIQUE – Method,no.of coats,duration,expertise

📌Before giving peels......

1. Pre peel evaluation
2. Priming
3. Test peel

📍Pre peel evaluation

1)HISTORY:-
-general medical history
-degree of sun exposure
-occupation to judge the level of sun exposure,
-history of herpes simplex
-recent isotretinoin treatment in the last six months (for medium depth and deep peels)
-Keloidal tendency , tendacy for PIH
-current medications, any previous surgical treatment
-immunocompromising conditions, and smoking (may delay healing in deep peels)
-phenol peels- history of systemic disease, especially cardiac disease

2)EXAMINATION:-
-Skin type (Fitzpatrick)
-Degree of photoaging ( Glogau)
-degree of sebaceous activity (oily or dry skin)
-presence of postinflammatory hyperpigmentation, keloid or hypertrophic scar ,infection, and preexisting inflammation
-Extent of pigmentation in melasma by Wood’s light examination : Epidermal- more accentuated, Dermal-less obvious
-Fitzpatrick types I - III are best candidates for chemical
peel
-Types IV-VI - greater risk of hyperpigmentation
-Superficial and medium depth peels safer for Indian
skins.
-Deep peels should be avoided in type IV-VI

3)DOCUMENTATION
Informed consent
Photographic record

📍Priming before peels

*Done 2-4 weeks prior to procedure

*Advantages:
☑Decreased risk of post-inflammatory hyperpigmentation

☑Reduced wound healing time

☑Facilitating uniform penetration of the peeling agent

☑Detection of intolerance of any agent likely to be used for maintenance therapy

☑Enforcing patient compliance

*Agents used for priming:

1. Tyrosinase blocking agents-Hydroquinone ( 2% or 4%), kojic acid (2%), Azelaic acid (20%)- as priming agent in pigmentary disorders
MOA- Inhibit tyrosinase- ↓ chance of PIH

2. Topical retinoids- Tretinoin ( 0.025%)
Adapalene (0.1%)
Tazarotene(0.1%)

3. Glycolic acid 6-12%
Preferred in acne & photoaging
MOA- thinning of the stratum corneum. This helps to achieve better and uniform penetration of the
peeling agent.Also,it enhance dispersion of melanin granules in the epidermis- skin lightening effect &↓ chance of PIH

📍Test peel

*1- 1.5 inch circular or square area post auricular region;2 weeks prior to peel
*To :-

☑Detect any adverse reactions

☑Make the pt familiar with the procedure

☑Use this time to prime the skin

🔍A week prior to peel, STOP…

*Face washes
*Waxing, bleaching
*Hair dyes
*Straightening Rx
*Other resurfacing/exfoliating Rx(like scrubs)

📌Dermatologist doing the peel should be ready with:-

*Correctly labelled peeling agents in various concentrations
*Alcohol to clean the skin
*Acetone to degrease the skin
*Cold water
*Syringes filled with normal saline for irrigation of the eyes, in case of accidental spillage.
*Neutralizing solutions, specific for peels
*Glass bowl or beaker in which the required agent is poured
*Head band or surgical cap for the patient
*Gloves
*Cotton-tipped applicators or swab sticks or brush
*Cotton gauze pieces
*Fan for cooling
*Timer for alpha-hydroxy acid peel

📌Safety precautions for peeling

1. Always check label on the bottle
2. Never pass an open container of acid / wet applicator over patient's face.
3. Never perform a peel with patient lying completely flat.
4. Always keep water filled syringes ready

📌Procedure of peeling

👉The patient is asked to wash the face with soap and water.

👉The hair is pulled back with a head band or surgical cap.

👉Place the patient in supine position with head elevated to 45º

👉Eyes are closed with eye pad and the ears are plugged with cotton

👉 Using gauze pieces, the skin is cleaned with spirit and then degreased with acetone.-removes residual oils, debris

👉Sensitive areas like the inner canthus of the eeye,nasolabial fold and lips are protected with
petroleum jelly

👉Peel is taken in a glass bowl

👉The peeling agent is then applied either with a brush or cotton-tipped applicator or gauze- moist
but not dripping

👉The chemical is applied quickly on cosmetic units on the entire face

👉Direction of strokes- OUTSIDE TO INSIDE - to prevent excess amount of peel getting near sensitive areas of face

👉Strokes- smooth & uniform
Feathering strokes are applied along the sides & jaw line to blend with surrounding skin and prevent demarcation lines

📍END POINT- Different for each peel

*GA peel- time factor
*TCA- Frosting – protein coagulation of keratin
*SA- Pseudo frost –immmediate whitening within 30seconds- crystallisation of SA on volatisation of vehicle on skin surface

*Time factor- most imp factor in GA peel
Time GA is kept in contact with skin
Start with ½ min→ ↑ by ½ min on every visit → max of 5 min.
Neutralisation of GA peel – 10-15% NaHCO3, followed by water
Pt discomfort – criteria for peel termination
Once erythema or epidermolysis occurs (grayish white appearance of the epidermis or small blisters), the peel must be neutralized immediately irrespective of the duration

*TCA & SA- once the end point is achieved, terminate the peel with cold water
Time lag between the application of TCA & appearance of frosting- 5-15 mins
The skin is gently dried with gauze and the patient is asked to wash with copious amounts of cold water till the burning subsides. The face is patted dry, and rubbing should be avoided. A sunscreen is applied before the patient leaves the clinic

📌Post peel care

👉Post peel period→ edema, erythema & desquamation occur.
superficial peels → lasts for 1-3 days
deeper peels→5-10 days.

👉Once skin starts peeling, sensation of tightening & cracking - apply emollients & keep the skin moist.Cold compresses or calamine lotion may be used to soothe the skin

👉Use only broad-spectrum sunscreens and bland moisturizers until peeling is complete.

👉Use retinoic acid or alpha-hydroxy acids at night, only after complete reepithelialisation-maintaining, enhancing/ as part of on - going treatment

👉NO rubbing/picking/scratching

👉NO facial procedures for 1 week

👉NO swimming pools/chlorinated water for 72 hrs

👉NO direct water spraying on face(showering)

📌Schedule:-

Superficial peels:

Superficial peels are repeated every 2-4 weeks, until the desired results are accomplished
Usually 4-8 sessions – acne
10-12 sessions- melasma, pigmentary d/o, photoaging
Thereafter, maintenance peels- as & when required

Medium and deep peels:

Usually performed as single procedure
Should not be repeated < 6 months in medium depth & < 1 year in deep peels.
Medium- upto upper reticular dermis
Deep- mid reticular dermis
Suitable for Fitzpatrick skin types I–III

Agents for medium depth peels

*35- 50% TCA
*Combination peels – to reduce sideeffects of individual agents, 2 or more agents of lower concentration are combined- work synergistically & ↑ depth & safety of peel

📌Combination peels

📍BRODY PEEL –Solid CO2 + 35% TCA

📍COLEMAN / COLEMAN FRUTELL PEEL – 70% GA + 35% TCA

📍MONHEIT PEEL -Jessner’s solution + 35% TCA

📌Agents for deep peels

📍> 50% TCA

📍Phenol containing preparations: Protoplasmic poison, 88%, 45-55%,photoaging

📍BAKER- GORDON PEEL - Phenol (88%)3ml, Tap water 2ml, Septisol(liquid soap) 8drops, Croton oil 3 drops.

Indications of deep peels:-

*Superficial /Deep rhytids secondary to photoaging
(Glogau type II,III- medium, type IV- deep)
*Severe or extensive Actinic keratosis & solar lentigines
*Acne scarring
*Melasma -dermal
*Facial skin rejuvenation

Contraindications of deep peel:-

*Dark skinned patients- (Fitzpatrick skin types IV–VI)-risk of prolonged hyperpigmentation
*Phenol peels- C/I in patients with a history of cardiac, renal or hepatic disease

👉PROCEDURE FOR DEEP PEELS
Sedation & analgesia are given, as the peels are painful.
Cardiac monitoring to detect cardiotoxicity and intravenous access to maintain hydration are essential for full-face phenol peel
Skin is degreased with acetone and the peeling agent is applied sequentially in the cosmetic units with a cotton tip applicator.
For phenol peels, the procedure is spread over 90 minutes with 15-minute intervals between applications in different cosmetic units →↓risk of absorption and side effects
A deep frost is seen on application →fades to erythema within 30 minutes→Edema and crusting in 2 to 3 day →slowly resolve over 7 to 10 days.
Post operative care- soak face with plain water ,bland emollient or antibacterial ointment→ ↓ heavy crusting

📌NON FACIAL PEELS

📍Chemical peeling on non-facial areas such as the neck, back,chest, shoulders and forearms ; axilla for hyperpigmentation

📍Agents used : TCA(20-35%), GA(50-70%), SA(20-30%)

📍DIFFERENCES:-
*Non-facial skin has fewer pilosebaceous units than facial skin →re-epithelization of the skin is delayed
*↑ risk of systemic toxicity since the chemical agent is applied on a larger surface
*Chest, back- More prone to develop scarring, keloid formation and abnormal texture

📍IMMEDIATE COMPLICATIONS
Pain, burning sensation
Pruritis
Erythema
Epidermal / dermal burns
Edema
Ocular injuries

📍DELAYED COMPLICATIONS
1. Pigmentation: Postinflammatory hyperpigmentation & hypopigmentation
2. Infection: Bacterial (Staphylococcus, Streptococcus,Pseudomonas), viral (Herpes simplex) and
fungal(Candida)
3.Allergic reactions
4. Milia
5. Acneiform eruptions
6. Lines of demarcation
7.Persistent erythema
8. Scarring - rare in superficial peels.
9. Toxicity-Rare, it may occur with salicylic acid , phenol and resorcinol- when applied to large areas→ gets absorbed → systemic toxicity

*Salicylism- Nausea and vomiting, tinnitus, deep & rapid breathing
*Phenol toxicity- cardiac arrhythmias, nephrotoxicity andhepatotoxicity
*Resorcinism- Nausea and vomiting,diarrhoea, syncope, bradycardia

📍Peels in pregnancy:-

 – AHA:Category B

- Salicylic acid-contraindicated

📌Conclusion

Chemical peeling is a simple office procedure for the treatment of dyschromias, photo aging and superficial scarring that can lead to excellent cosmetic improvement.
Careful patient selection, priming of the skin, standardization of peels, post-peels care and
maintenance are essential to achieve excellent results