Download Chemical peels

Lip Teh
March 2006
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SKIN TREATMENTS
SUNSCREENS
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Dependant on application thickness
Application 1hr before helps bind sunblock to skin
Reapplication is required
SPF = compares minimal time required to produce erythema compared with no
agent – agents only work to lengthen time taken to absorb UVR
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March 2006
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RETINOIDS
 repairs photodamage – sustained improvement in skin wrinkling and texture
 acts as a hormone – binds to DNA to regulate gene transcription
 inhibits induction of c-Jun protein by UV irradiation and prevents induction of
matrix metalloproteinases
 side effects (retinoid dermatitis)
1) erythema
2) peeling (receptor mediated – dose dependant)
3) xerosis
4) pruritus
 no increased incidence of cutaneous neoplasms with topical use
BLEACHING AGENTS
Pigmentation
 type and amount of melanin synthesized by the melanocyte and its distribution
pattern in the surrounding keratinocytes determines the actual color of the skin.
 Melanin forms through a series of oxidative reactions involving the amino acid
tyrosine in the presence of the enzyme tyrosinase
 first step involving tyrosinase is the most critical because the remainder of the
reaction sequence can proceed spontaneously at physiological pH.
 in the presence of dopachrome tautomerase and DHICA oxidase, eumelanin
(brown-black pigment) is formed
 In the presence of cysteine or glutathione, pheomelanin, a yellow-red pigment, is
formed.
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March 2006
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Hydroquinone (2% or 4)
 Inhibits tyrosinase (converts tyrosine to melanin)
 considered one of the most effective inhibitors of melanogenesis in vitro and
in vivo.
 Mechanism of action:
a. reversible inhibition of cellular metabolism by affecting both DNA and
RNA synthesis. Can be considered a potent melanocyte cytotoxic
agent with relatively high melanocyte-specific cytotoxicity.
b. a poor substrate of tyrosinase, thereby competing for tyrosine oxidation
in active melanocytes.
 Topical application for weeks to months
 Side effects
a. ochronosis
i. characterized by progressive darkening of the area to which the
cream is applied
ii. generally has been observed in black patients and after use of
high concentrations of HQ for many years
iii. mutagenic properties in hamsters, HQ is banned in Europe for
use as a depigmenting agent.
b. contact dermatitis
 tretinoin has been used to enhance the efficacy of HQ
 Unstable to store
Kojic acid
 Tyrosinase inhibitor
 used in concentrations ranging from 1-4%.
 reported to have high-sensitizing potential and cause irritant contact
dermatitis
Azelaic acid (20%)
 weak competitive inhibitor of tyrosinase in vitro
 also has an antiproliferative and cytotoxic effect on melanocytes.
 has been combined with glycolic acid (15% and 20%), and this has an
efficacy has been compared with HQ 4% in the treatment of facial
hyperpigmentation in dark-skinned patients.
 Transient pruritus and erythema (5-10%)
CHEMICAL PEELS
 Affects epidermis and superficial dermis
 Smooths surface irregularities
 Alters skin pigmentation
Mechanism of action
 Sensitivity to peels correlates with absence of tanning ability
 Pigmentary problems is more common in darker skinned patients
 effect of the peel (and complications) is due to the depth of injury
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March 2006
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epidermis regenerates from the epidermal appendages located in the remaining
dermis. This process begins within 24 hours of wounding and is usually complete
in 7-10 days.
new epidermis shows greater organization and vertical polarity, with the
disappearance of actinic keratoses and lentigines.
Dermal regeneration is a slower process but is usually complete within several
months. The regenerated dermis demonstrates less elastosis and improved
organization, with compact horizontally arranged bundles of collagen interspersed
with elastic fibers.
overall result is soft supple skin that appears more youthful with fewer rhytids and
dyschromias.
Considerations
1) ↑ actinic damage = ↑ keratin thickness = ↑ need for aggressive peel
2) epidermis can be removed without risk of scarring
3) destruction of epidermal basal layer will cause hypopigmentation
4) dermal injury will cause some scarring (fibroplasias)
5) depth of wound that determines final result
Indications
 superficial
o dyschromias, melasma
o comedonal acne
o skin refreshing.
 Deep medium peel
o actinic changes and preneoplasia,
o fine rhytides
o pigmentary dyschromias
o selected superficial scars
o rosacea.
Contraindications
 For deep rhytids and overall skin laxity the patient may be better served with a
rhytidectomy.
 Dynamic wrinkles may be better treated with Botox.
 Poor candidates:
o collagen vascular disease (bad scars)
o history of previous radiotherapy to head/neck
 consider a punch biopsy first to assess the presence of enough skin
appendages
o history of hypertrophic/keloid scarring
o Patients with a decreased number of epithelial appendages from prior
radiation treatment or isotretinoin (Accutane) use within 1-2 years because
healing will proceed more slowly and scarring is more likely.
o advanced HIV disease
o Fitzpatrick type 5/6 (unless using superficial peel)
o general poor mental and physical well-being
o patients with cardiac disease must be evaluated by a cardiologist before
consideration of phenol peeling.
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March 2006
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o History of melasma, recent pregnancy, estrogen use (or other
photosensitizers), and unwillingness to avoid the sun may portend postpeel hyperpigmentation problems.
Classification
 Very superficial peeling agents
o 10-20% trichloroacetic acid, Jessner's solution applied in one to three
layers, and glycolic acid 20-30%.
 Superficial peeling agents
o trichloroacetic acid 20-30%, Jessner's solution applied in four or more
layers, and glycolic acid 40-50%
 Medium
o trichloroacetic acid in concentrations of 30-50% and trichloroacetic acid
plus various other adjunctive solutions such as Jessner's, solid carbon
dioxide, and glycolic acid.
 Deep
o 88% Phenol
o Baker-Gordon peel - produces the most dramatic results and is the most
effective peeling agent currently used.
 Deepest
o Baker-Gordon peel with tape occlusion
AGENTS
Preconditioning
 Bleaching agents
o Consider for deep peels to prevent hyperpigmentation in dark patients
 Transretinoic acid (Retin-A, Renova),
o exfoliative agent, facilitates uniform penetration of the peeling agent and
promote more rapid re-epithelialization.
o applied nightly or every other night for several weeks prior to peeling,
depending on the degree of skin irritation caused and patient tolerance.
o promotes a thinning of the stratum corneum with shedding of
keratinocytes, and activation of fibroblasts
Alpha Hydroxy Acids
Glycolic or lactic acid
 Low concentrations (<30%, pH>3)
o ↓ keratinocyte cohesion at stratum granulosum = ↑desquamation
o Use as exfoliating agent
 High concentration (>50%, pH>2)
o Frank epidermolysis
o Use in chemical peeling – works in days
 pH determines depth of penetration
 lipid soluble; therefore, it is a good peeling agent for comedonal acne.
 Its anti-inflammatory and anesthetic effects result in a decrease in the amount of
erythema and discomfort that generally is associated with chemical peels.
 ? works better for keratosis and lentigines than wrinkles
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March 2006
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Jessner’s Solution
 Contains
1) Resorcinol 14%
2) salicylic acid 14%
3) lactic acid 14%
4) ethanol
 Superficial keratolytic agent – stronger than 70% glycolic peel
 Can be used to prepare skin for TCA
 Use only for face
Salicylic Acid (Beta hydroxyl acid) 30% in ethanol
 Similar strength to Jessner’s
 Works in 2-7 days
 4 weeks between treatments
 Advantages
1) uniform application – naked eye, Wood’s lamp
2) little risk of overpeeling – volatizes in 3.5mins
Dry Ice (carbon dioxide)
 Used in preparation for TCA peel
 uses a solid block of carbon dioxide ice dipped in an acetone-alcohol mixture and
then applied to the skin for 5-15 seconds, depending upon the desired depth.
 Carbon dioxide is easier to use, and the depth of the peel can be controlled more
easily than with liquid nitrogen
 Not as convenient as Jessner’s solution
Phenol
 George MacKee 1903 (dermatologist)
 Long lived clinical and histological effects
 causes keratolysis and keratocoagulation.
 Predictable deep partial chemical burn – all or nothing effect
 In contrast to other agents, increasing the concentration of phenol actually
decreases the penetration up to a point, because the ensuing destruction forms a
barrier to further penetration
 Most effective for
1) fine/coarse wrinkles
2) irregular pigmentation
3) actinic keratosis
 Not effective for
1) telangiectasias (deep dermis)
2) acne scarring
3) capillary hemangiomas
4) hyperpigmentation from SSG
 Poor candidates
1) dark skin
2) red hair with freckles
3) male
 thicker, oilier skin that risks uneven penetration of the peeling agent.
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March 2006
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less likely to be willing to use camouflage makeup in the event of
pigmentary disturbances.
4) wrinkles in neck, thorax and extremities (↓ skin appendages)
Baker-Gordon formula (1961) - phenol 88%, 2 mL distilled water, 8 drops
Septisol, and 3 drops croton oil.
Hetter developed Heresy phenol formula (1996)
 phenol-croton in varying combinations
 believed that croton oil(skin irritant) was the active ingredient in the peel
solution
 minute variations in its concentration critical to the outcome of the peel.
Depth increased with occlusive dressing
Does not affect hair growth, avoid contact with eyes
Histology
 Penetration into upper reticular dermis
 Removal of damaged elastotic skin and replacement with new stratified collagen
layer – deep dermal homogenization of collagen
 Healing begins from epithelial appendages
Immediate-Early
 Keratocoagulation
 Marked inflammatory response
Intermediate
 Epidermal regeneration (48 hours to 7 days) - Epidermal uniformity
 Dermal regeneration (48 hours to 3 months) - Rigid, organized, compact collagen
bundles
Long term
 Differences detected up to 20 years post treatment
 No difference in melanocyte population but ↓ synthesis
Toxicity
 Absorbed thru skin, Detoxified in liver, Excreted in kidneys
 Depress cardio-resp centers
o high incidence of significant cardiac arrhythmia when 50% of the total
face was treated in less than 30 min
o cardiac monitoring of patients and easily accessible resuscitation
equipment is required when performing a fullface phenol peel.
 Fatal dose= 8-15gm
Comparison with other deep methods
1) Dermabrasion
 Good for perioral region
 Better for acne scarring
 Less bleaching
 Less useful for facial wrinkles
 Cannot be used for periorbital wrinkles
2) Laser resurfacing
 Good for perioral and periorbital wrinkling
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March 2006
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Less effect on facial pigmentation
Less effective for coarse wrinkles – phenol produces a new zone of collagen
that is thicker than that produced by laser
Similar recovery period
3) TCA peel
 Compared with TCA, a phenol-croton oil peel produces less hypertrophic
scarring for any given level of wrinkle abrasion.
Technique (phenol)
 Performed in surgical facility
 Sedation unless regional or spot peeling
 IV, cardiac monitoring and oximetry
 Prior to the peel, the patient thoroughly cleanses the face with nonresidue soap on
the evening before and morning of the procedure.
 Instructed not to apply makeup or moisturizers.
 Skin is cleansed immediately prior to the procedure to remove any remaining
traces of makeup or oils. This step is absolutely essential to prevent uneven
penetration of the peeling agent.
 Cotton tip applicator
 Apply regionally
 No more than 25% of the face should be peeled before a 10-20 minute break is
taken. Entire peel should thus take an hour or more.
 Like TCA, the time spent applying the agent and the amount of sponge strokes
used will be proportional to the depth of penetration.
 Does not cause alopecia
 Occlusive dressings
- increases depth but more painful and can’t monitor wound
 Watch for lid oedema (first 6-12hrs)
 causes an intense burning upon application that may last 4-6 hours, which is much
longer than the discomfort associated with other peeling agents.
Trichloroacetic acid (15-60%)
 Used for aging skin since 1962
 a keratocoagulant that produces a frost or whitening of the skin, which is
dependent on the concentration used.
 associated with an intense burning that usually resolves within 30 minutes.
 Administer appropriate analgesia prior to the procedure and consider regional
nerve blockade.
 Penetration depth dependant on
1) concentration of preparation
2) preparation of skin
a. washing and degreasing to remove surface oils
b. mechanical removal of surface debris
c. chemical disruption with keratolytics
- mild acids or tretinoin
- may accelerate healing
 Depth judged by
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March 2006
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1) appearance of skin after application
2) turgor of skin on light palpation
3) time taken to return to normal color
10-30% = light, 35% = intermediate, 50-60% deep
Concentrations higher than 35% carry a high risk of scarring.
not recommend over recent facelift (skin slough)
Advantages over phenol
1) Safer side effect profile – low systemic absorption
2) Tailor the dose thus the degree of peeling - less risk of hypertrophic scarring
3) Lesser effect on melanocyte metabolism – less bleaching
Limitations compared to phenol
1) less penetration
2) less neocollagen formation
3) less effective for coarse wrinkles
4) less effective for perioral region
5) less effective to treat blotchy pigmentation
General Complications of Chemical Peeling
Early
1) Pain
2) Photosensitivity
a. Need to wear sunscreen for 4-6 months
b. Higher risk in those taking oral contraceptive pills, exogenous
estrogens, or other photosensitizing medication
3) Erythema
a. May persist for 10-12 weeks
b. Treated with topical steroids
4) Pruritus
a. Oral antihistamines
5) Infection
a. Herpes - 50% risk of perioral herpes if patient has a past history. Some
advocate prophylaxis in all patients
b. Pseudomonas - local soaks with an agent such as 0.25% acetic acid and
appropriate antibiotics
6) Cardiac arrthymia - phenol
Late
1) Hypopigmentation
a. More common with phenol, type III/IV skin
2) Hyperpigmentation
a. use sunscreen daily for 6-12 months
3) Milia
a. appear about 2-3 weeks after reepithelialization
b. aggravated by ointments due to occlusion of the sebaceous glands.
c. Usually resolves spontaneously
4) Hypertrophic scarring
a. Worst around anterior neck
5) Ectropion