Keywords
chemical peel - chemoexfoliation - phenol–croton oil peel - skin resurfacing
There has been a boom in skin care products, medical devices, and skin rejuvenation
therapies over the past few decades. This is likely because of modern medicine increasing
both the average lifespan and quality of life in the general population. Due to this
development, there has been a greater demand for treatment of age-related skin changes.
As many new over-the-counter options in skin rejuvenation are increasingly being used
by patients, they are now more prepared for medical grade chemical peels for more
potent and lasting results. The different variations of chemoexfoliation have been
used for rhytids, actinic damage, lentigines, and dyschromias.
The goal of the following section is to describe the most recent knowledge about chemical
peeling and to expose the previously accepted yet incorrect dogmas. Chemical peeling,
when practiced with knowledge and good technique, can yield excellent results in skin
rejuvenation.
Patient Selection
As with any patient encounter, the initial consultation provides an opportunity to
thoroughly assess the patient's history and physical examination. The patient must
both be a physical candidate for a chemical peel and have appropriate expectations
for their postpeel results. For non-Caucasian patients, in particular African-American
patients, a personal and family history of keloid and hypertrophic scar formation
should caution the practitioner from aggressive resurfacing. Skin-related changes
such as rhytids and photodamage must be distinguished from other changes such as volume
loss or jowling. Ideally, a chemical peel patient will have blue eyes, fair skin,
and shallow rhytids. However, the majority of chemical peel patients will not fit
this exact description. Most commonly, the Fitzpatrick scale is used to help define
a patient's skin type ([Table 1]).
Table 1
Fitzpatrick skin type scale
Skin type
|
Skin color
|
Characteristics
|
I
|
White; very fair; red or blond hair; blue eyes; freckles
|
Always burns; never tans
|
II
|
White; fair; red or blond hair; blue, hazel or green eyes
|
Usually burns, tans with difficulty
|
III
|
Cream white; fair with any eye or hair color; very common
|
Sometimes mild burn, gradually tans
|
IV
|
Brown; typical Mediterranean Caucasian skin
|
Rarely burns, tans with ease
|
V
|
Dark brown; mid-eastern skin types
|
Very rarely burns, tans very easily
|
VI
|
Black
|
Never burns, tans very easily
|
Patients can also be rated by their skin type, texture, complexion, photoaging, and
so on using categorizing schemes such as the one by Glogau ([Table 2]).
Table 2
Glogau skin classification scale
Group I (mild)
|
Group II (moderate)
|
Group III (advanced)
|
Group IV (severe)
|
No keratoses
|
Early actinic keratoses: slight yellow skin discoloration
|
Actinic keratoses: obvious yellow skin discoloration with telangiectasias
|
Actinic keratoses and skin cancers
|
Little wrinkling
|
Early wrinkling: parallel skin lines
|
Wrinkling present at rest
|
Wrinkling: much cutis laxa of actinic, gravitational, and dynamic origin
|
No scarring
|
Mild scarring
|
Moderate acne scarring
|
Severe acne scarring
|
Little or no makeup
|
Little makeup
|
Wears makeup always
|
Wears heavy layers of makeup
|
The medical history of the patient must be reviewed before any chemical peeling occurs.
Relative contraindications for any resurfacing procedure include smoking, diabetes,
active or frequent herpes simplex virus infections, cutaneous radiation history, hypertrophic
scarring, or keloid history. Photosensitizing drugs, exogenous estrogen, and birth
control pills should be avoided because of the increased risk of hyperpigmentation.
Patients should also be warned not to have plans to become pregnant within 6 months
after chemical peeling due to elevated estrogen levels of pregnancy.[1]
[2]
Smoking and sun exposure should always be addressed in the planning stages. Chemical
peels on the faces of chronic smokers can lead to poor tissue healing due to the microvascular
damage from smoking. It is recommended that smokers stop 1 month before the peel and
continue abstinence for at least 6 months afterward. Likewise, it should be recommended
to patients that for 3 months, prolonged sun exposure should be avoided after the
peel. If this is unacceptable to the patient, other options besides chemical peeling
should be explored.
An absolute contraindication to chemical peeling, or any facial resurfacing, is recent
use of isotretinoin (Accutane). Isotretinoin prevents reepithelialization from hair
follicles and sebaceous glands, and chemical peeling relies primarily upon this reepithelialization
for healing. The most current recommendations are to stop isotretinoin for 12 to 24
months before the peel.
Finally, the patient and the practitioner must have agreed upon the reasonable expectations
of the peel. The patient's axillary skin can represent the final result of the chemical
peel as long as this region has not previously received excessive sun damage.[3]
Preparation
After the patient selection and planning is completed, one must address patient concerns,
establish realistic expectations, and, ultimately, decide on the appropriateness to
pursue the resurfacing procedure. Sunscreens should be started 3 months beforehand
to prevent prepeel tanning or sunburns. Part of the purpose of this is to decrease
the melanocyte activity before the peel. Topical tretinoin (Retin-A; Bausch Health
Companies Inc.) is recommended for 6 to 12 weeks before the peel. The topical tretinoin
has been shown to have a synergistic effect with trichloroacetic acid (TCA) peels
and can sustain the effects of these peels.[4]
[5]
[6] Tretinoin leads to exfoliation of stratum corneum and increased melanin distribution
and aids in proper penetration of the peel solution. It contributes to a thickened
and uniform epidermis, which aids in uniform application of the peeling agent.
Up to 6 weeks before resurfacing, patients can be started on topical therapies to
increase the rate of epithelialization, stabilize melanocyte activity, and reduce
local inflammation. The dosing ranges from 0.025 to 0.1%; however, no literature has
shown improved results with the higher dosing. Patients should be counseled of the
possible side effects of tretinoin, such as erythema, flakiness, or skin irritation.
If this was to occur, the dose can be reduced or the medication can be discontinued
entirely.
Another beneficial drug in the preparation of chemical peel patients is hydroquinone.
Hydroquinone is mostly used in patients with dyschromias and lentigines or patients
with Fitzpatrick skin types III, IV, V, and VI due to the elevated risks of postpeel
postinflammatory hyperpigmentation (PIH). The mechanism of hydroquinone is to block
the conversion of tyrosine to L-Dopa by tyrosinase, thereby decreasing melanin production.
In applicable patients, hydroquinone in a concentration of 4 to 8% should be started
4 to 6 weeks before chemical peeling. The authors use a topical preparation of 0.025%
tretinoin, 8% hydroquinone, and 1% hydrocortisone in a moisturizing cream base. Similar
to tretinoin, hydroquinone should be restarted after the peel once the patient's skin
is ready to tolerate it. Topical therapy is stopped 3 to 4 days before the procedure
but may be restarted 1 week after the procedure. Oral antiherpetic prophylaxis is
initiated 3 days before resurfacing and continued 5 to 7 days until reepithelialization
is complete.
The first line of resistance to bacterial infection is the skin, and resurfacing procedures
can reduce this barrier. This can lead to infections by cutaneous bacterial flora
such as staphylococcal or streptococcal species. Appropriate antibacterial coverage
should begin before the peel as prophylaxis. The senior author (D.S.M.) uses cephalexin,
250 mg four times a day, 1 day before the peel and continues it for 7 days in the
postoperative period. In patients who are B-lactam sensitive, erythromycin, 250 mg
four times a day, can be used. To maintain a uniform depth of the peeling agent, it
is advisable to recommend avoiding microdermabrasion, waxing, or electrolysis for
3 to 4 weeks before peeling.
Superficial Peels
The workhorse peel for plastic surgeons, dermatologists, and aestheticians has been
the α-hydroxy acids (AHAs). AHAs are natural fruit, carboxylic acids, with the most
common AHA being glycolic acid or 2-hydroxyethanoic acid. Glycolic acid is derived
from sugarcane and is generally used in a concentration of 20 to 70%.[6]
[7] Salicylic acid, in concentrations of 20 to 30%, is also used in superficial chemical
peels.
α-hydroxy acids penetrate through the epidermis and into the most superficial layer
of the papillary dermis. They work by diminishing the cohesion between the keratinocytes
of the stratum granulosum. This leads to the sloughing of the abnormal cells and thins
the stratum corneum. These benefits generally last for 2 to 3 weeks.
A false sense of security should be avoided with AHAs. Glycolic acid can have a persistent
effect and penetrate deeply if not neutralized with water. If glycolic remains unneutralized,
the deeper penetration can lead to healing problems, crusting, and scarring. The anticipated
end of a glycolic acid peel procedure should be erythema and light peeling of the
epidermis.[8]
Jessner's solution (14 g of salicylic acid, 14 g of lactic acid, 14 g of resorcinol
in 100 mL of ethanol) is a superficial peeling agent with a high safety profile. The
number of coats applied determines the depth of penetration. If one to three coats
are applied, exfoliation of the stratum corneum occurs. If 5 to 10 coats are applied,
the depth of penetration continues down to the basal layer.
Deep Peels
The deep peel treats the deep rhytids of the lateral canthal and perioral regions
by penetrating down to the reticular dermis. While the papillary dermis is thought
to heal through reorganization, the reticular dermis is thought to heal through scarring.[9] With deep chemical peeling, the risk of scarring is higher and additional recovery
time is necessary.
The workhorse deep chemical peel agent was the Baker–Gordon formulation; however,
this lost some popularity as TCA peels and CO2 laser surfacing rose into the field. The Baker–Gordon peel did offer arguably unparalleled
treatment for deep facial rhytids, but the irreversible hypopigmentation risk and
the cardiac/renal toxicity limited its applicability.
Another option for deep peels is the 50% TCA peel; however, a significant percentage
of patients develop scarring with this formulation. This catastrophic complication
halted the application of this strength of TCA solution.
Notwithstanding the risks of the Baker–Gordon peel, it does have a role in the correct
scenario. It is a very effective peeling option in patients with deepened rhytids
in distinct facial subunits with Fitzpatrick skin types I and II. Nonetheless, a high
level of technique and caution must be used to avoid overly deep peeling with this
solution. A uniform application of peeling solution with attention to the developing
frost will help prevent potential complications.
Medium-Depth Peels
The modern-day chemical peel discussions center around the medium-depth peeling agents.
Medium-depth peels penetrate through the epidermis and the papillary dermis and cause
some inflammation in the upper reticular dermis. Traditionally, the standard medium
peel has been the 35% TCA peel. It does not have systemic toxicities, and it is very
easy to store as it does not require refrigeration in its crystalline form. However,
the risk of scarring with TCA is much higher than with phenol-based peeling solutions.
TCA concentrations of 50% or greater greatly increase the possibility of scarring.[10] There have been no additional techniques that have proven beneficial in reducing
this risk of scarring.[11]
Providers have been combining 35% TCA solutions with other less potent agents to achieve
medium-depth peels without the risks of scarring. The depth of penetration of the
35% TCA peel solution is enhanced by an additional solution being first applied as
an epidermolytic. This technique was first described by Brody using CO2 ice and acetone to create an epidermal break for the TCA solution that follows.[12]
Monheit described another combination peel: Jessner's solution followed by 35% TCA.
Jessner's plays the role of penetrating the epidermis, and TCA is then applied once
the Jessner's solution has dried.[13] Frosting does not occur immediately, unlike with phenol peels, and 3 to 4 minutes
must be allowed for the full frost to form. Once the frost occurs, additional coats
can be applied to reach the desired depth of peel. Care is taken with additional applications
of TCA, as this has a cumulative effect and leads to a deeper peel.[14] This can increase the chances of hypopigmentation and scarring.
There are also combination peels made out of glycolic acid and 35% TCA, as described
by Coleman and Futrell. His histological examinations demonstrated that it penetrated
slightly deeper than Jessner–TCA combination peels.[15]
Brody researched the complications of these three combination peels and found that
their risks of scarring were less than 1%. This scarring risk placed them on par with
other skin resurfacing modalities such as phenol–croton oil peels or CO2 laser resurfacing.
Modified Phenol–Croton Oil Peels
Modified Phenol–Croton Oil Peels
The all-or-none qualities of the Baker-Gordon phenol–croton oil peel has led to TCA
peel solutions taking a prominent role in modern-day chemical peel practices. The
literature on deep chemical peels began in the 1950s and 1960s when plastic surgeons
first adopted the phenol–croton oil solutions. Litton was the first to present these
formulas to the American Society of Plastic and Reconstructive Surgery in the late
1950s. Soon afterward, the classic formula was credited to Baker in the early 1960s.[16]
Around this time in the 1960s, Adolph Brown wrote extensively about phenol–croton
oil peels. He presented three doctrines of phenol peeling. First, increasing the concentration
of phenol (80–90%) would work to prevent further penetration by creating an immediate
keratocoagulation. Second, adding a saponin to the solution would increase the depth
of penetration. Third, the role of croton oil was merely to buffer the solution. This
led to many believing that phenol was the sole active ingredient within the Baker
formula. This resulted in the belief that phenol in lower concentrations was more
dangerous because of deeper penetration and that croton oil had no role in the depth
of peel. These beliefs lasted until they were questioned by Gregory Hetter in the
1990s.
Hetter's experiments refuted the previously described dogmas of the mid-20th century.
A solution of 18% phenol without croton oil demonstrated minimal postpeel effect.
With a 35% phenol solution, mild keratolysis occurred with no dermal effect. It was
only with an 88% phenol solution that a papillary dermal effect took place. More substantial
postpeel effects were noticed once croton oil was added to the phenol solution. Additionally,
varying croton oil concentrations had different results. A 0.7% croton oil concentration
solution required a 7-day recovery period, whereas a 2.1% croton oil concentration
required an 11-day recovery period. Hetter thus postulated that higher concentrations
of phenol (88%) without septisol peel more deeply than lower concentrations (50 and
35%). He concluded that increasing the concentrations of croton oil in phenol formulations
results in deeper peels.
Hetter also realized that the healing times would be shortened by diluting the concentration
of croton oil in these formulas, signifying a shallower depth of penetration. He expanded
on this by claiming that the concentration of phenol, in fact, had little to do with
the depth of penetration. Obagi was the first to suggest that different concentrations
of these formulas should be applied to the discrete subunits of the face. Hetter used
this postulation to apply varying concentrations of croton oil to the facial subunits
([Fig. 1]). He found that the temple and lateral brow could only withstand concentrations
up to 0.6%, the cheeks and forehead could only tolerate concentrations up to 0.8%,
and the perioral region could tolerate croton oil concentrations up to 1.6% before
the risk of complications rose. Lastly, Hetter felt that 1% croton oil solutions were
the upper threshold for safe use to avoid serious risk of hypopigmentation.
Fig. 1 Facial subunit markings demonstrating various concentrations of peel solution, as
described by Hetter.
Hetter first created his formulations using phenol at 33% to carry croton oil at one
drop (0.35%), two drops (0.7%), and three drops (1.1%) of concentrations. However,
he soon switched to a more standardized system of measurement rather than relying
on a dropper, which is naturally unreliable. He converted one drop into 1 cm3 and used this conversion to make a stock solution of 0.04 mL of croton oil per 1
mL of phenol. From this, he could make different croton oil formulations of 0.4, 0.8,
1.2, and 1.6% in a constant phenol concentration ([Table 3]).
Table 3
Hetter peel formulations (stock solution = 24 mL + 1 mL croton oil [4% croton oil])
Croton oil %
|
0.2%
|
0.4%
|
0.8%
|
1.2%
|
1.6%
|
Distilled water
|
5.5 mL
|
5.5 mL
|
5.5 mL
|
5.5 mL
|
5.5 mL
|
Septisol
|
0.5 mL
|
0.5 mL
|
0.5 mL
|
0.5 mL
|
0.5 mL
|
USP phenol 88%
|
3.5 mL
|
3.0 mL
|
2.0 mL
|
1.0 mL
|
0 mL
|
Stock solution containing phenol and croton oil
|
0.5 mL
|
1.0 mL
|
2.0 mL
|
3.0 mL
|
4.0 mL
|
Total
|
10 mL
|
10 mL
|
10 mL
|
10 mL
|
10 mL
|
Technique
The skin must be sufficiently prepared before applying the peeling solution. This
starts with a vigorous cleaning with acne wash or septisol the evening before and
the morning of the chemical peel. Preoperative oral sedation, 10 mg of diazepam and
100 mg of Dramamine, helps to relieve patient anxiety. The antihistamine serves to
reduce oral secretions and protect the patient's airway during the sedation. As the
patient will have had nothing to drink since the previous night, intravenous fluids
should be started prior to bringing the patient to the procedure room.
Preoperative marking consists of marking the patient's submandibular shadow while
in the upright position. This helps to prevent noticeable delineation between the
peeled and unpeeled area of the neck. The patient is then placed in the supine position.
Supraorbital, infraorbital, and mental nerve blocks are performed with 50:50 mixture
of 2% lidocaine and 0.5% bupivacaine. Local anesthetic is also applied through a field
block over the areas to be peeled. Epinephrine will slow the clearance of the phenol
and is thus avoided. The face is meticulously degreased with an acetone-soaked gauze.
Any remaining skin oil on the patient's face will impair the uniform application of
the peeling agent. Some authors like Obagi and Hetter suggest using a wrung-out 2-inch
by 2-inch gauze for the application of the peeling agent. However, the senior author
(D.S.M.) feels that using a wide cotton-tipped applicator allows for superior control
of application.
As opposed to TCA where the frost can take 3 to 4 minutes to occur, with phenol-based
chemical peels, the frosting occurs almost immediately. This means that the uniformity
of depth, and need for reapplication, is almost immediately obvious to the provider
in a phenol-based peel. Medium-depth peels should result in a level II to III frost
([Fig. 2]).[17]
-
Level I: erythema with stringy or blotchy frosting.
-
Level II: white coat with erythema showing through (it should be used for eyelids
and areas of bony prominences, such as zygomatic arch, malar region, and chin, which
all have a higher rate of scarring).
-
Level III: solid white frost with little or no background erythema.
Fig. 2 A level III frost after application of phenol–croton oil solution, with a white frost
over the treated skin.
The facial subunits are divided by the severity of lentigines, rhytids, and photodamage,
as well as skin thickness. The senior author (D.S.M.) uses 0.8% croton oil Hetter
solution in areas of thicker skin and deeper rhytids (Glogau III and IV), such as
the glabella and perioral regions. Intermediate areas (Glogau II and III) are treated
with 0.4% croton oil Hetter solution. An 89% phenol solution is used for feathering
along the borders of the peeled areas to achieve an even postpeel result. A classic
Baker formula can be used in patients who are Fitzpatrick types I or II and have severe
Glogau IV rhytids in the upper lip.
Between each facial subunit, 10 to 15 minutes are allowed for adequate clearance of
the phenol. The Hetter solution requires less clearance time due to lower phenol compared
with the Baker–Gordon peel. The entire face can be peeled over 30 to 60 minutes. In
case a minor supraventricular arrhythmia occurs, the peel should be paused until the
patient returns to normal sinus rhythm.
The peel should continue up to and even into the hairline when applying the peeling
solution to the forehead and temporal regions. Phenol and croton oil will not affect
the pigment of the hair follicles. Additionally, the peel should continue just over
the vermilion border in the perioral area. This is because the margin of each peeled
region will have a distinct line of reactive hyperemia. These lines of hyperemia should
be included and peeled when peeling adjacent facial subunits to prevent any resultant
lines of demarcation. The skin can be stretched taut for deep wrinkles of the perioral
region to evenly apply the peel to these rhytids. Unlike with glycolic acid peels,
phenol–croton oil peels do not need to be neutralized because of the completed reaction
as demonstrated by the frost.
An area to exercise caution is in the lower eyelid region. The phenol–croton oil peel
should be applied to within 3 mm of the lower eyelid margin and then stopped. The
sedated patient can develop tearing during the peeling procedure, and these tears
should be wiped away to prevent the peeling solution from tracking up along the tear
into the eye. The upper eyelid lacks the sebaceous glands that are necessary for reepithelialization
following a peel, and therefore the peel solution is not applied to this area.
The patient can experience an immediate burning sensation if there were any areas
of inadequate local anesthesia. In this case, the sensation will last for approximately
15 to 30 seconds. The burning sensation can then return approximately 30 minutes later
and can last for the remainder of the procedure day. The bupivacaine in the local
anesthetic blocks should provide anesthesia for hours following the peel. This is
a part of the reason why it is critical to apply comprehensive local anesthetic blocks
to the peeled areas.
Postoperative Period
A thick coat of emollient is applied to all of the peeled skin areas once the last
area of frosting dissipates and only erythema remains. These emollients are not occlusive
and therefore do not affect the depth of the peel. The patient is instructed to maintain
a steady coat of this emollient over their entire peeled region by reapplying four
to five times per day or as often as needed. This is continued for the duration of
the postpeel period until fresh skin is visible and the area has fully peeled.
The healing process consists of four stages. The first stage occurs over the first
12 hours and consists of facial inflammation. The epidermis becomes leathery and begins
to separate from the dermis. The underlying treated dermal layer will become necrotic
and being to slough. The applied emollient helps in removing this necrotic skin from
the underlying tissues. The second stage is desquamation, which occurs over the next
3 to 7 days ([Fig. 3]). This exposed the underlying erythematous dermis. The third stage is reepithelialization,
which partially coincides with desquamation and occurs between days 2 and 10 following
the peel. Reepithelialization will be demonstrated by the changes in dermal color
from bright red to a lighter shade of pink. The final stage is fibroplasia and occurs
toward the end of the first week and continues for 12 to 16 weeks following the peel.
This final period is when the full benefits of the chemical peel become apparent ([Figs. 4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]). During this time, the skin will undergo new collagen formation, reorganization
of the collagen, and neoangiogenesis.
Fig. 3 Desquamation of the skin that takes place in the first 7 days following a phenol–croton
oil peel.
Fig. 4 Preoperative photograph of a patient with diffuse fine rhytids and photoaged skin.
Fig. 5 Post phenol–croton oil peel photograph with reduction of the fine rhytids and treatment
of the photoaged skin.
Fig. 6 Preoperative photograph of a patient with severe photodamage and moderate dyschromias
and fine rhytids.
Fig. 7 Post phenol–croton oil photograph with treatment of the photodamage, dyschromias,
and rhytids.
Fig. 8 Preoperative photograph of the perioral region with severe rhytids.
Fig. 9 Post phenol–croton oil peel photograph with treatment of perioral rhytids.
Fig. 10 Preoperative photograph of a patient with diffuse fine rhytids in the perioral, malar,
and periorbital regions.
Fig. 11 Post phenol–croton oil photograph with treatment of diffuse fine rhytids.
The patient is instructed to avoid any direct, prolonged sun exposure for 12 weeks
following the peel. During this period, the skin is vulnerable to ultraviolet light
exposure and is at a risk of resultant hyperpigmentation. The senior author (D.S.M.)
also recommends avoidance of sunscreens for the first 6 weeks. Many chemical sunscreens
include the ingredient para-aminobenzoic acid, which can cause erythema, irritation,
and induration of the healing skin. It is also recommended that women avoid birth
control pills during this same time period, as the increased estrogens can lead to
hyperpigmentation.
Complications
Cardiac Arrhythmias
Even in patients who have been properly selected and adequately hydrated before their
chemical peel, a reversible cardiac arrhythmia can possibly occur. The common presentation
is a supraventricular tachycardia that occurs within 30 minutes of starting the peel
and can evolve into paroxysmal atrial tachycardia, ventricular tachycardia, paroxysmal
ventricular contractions, and, possibly, atrial fibrillations. The best way to manage
any of these aforementioned progressive arrhythmias is to prevent them from occurring
in the first place. As soon as a supraventricular tachycardia, or other irregular
rhythm, is noted, the peel should be immediately paused and adequate hydration should
continue. At this point, the rhythm should eventually return to normal sinus rhythm
as the phenol is cleared. The phenol peel may proceed carefully with attention to
the rhythm monitor once the rhythm has returned to normal. In the rare instance that
the rhythm does not naturally return to a normal rhythm, proper medical procedures
should be undertaken for that aberrant rhythm.
Delayed Reepithelialization
Any area of the face that does not fully reepithelialize within 10 days should be
considered prolonged.[18] This phenomenon is more common with deeper phenol peels (Baker formula) and TCA
peels. It is important to rule out the presence of underlying infections or contact
irritants and not merely dismiss prolonged healing times as coincidentally. The risk
of scarring can rise precipitously if these areas are not checked daily and treated
accordingly.
Scarring
The most likely areas for scarring to occur are in the upper lip or over areas with
prominent underlying bone structure such as the mandible. Scarring most commonly is
because of an overly deep peel or from inattentive postoperative care. Again, the
risk of scarring is significantly elevated in isotretinoin users. The practitioner
should check to confirm that the patient is clearly producing skin oils after the
patient has stopped isotretinoin. Once developing, the scars can be treated with silicone
sheeting coverings and intralesional corticosteroids injections (Kenalog 20 mg/mL)
every 2 to 3 weeks. It is important to exercise caution in the injections of steroids,
as overinjection can lead to atrophy and skin depressions. As most scars will be erythematous,
a flash-lamp pulsed dye laser is helpful over multiple treatments.
Infections
In the case of a patient presenting with signs of cellulitis or infection, an appropriate
antibiotic regimen should be immediately started and continued for a 7- to 10-day
course. Similarly, herpetic viral infections can be problematic for a patient's natural
recovery. In the case of a herpetic outbreak despite appropriate prophylactic dosing
of antivirals, a course of valacyclovir, 1 g three times a day for 10 days, should
be used.
Postoperative Erythema
Postoperative erythema after a peel is common in all peel patients and is not unusual
for it to last longer than predicted. Hydrocortisone (2.5%) lotion is commonly prescribed
to aid in the resolution of this erythema. As this erythema is eventually subsiding
in the weeks following the peel, some patients will develop PIH. The typical scenario
for this is in a patient with excessive sun exposure following the peel or with Fitzpatrick
skin types III and VI. This can be managed with a combination of 0.05% retinoic acid,
2.5% hydrocortisone cream, and 4% hydroquinone cream.
Hypopigmentation
One of the most severe complications of chemical peeling is hypopigmentation. This
is most likely because of phenol's ability to eliminate melanocyte's ability to produce
melanin. Hypopigmentation is much more readily noticeable when single facial subunits
are peeled rather than the whole face. This complication was more common in the past
when deeper peels such as the classic Baker formulation were used, as well as postoperative
occlusive dressing applications. Hypopigmentation is unfortunately irreversible, and
all patients who experience some level of this should be advised about the potential
need for makeup usage.
Conclusion
Phenol–croton oil chemical peels have withstood the test of time and are still considered
the standard against which other facial resurfacing procedures are judged. More recently,
the widely expanded knowledge of croton oil, and its various concentrations, has yielded
many options for specializing treatment for different facial subunits, skin types,
thicknesses, and so on. A strong familiarity with the fundamentals and techniques
of chemical peeling can result in predictable and excellent results.