Dr. Tzermias Christopher GREECE What are the long and short benefits of Retinoic Acid, AHAS and Chemical Peels Dr. Tzermias Christopher GREECE

Tretinoin - Retinoic Acid The most consistent and significant improvement within 4-10 months of therapy are: Skin texture Mottled hyperpigmentation Fine wrinkles The use of 0.05% and 0.1% tretinoin cream for 6 months leads to an increase in epidermal and granular layer thickness.

Complication The most important complication of retinoic acid is its tendency to cause skin dryness, therefore new emollient formulations have been produced. Clinical improvement of fine wrinklin Histologically After 24 weeks of use, reversal of stratum corneum compaction and epidermal and granular thickness is observed After 48 weeks of use melanin content decreases and epidermal mucin increases

Alpa Hydroxy Acids ( AHAS ) AHAs are linear organic carboxylic acids with an attached hydroxyl group and can be derived in natural foods; hence the common name, fruit acids. Glycolic acid ( in sugar cane) the simplest and most popular one is available in concentrations ranging from 5% to 15%. Higher concentrations of this acid are used in chemical peels. Other fruit acids are: Lactic acid from sour milk Citric acid from citric fruits Tartaric acid from grapes Malic acid from apple

The increased skin thickness is attributed to increased synthesis of: The use of AHAs has been shown to reverse histologic sings of photoaging by: Increasing epidermal thickness Reversing basal cell atypia Dispersing melanin pigmentation and Normalising the rate pattern of the dermoepidermal junction The increased skin thickness is attributed to increased synthesis of: Glycosaminoglycans Collagen Elastic fibers

Chemical peels are categorized into The process of chemical peeling involves the application of a caustic agent on the skin to produce a controlled, partial-thickness inlury. Chemical peels are categorized into Superficial peels Medium depth peels Deep depth peels

Superficial Peels Superficial peels penetrate the epidermis down to the dermal- epidermal junction Some superficial peeling agents are: Jessner’s solution Glycolic acid at concentrations of 20% to 70% Trichloacetic acid at concentrations of 15% to 35% Obagi “blue peel”

Jessner’s solution Jessner’s solution is a combination of Resorcinol Salicylic acid Lactic acid In an alcohol solution Triple layer application produces stratum corneum separation with upper intraepithelial and intercellular edema.

Glycolic acid Glycolic acid at concentrations of 20% to 70% Glycolic acid Glycolic acid at concentrations of 20% to 70%. The effect of the peel depends on the length of time it is left on the skin . Therefore it has to be neutralized either with water of sodium bicarbonate to prevent deeper dermal penetration Usually are performed in a series of 4 to 6 treatments at 1 to 6 week intervals in order to improve Skin shallowness Dyspigmentation Fine wrinkles Mild photodamage For the last two an initial application of 70% unbuffed glycolic solution is recommended for a duration of 4 to 8 min.

Trichloacetic Acid TCA CAUSES Necrosis Exfoliation of normal and actinically damaged cells Percipitation of epidermal proteins Therefore application of TCA causes: Transient frosting Erythema A great advantage of TCA is that it is nontoxic systematically and is neutralized by serum in superficial dermal blood vessels.

Obagi “blue peel” Obagi, “blue peel” contains a non ionic base with glycerin and saponine in order: To slow the rate of TCA action and To gauge the depth of peel A light blue endpoint signifies exfoliation to the stratum corneum while a dark blue endpoint denotes coagulation to the basal layer of the epidermis Superficial peels are desirable because: All skin types can be treated Have a minimal recovery time Minimize serious adverse sepuale

Medium Depth Peels Produce an injury depth down to the upper dermis and are best in use in: • Actinic keratoses Dyschromia Mild wrinkling

TCA 40% to 60% TCA 60% to 75% can cause: Epidermal necrosis Edema Homogenization of the papilary dermis Sparse lympholytic infiltration in the midretieular dermis within 3 days after application TCA 60% to 75% Recommended only for spot treatment of localized keratoses 50% of TCA may be applied either: in a rapid fashion over the entire face without overcoating of In a slow controlled manner to each cosmetic unit Eyelids are peeled with 20% to 35% TCA

In an attempt to decrease the risk of complications ( hypochromia) a superficial agent is used initially. After decreasing the skin with acetone either dry ice or Jenssen’s solution can be applied to initiate an epidermal injury. This then enables the 35% TCA to penetrate more readily. These two deepest medium depth peels dry ice and TCA are not recommended for skin types V and VI due to the visit of hypopigmentation. A newer combination is the use of 70% unbuffered aqueous glycolic solution to soapclean skin without prior decreasing with acetone. Left on for 2 min this solution causes epidermolysis enabling deeper penetration of subsequent 35% TCA solution application.

Deep Peels Baker’s formula Indication for their use include: Deep rhytides secondary to photodamage Severe or extensive actinic keratoses Baker’s formula Baker’s formula is the most common one. It is composed of mixture containing: 3ml 88% phenol US8 3 drops croton oil (augments phenol penetration causing epidermolysis) 8 drops Septisol (increases surface tension and slows the penetration of phenol) 2ml distilled reaction

Phenol The reaction following application of phenol is characterized by: Keratocoagulative necrosis of the epidermis extending into the papillary dermis A marked inflammatory reaction Epidermal regeneration begins within 48h and is completed within 1 week Dermal regeneration takes longer than the epidermal and is characterized by rigid, compact collagen in the upper dermis replacing the disorganized collagen seen in elastosis.

Deep phenol peeling may lead to irreversible hypopigmentation and therefore is advised not to be used on skin types V and VI. Cardiac arrythmias sometimes severe

Complications Of Chemical Peels Adverse sequelae following superficial and medium depth peels are usually minor and reversible including prolonged erythema and post inflammatory hyperpigmentation. Hypertrophic scarring can occur, rarely and can be managed by the use of anyone or a combination of therapies including topical or intracesional steroid, silicone gel sheeting and pulsed dye laser irradiation.    3t is a common practice to pretreat patients with tretinoin or/and hydroquinone for 4 to 6 weeks prior to a chemical peel. This regimen decreases the stratum corneum thickness ensuring a more uniform response following the application of the peeling solution.