International Journal of Cosmetic Surgery

by Yoram Fintsi, MD
Department of Pathology, The Wolfson Medical Center, Holon, Israel
and Sackler School of Medicine, Tel-Aviv University

Exoderm is a newly developed chemical deep-depth peeling method that has been shown to exhibit excellent results in the treatment of a broad spectrum of aging-skin defects. The new formula is devoid of common undesired effects, such as cardiac arrhythmias, long lasting erythema, depigmentation, and scar formation. Our experience with more than 4000 patients attests to the safety of the method. Exoderm compares favorably with other surgical and nonsurgical procedures for facial rejuvenation.

Chemical peeling has been used for over half a century and has gained widespread use over the past decade. A variety of chemicals are used and the results of the procedure depend on a multitude of factors, mainly the chemical agents used and the peeling technique. Overall, the best results are obtained by deep-depth peeling using phenol-containing solutions.
The major disadvantages of the classical phenol peeling methods, however, are the potential systemic and local complications. Exoderm is a modified, buffered, phenol-containing solution that exerts controlled dermal penetration and limited systemic absorption, and is thus devoid of the complications associated with conventional phenol peels. In this article, we report on our experience with Exoderm.

The basic formula for Exoderm was developed in 1986 and refined in 1990 by a group of chemists, plastic surgeons, and dermatopathologists, with the aim of attenuating the irritability of phenol, as well as minimizing the systemic and local complications associated with the classical phenol-peel solutions, while maintaining the beneficial effects of deep-depth peeling. This goal was achieved by modifying the chemical constituents of the solution to include a variety of oils, alcohols, and buffer substances that enhance the epidermal penetration by causing liquefaction and simultaneously limit the vascular absorption of the chemical agents at the dermal-epidermal junction.
The Exoderm formula selectively melts the superficial layers of the skin, resulting in liquefaction of those layers while partially preserving the melanocytes in the basal layer. This limited exfoliation induces regeneration of the skin and stimulates the formation of new collagen and elastin fibers in the subepidermal layer (Grenz zone). The ultimate result is a "tightening" effect that eliminates medium and deep rhytides as well as a variety of discoloration conditions and precancerous lesions, providing a long-lasting rejuvenation effect. Indications for the Exoderm method include wrinkled skin, cutaneous pigmentation such as freckles, solar lentigo, and melasma, acne scars and deep dermal pits, and precancerous lesions such as solar keratosis and early phases of basal-cell carcinoma.

The Exoderm solution is composed of the following components: phenol liquid 91% (1 cc); phenol crystalized 99% (1 cc); distilled water (0.5 cc); mixture of alcohol, olive oil, glycerine oil, and sesame oil (0.5 cc); croton oil (2 drops); resorcin (0.3 cc); soap (10 drops); citric acid (0.2 cc); and buffer tris. Each component is essential for achieving optimal results and maximal safety. The chemical wounding agents are liquid phenol, crystalized phenol, resorcinol, and salicylic acid. The oils are croton oil, olive oil, glycerine oil, and sesame oil. The adjuvant components are distilled water, liquid hexachlorophene (Septisol), ethanol (ethyl alcohol), and buffer tris solution.

One day prior to the procedure the patient is advised to avoid the application of any cosmetics or eye liners. On the day of the procedure the skin is washed with soap, rinsed with water, and then scrubbed with either acetone or ether on gauze pads for degreasing of the skin and removal of debris.

The procedure is performed with the patient under i.v. sedation with beatril, prothiazine, and morphine sulfate (5-15 mg) or derivatives at doses titrated to the elimination of the burning sensation. Throughout the procedure the patient is awake and responsive, and is attached to a pulse oximeter.
The Exoderm solution is applied with a cotton applicator and rubbed onto the skin and into all rhytides and skin folds starting at the forehead 2 mm behind the hairline. Gradually the whole forehead is covered, progressing to other cosmetic units such as periorbital, cheeks, perioral, and nose. The most painful area is the eyelid; in this area an almost dry applicator is used up to the margin of the eye lashes at both angles. In this periorbital region the solution is applied in the direction opposite that of the eyebrows. Special attention should be given to the crow's-foot wrinkles and the perioral region. The solution is vigorously rubbed into the unfolded rhytid. In order to avoid a periorbital halo, the solution must be applied about 1 mm beyond the vermilion. The lower margin of application should be the earlobes and 2 cm below the mandibular line.
The solution will produce a white blanching, or frosting, of the skin. As soon as frosting is seen, the area is rubbed dry with a dry cotton pad. The frosting disappears in a few minutes and is replaced by a red-grayish color. The skin becomes edematous with puffy eyelids and creates a "leathery" sensation on touching. The procedure is performed twice in all facial areas, except for the deep folds and rhytides, which are treated three to four times. The total amount of solution does not exceed 3 mL.
Following the procedure, the skin is taped by an impermeable, hypoallergenic, zinc-oxide- based plastic tape which is applied in strips of 3-4 cm in length in an overlapping fashion. The lower margin is taped up to the osseous part of the mandible; the area beyond remains untaped. The tape mask is easily removed after 18-24 hours, exposing an edematous and pink skin. Brownish liquid from the macerated epidermis is removed by a dry cotton applicator.
Immediately thereafter, the face is covered by a bismuth subgalate powder, which acts as a protective antiseptic and regenerative mask and remains for a period of 7 days.
On the eighth day, vaseline is applied to the rigid powder mask in order to soften and detach the mask from the newly formed skin.

A fter the procedure, the patient is advised to use water-based lotion creams 4 to 5 times a day and sunscreen creams with an SPF of 15 to 19. The erythema gradually resolves over 2 to 6 weeks in the majority of cases. During this period, makeup is encouraged for blending face and neck skin color. In cases of olive skin patients (Fitzpatrick skin type 3 or 4), the application of Kligman cream is recommended for the prophylaxis of hyperpigmentation.

The initial 558 patients were monitored during the procedure by a cardiac rhythm monitor and had pre-and postprocedure laboratory screenings. Following careful assessment of the results demonstrating excellent safety of the Exoderm formula, these precautionary measures were deemed unnecessary and were subsequently abandoned, except for pulse oximetric monitoring.
Since then, more than 3000 patients have been exposed to the procedure and have confirmed both the safety of the formula and the high degree of patient satisfaction. The following is a summary of patient characteristics: All patients were females, with an average age of 54 years, ranging between 19 and 85 years. Most patients had Fitzpatrick skin type 2 or 3.Sixty-two of the 558 females had previously undergone surgical face- and/or neck-liftng. Five hundred thirty-two patients had multiple wrinkles in various areas of the face (perioral, 439; periorbital, 346; deep expression lines, 528; gravity lines at the cheeks, 419). Pigmentary disorders (freckles, senilelentigo, melasma, or postacne) were observed in 430 females. The predominant indications for the procedure in 59 patients were acne scars or dilated pits either with or without associated wrinkles. Precancerous lesions like solar keratosis or superficial basal-cell carcinoma were seen in 63 females.
During the procedure in 36 patients, a sinus tachycardia up to 120 beats/minute was noted that was asymptomatic and related to the burning sensation on application of the formula, especially at the upper and lower eyelids. Subsequent to the procedure, 21 patients developed a transient temperature of up to 38° C, which was treated by paracetamol and resolved within 24 hours. A burning sensation, usually on the third postprocedure day, was experienced by 186 females, possibly due to the edema and irritation of nerve endings. This sensation was frequently associated with slight depression, which resolved within 24 hours. Pruritus, probably secondary to the healing process, was noted in 130 patients on the seventh and eighth days.

No permanent complications, such as scars, have been observed. Homogenous lightening of the skin color (apricot color), however, was frequently seen and was well accepted and tolerated by the patients. Transient complications were related to the demarcation line between the submandibular zone and the neck region, especially in patients with darker skin. This condition disappeared gradually over a period of 6-8 weeks with the applications of bending creams. Occasionally, hyperpigmentation developed, particularly in patients with Fitzpatrick 3 or 4 degree of skin (47 patients ). This can be avoided by using prophylactic bleaching creams based on retinoic acid, hydroquinone, and dexamethasone.
Persistent erythema that lasted for more than two months was observed in four patients. During that period, the erythema may be aggravated by conditions related to vasodilation. In seven patients, herpes simplex labialis eruption occurred; in one of them a diffuse dermatitis herpetiforme developed and was treated by acyclovir and topical application of bismuth subgalate, which caused total resolution without sequellae. There were no bacterial infections in any of the treated patients and therefore no prophylactic use of topical or systemic antibiotics is indicated.

Follow-up up to 6 years has revealed satisfactory results. Based on a scale of 1 (disappointment) to 10 (high degree of satisfaction) , patients were asked to express their degree of satisfaction 12 to 20 weeks after the procedure. The average score was 8.6. In approximately 30% of patients, a local touch-up was performed, i.e., application of the liquid solution at a single wrinkle or at a newly formed pigmentary spot. In only 21 cases (20 with acne and one with hyperpigmentation) was a repeated application of larger areas, mostly temples, cheeks, and chin, the preferred sites of acne scars, necessary.

Exoderm is a newly developed chemical exfoliation method that combines safety and efficacy with simplicity of application. The procedure results in a high degree of patient satisfaction and sustained benefits.
In comparison to conventional phenol-based peels there are three important advantages: (1) The oily components of the liquid formula guarantee a delayed absorption of the acid ingredients (especially phenol) into the dermoepidermal vascular bed and, therefore, eliminate the probability of toxic effects (cardiac arrhythmias). In none of our monitored cases have we observed any cardiac arrhythmias. Occasional sinus tachycardia may occur, and is related to the burning sensation experienced usually during application of the solution in the periorbital region (upper and lower eyelids). (2) Conventional phenol peel are known to occasionally cause hypertrophic scars and keloids at treated areas. The pathogenesis of these scars is related to the penetration of the solution into the deeper reticular dermis, thus stimulating uncontrolled overgrowth of collagen fibers. The adjustment of the Exoderm formula to the pH of the upper reticular dermis using buffer solutions creates "auto-blockage" at the upper reticular dermis and thus abolishes the risk of scar formation. (3) An important advantage for the patient is the relatively short period of recovery. Due to the combination of three potent chemical agents (phenol, citric acid, and resorcin), which results in a rapid breakdown of the tide bonds of the epidermal cells, the liquefactoin phase is completed within 24 hours, while the regenerative phase (reepithelization) is accelerated by the bismuth subgalate powder and completed within 7 days.

Superficial chemical peels with alfa-hydroxy acids do not alter rhytides to any significant degree. Medium-depth chemical peels, such as 35% trichloacetic acid with Jessner's solution or solid CO2, improve textural irregularities and very superficial wrinkling, but have no effect on clinically visible wrinkling. Deep chemical peels with Baker's phenol solution are effective for removing even the deepest rhytides, but most patients are left with permanent hypopigmentation or depigmentation, and there is also a significant risk of scarring. Furthermore, the postoperative course is usually painful, and erythema lasting more than 6 months is common.
Dermabrasion is technically more difficult and more traumatic to the patient and is mainly used in the treatment of postacne scars and deep pits. The procedure is associated with a considerable risk of bacterial infections and hypopigmentation.
Carbon dioxide laser resurfacing is a relatively new method that has raised great interest and expectations among physicians and patients alike. The method achieves results similar to those of medium-depth chemical peels, i.e., it does not eliminate deep rhytides and does not create the "lifting effect" typical for deep chemical peels such as Exoderm. The advantages of laser resurfacing are simplicity and high degree of safety, although the incidences of postinflammatory hyperpigmentation and erythema are relatively high. Cases of delayed hypopigmentation and hypertrophic scarring are also beginning to accumulate.

Exoderm is a newly developed deep chemical, phenol-based peeling method that compares favorably with other surgical and nonsurgical procedures for skin rejuvenation and face-lifting. It is a safe and cost-effective method that guarantees excellent results and a high degree of patient satisfaction.

The author is grateful to Heschi H. Rotmensch, M.D., for his professional advice and invaluable contribution to the generation of this manuscript.

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Exoderm - A Novel, Phenol-Based Peeling Method Resulting in Improved Safety

Exoderm -
A Novel, Phenol-Based Peeling Method Resulting in Improved Safety