AND CHEMICAL PEELS
SOURCE: Grand Rounds of the UTMB Department of Otolaryngology
RESIDENT PHYSICIAN: Ravi Pachigolla, M.D.
FACULTY PHYSICIAN: Christopher H. Rassekh, M.D.
DATE: January 8, 1997
SERIES EDITOR: Francis B. Quinn, Jr., M.D.
|Return to Grand Rounds Index|
Dermabrasion is an ancient concept. Egyptians used alabaster and pumice to remove blemishes and smooth the skin. Modern dermabrasion was credited to Kromayer who introduced motor driven knives to abrade the skin. In addition, he reported that wounds would heal without scarring if the injury did not penetrate the reticular dermis. Other researchers improved techniques, instrumentation and practices including the development of wire fraises, new skin anesthetics, and learning about the physiology of wound healing.
Sir Joseph Lister introduced Carbolic Acid (Phenol) to medicine in the late 19th century. Subsequent researchers used Phenol to treat acne scarring beginning in the early 20th century. Other chemical exfoliants were introduced later in the century. Baker and Gordon introduced the common formula for Phenol solution that became the gold standard for deep peels. Others have followed and adjusted ingredients in their solution and this has been followed with other solutions.
Aging is a dynamic process mostly caused by extrinsic causes. UV light exposure leads to many of these skin changes including increased skin roughness, increased mottled hyperpigmentation, increased loss of elasticity and increased wrinkling. Histologically, we see a thicker stratum corneum, a thinner epidermis, epidermal atypia, irregular melanin dispersion, decreased glycosaminoglycans, and abnormal appearing elastic fibers. Different classification systems exist from the Fitzpatrick classification system of skin types to the Glogau system for photoaged skin. These systems are useful when designing a skin therapy program but should not overshadow one's own clinical judgment. When referring to pigmentary abnormalities of the skin, it is useful to know whether the pigmentation is epidermal or dermal. Wood's light accentuates epidermal hyperpigmentation but deeper dermal hyperpigmentation becomes less obvious. Epidermal hyperpigmentation is easier to correct than dermal hyperpigmentation with either peels or dermabrasion.
Dermabrasion refers to the mechanical abrasion, in successive layers, of epidermis and upper dermis. This leaves behind the unaffected epidermal lining of the deeper adnexal structures (ie. pilosebaceous units) which regenerates the surface epithelium. After dermabrasion, it can take up to two weeks for the epidermis to completely regenerate and adhere to the underlying dermis. Other histologic changes after dermabrasion include vascular dilatation, a more uniform melanocyte distribution with decreased melanin production, increased fibroblast activity with collagen formation in parallel bundles that may increase the dermal-epidermal thickness by 2 - 3 mm. The full impact of dermabrasion on one's skin may not be apparent for a couple of months.
The major indications for dermabrasion are to smooth irregular surfaces such as those caused by acne, facial scars, actinic damage, burn scars, early rhinopyma, superficial traumatic tattooing and sometimes rhytids. It is important to note that the deeper the dermabrasion, the better the result, the longer the healing and an increased chance for scarring. Chronic active acne may also be treated although a full medical trial should be tried first for acne. For long linear scars, scar revision should be performed first followed by dermabrasion 4 - 6 weeks later. Dermabrasion is often used for shallow scars that are not too wide (<0.5 cm), not too long (< 1 inch), and not too deep. If scars are wide, deep, or long, scar revision should be performed first prior to dermabrasion. Also scars perpendicular to RSTLs should also be treated by scar revision first.
There are several reasons to avoid dermabrasion in some patients. Some patients have systemic diseases which prevent them from undergoing dermabrasion. These diseases would include uncontrollable bleeding disorders, HIV because of the aerosolization risk, other active infectious diseases, diseases causing epidermal atrophy, active Herpes, and cryoglobulinemia. Accutane (isotretinoin), in a group of compounds referred to as retinoids, causes a gradual decrease in the amount of pilosebaceous units of the skin and also inhibits collagenase, an enzyme responsible for collagen remodeling. Patients treated with Accutane have been known to develop irregular hypertrophic scarring after dermabrasion presumably as a result of decreased pilosebaceous units contributing to epithelial proliferation and decreased collagenase. For this reason, it is advisable to wait one to two years before performing dermabrasion on a patient who has taken Accutane. Caution should be used when performing dermabrasion on Asian and African American patients because of the hypopigmentation that results which is sometimes permanent. Dermabrasion is also avoided on areas of skin that lack pilosebaceous units such as the eyelids, lower neck, and upper chest. Dermabrasion should not be used for ice pick scars because of their deep pits; however, some newer pinpoint burrs can dermabrade shallow ice pick scars. Otherwise ice pick scars should be treated with other techniques including punch grafting. Patients who are prone to keloid formation and those with red, ruddy complexions should generally be avoided because of the risk of postoperative scarring and hyperpigmentation, respectively. Lastly, if there is suspicion of malignancy, dermabrasion should be avoided.
Patients should be aware of the limitations of dermabrasion, accept these limitations, and proceed forward. Patients should refrain from medications that interfere with pigmentation (ie. BCP's, Dilantin, other hormonal medications) for several months prior to and after dermabrasion. Patients should be explained the entire procedure beforehand and preoperative pictures should be taken. The pictures should be taken so that shadows come across the suface of the face and accentuate the facial scarring. Lab evaluation may include CBC, VDRL, HIV, and a hepatitis profile. Preoperatively, oral retinoids should be discontinued at least three months before the procedure. Also topical retinoids and bleaching agents (ie. hydroquinones) can be given prior to the procedure. Zovirax should be given to patients with history of fever blisters five days before the procedure; other authors recommend prophylactic Zovirax to all patients since at least one study has shown 7% of patients without prior history of herpes can have a herpetic outbreak post-procedure.
Surgical instruments for dermabrasion include, of historical interest, the use of sandpaper earlier this century. However, this was very painful, bloody, and sometimes led to silicone granulomas because of the silica particles embedding in the skin. This procedure was eventually discontinued. Other older instrumentation includes the rotating wirebrush. This instrument can be used effectively in the hands of an experienced practitioner producing a fast, even dermabrasion over the entire face. However, the wire brushes can inadvertently produce full thickness defects, actually produce microlacerations instead of abrading the skin, and cannot maneuver around the corners of the face. The newer diamond fraises are the instruments of choice, especially in inexperienced hands, due to the increased safety profile, easier control of depth of abrasion and no need for freezing of the skin. Different grits exists alongwith different head shapes. Skin freezing is a matter of personal preference as some practitioners have used this method for a long time whereas others prefer assistants holding the skin taut.
Patients should arrive the morning of surgery. Their face is prepped in the usual fashion with an antimicrobial solution and they may be given pain and sedation medications. Regional nerve blocks are then performed if necessary. Facial subunits are marked (right cheek, left cheek, periorbital, perioral, nose, and forehead) prior to the procedure. Microfoam tape is placed along the neck to prevent accidental freezing and dermabrasion of the neck. Ice cool packs are placed alternately on each side of the face to cool the face prior to freezing if one is planning to freeze the face. Different freezing solutions are available including Ethyl Chloride, Frigiderm, and Cryoesthesia compounds. Frigiderm is generally preferred since it is non-toxic, non-flammable, and non-irritating. Ethyl Chloride is flammable and irritating while the Cryoesthesia formulations are too cold and produce excessive tissue freezing leading to possible freeze burn and possible scarring. Next the solution is sprayed onto one subunit at a time usually starting with dependent subunits and working up. The solution is sprayed until a white frost forms and prevents indentation of the skin with your finger. Dermabrasion usually begins in the dependent subunits because this prevents blood from running down into your field. Next holding the dermabrader with the thumb along the shank allows you to dermabrade to an even depth. Start at the periphery of the subunit and work your way to the center. Dermabrade down to the level of the upper reticular dermis which usually occurs when the white fibers of the papillary dermis no longer appear in the wound and the blood vessels of the papillary dermis have disappeared. Dermabrade one skin subunit at a time then move on to the next one. Spot dermabrasion is generally avoided. A few cautions should be noted. Be careful when freezing or dermabrading over bony prominences (ie. skin over the malar eminence, chin bossing, frontal bossing, etc.) as the skin is thin and full thickness wounds may occur. Some surgeons dermabrade the cheek first where acne scarring is worst instead of starting in the dependent areas of the face. Dermabrasion should be feathered into the hairline and one to two cm below the mandible to hide any line of demarcation between dermabraded and nondermabraded skin.
Postoperatively, patients may take care of their wounds with moisturizers, lotions, wet packs, or biological dressings. The important point to be made is that moist occlusion of dermabraded areas leads to faster reepithelialization with fewer complications than does simple air drying without any moistening solutions. Dressings may include petrolatum impregnated Vigilon, Biobrane, or moisturizing ointments. If crusting is allowed to occur, epithelialization can be delayed for one to two days and the chances of scarring are increased. Patients are followed frequently for the next couple of weeks and are given analgesics and steroids. By two weeks, patients can usually resume their normal activities with the caveat to avoid sun exposure for several months. Complications will be discussed at the end since both chemabrasion and dermabrasion can have similar complications.
Chemical peeling, or chemical exfoliation, consists of the accelerated removal of the superficial skin layers by chemical cautery. Peels are described as superficial, medium or deep peels. Chemical peels induce epidermal growth and inflammation in the deeper layers of skin to create an organized framework of collagen in parallel rows instead of haphazardly. Peeling agents I will discuss include Phenol, trichloroacetic acid (TCA), Alpha hydroxy acids (AHAs), Jessner's solution and salicylic acid.
Indications for chemical peeling include wrinkling, blepharomelasma, actinic keratoses, pigmentation abnormalities, superficial acne scarring and other miscellaneous reasons. Contraindications to chemical peels are similar to those for dermabrasion although specific chemicals have specific contraindications which will be discussed later. Also, deep acne scarring is not suitable for chemical peeling because of the further scarring risk and this should be treated with dermabrasion instead.
Chemical peeling should be performed after adequate preoperative preparation of the skin. This would include adequate sun protection, topical Retin-A use for weeks prior to the peel (mild irritation and erythema may result), possibly AHA's (partially neutralized glycolic acid appears to be the best) and bleaching agents. This allows a thinner stratum corneum, thicker epidermis, increased glycosaminoglycans, and possibly increased collagen deposition.
Phenol solutions are the oldest solutions used for chemical peeling and are generally used for deep peeling, ie. peeling down to the level of the reticular dermis. The most commonly used phenol formula is the Baker Gordon formula which contains croton and septisol in addition to Phenol. Patients first wash their face with alcohol soaps to remove oils (oils impede the phenol solution) and acetone is used to wipe off any remaining oils. Pain and sedation is given if needed. Then the solution is applied with applicators to the face until a white frost develops. This indicates that the solution has reached the desired depth in the dermis and no more solution should be applied. A few notes need to be made about phenol. Phenol is cardiotoxic and neurotoxic. Therefore, patients with cardiac abnormalities should not undergo phenol peeling. Also, since phenol is absorbed into the body and excreted by the kidney, any renal dysfunction may lead to build-up of phenol and its associated toxicities. When performing a full face peel, patients need IVF, cardiac monitoring, and the peel should be spaced over an hour or so to prevent build-up of phenol in the body. A full face peel should be done one facial subunit at a time. Baker's solution contains Croton which itself irritates the epidermis allowing penetration of the Phenol into the dermis causing keratolysis. Stronger concentrations of Phenol can be keratocoagulating thus limiting the penetration of Phenol and paradoxically leading to a more superficial peel than with a lower concentration phenol solution. The phenol peel is a true chemical peel leading to desquamation, crusting, erythema, and swelling over one to two weeks. Patients should be aware of this. Postoperatively, the wound is kept moist with petrolatum or moisturizers, frequent gentle washing is done, and crust formation is prevented. Taping is avoided as it may increase scarring. Other postoperative care is similar to dermabrasion.
Trichloroacetic (TCA) peels can be used to create superficial, medium, or deep peels although they are most commonly used for medium peels. TCA is inexpensive, stable, needs no neutralizing agent and is nontoxic. Stronger concentrations may be used for deep peels but significant more side effects can occur including hypopigmentation and scarring that is worse than phenol. The medium depth peel will usually penetrate into the epidermis and papillary dermis. The solution is applied similar to the phenol peel with the caveat that cumulative solution can become additive and lead to a deeper peel. TCA is a chemical cauterant that creates a white frost when applied to the skin. The degree of frosting usually determines the level of the peel. Postpeel care is similar to dermabrasion. Prevention of crusting is the most important idea and this can be accomplished with adequate moisturizing solutions.
Superficial peels include Jessner's solution, alpha hydroxy acids, and others. Jessner's solution contains resorcinol, salicylic acid, and lactic acid. This superficial peel creates a great deal of exfoliation and rarely penetrates deeply so it is safe. However, drawbacks include the potential salicylic acid toxicity and resorcinol toxicity. This solution also stings greatly. AHA's are organic acids that are inflammatory to the skin. In comparison to Jessner's solution, it can tend to be uneven, requires neutralizing alkaline agents, does not sting and has no chance for systemic toxicity. Generally these superficial peels need to be repeated and yet still do not match the effectiveness of one single medium or deep peel. However, they have excellent safety profiles so complications are quite uncommon. Healing time is shortened and patients can return to work immediately but the improvement in skin contour may not be as significant as with deeper peels. These superficial peels can also be used in conjunction with deeper peels decreasing the amount of each agent and possibly improving skin results.
Complications from chemical peels and dermabrasion are many and varied. Hypo, hyperpigmentation, scarring, herpetic activation, bacterial infection, and milia may occur. Hypopigmentation is a natural occurrence (not really a complication) seen with skin exfoliation. The deeper the dermabrasion or chemical peel, this increases the chance that melanocytes in the basal layer will be killed. Also the remaining melanocytes produce less melanin than before although this melanin may be more evenly distributed. Again caution is the best prevention. Dark skinned patients should be aware of this beforehand since this hypopigmentation is entirely unpredictable in severity. Post-inflammatory hyperpigmentation also can occur but this usually subsides after several weeks. It can be exacerbated by sun exposure so patients are naturally told to avoid the sun. This can be treated with Retin-A and hydroquinone. Retin-A disperses melanin throughout the epidermis so this decreases pigmentation and hydroquinone inhibits tyrosinase which converts tyrosine to melanin. Inflammation, pruritis, and erythema can be treated with topical steroids which usually arrests these problems. Topical steroids should not be used too frequently as they may lead to telangiectasia and atrophic skin. Herpetic outbreaks should be treated with acyclovir and no residual scarring should arise. Again pretreatment with acyclovir 3-5 days prior to and two weeks after the procedure will usually prevent any herpetic outbreak in a patient with a known history of herpes. Scarring can result from too deep a peel or dermabrasion and this can be treated with topical steroids. Rarely, intralesional injection of scars may be needed. The association of Accutane with scarring was mentioned earlier. Infections are extremely rare, usually caused by patient noncompliance. This can be treated with appropriate antibiotics. Milia, small epidermal inclusion cysts, can occur but usually resolve on their own after several weeks. If they persist, a needle may be used to unroof these cysts. No scarring should occur.
Chemical peels and dermabrasion can be used in conjunction with other facial plastic surgery. Generally, there should be a three to sixth month window period between the two procedures. This is because if dermabrasion or chemical peeling is performed too soon to a rhytidectomy or blepharoplasty, scarring may result. The undermined skin flaps are more prone to scarring after dermabrasion or chemical peels.