Introduction to cosmetic dermatology

Abstract

Cosmetic procedures are becoming increasingly popular with dermatologists. They are used to reverse the effects of aging, to improve the quality of the skin, to augment facial structures, and to improve the patient's appearance in general. They can also be beneficial for certain dermatoses. We present an introduction to cosmetic dermatologic procedures, focusing on chemical peels, botulinum toxin injections, and the use of filler substances. Following this review, the reader should have the basic knowledge to consider training to perform such procedures safely and effectively, even if he or she has not done so previously. Several agents are available for chemical peeling, each with unique properties for different therapeutic effects. Superficial peels penetrate the epidermis only and include α-hydroxy acids, salicylic acid, low-strength trichloracetic acid (TCA), and Jessner's solution. These epidermal peels are used to treat mild photoaging and other epidermal dermatoses such as acne vulgaris and are generally performed with the use of a series of peels. Medium-depth peels, such as medium-strength TCA or combination peels that use a superficial and medium-depth agent, extend into the papillary dermis or upper reticular dermis. They can eradicate fine lines and wrinkles, improve color variation, eliminate some actinic keratoses, and correct textural irregularities. Higher-strength TCA and phenol induce deep wounding into the mid-to-deep reticular dermis. These deep peels can be used to help eradicate heavy wrinkles and lines due to chronic photodamage, but their use has largely been replaced by erbium and CO 2 laser resurfacing. Histologic studies have shown that peeling agents help alter the structure and content of the skin, increase production of collagen and glycosaminoglycans, eliminate solar elastosis, and normalize epidermal atypia. Complications are largely related to infection, pigmentary alteration, delayed healing, and scarring, but appropriate patient screening and prophylaxis can minimize their incidence. Botulinum toxin injections are used in dermatology for two main purposes: elimination or attenuation of dynamic lines and wrinkles on the face and neck and elimination or attenuation of sweating in the case of hyperhidrosis of the hands, axillae, and/or feet. With an excellent safety profile and proven efficacy, these are popular procedures for patients. The medication is a neurotoxin that works by temporarily inhibiting the release of acetylcholine. The administering physician must be familiar with pertinent anatomy with respect to muscles of facial expression, appropriate doses, and injection sites, all of which are covered herein. In addition to being an effective treatment by itself, botulinum toxin injections can be combined with other procedures such as laser resurfacing, filler substance injections, facelifts, blepharoplasty, etc, to prolong and improve the results. Filler substances are injected in or below the skin in order to replace lost volume or to increase existing volume. They are frequently used for the nasolabial folds, lips, and perioral area, but they can also be used more extensively, as is the case in pan-facial structural lipoaugmentation. Fillers are occasionally used in nonfacial areas as well, such as in aging dorsal hands or other areas of atrophy. A number of filler substances are available. The main classes of fillers are bovine collagen, human collagen, polysaccharide fillers, fat, synthetic fillers, and combination filler substances. Most filler substances are temporary in their effect, but some do persist in the skin forever. The treating physician must be familiar with proper selection, handling, location and depth of placement, longevity, costs, benefits, and risks of each substance that he or she uses. The necessary information is covered in this text. This text is intended to be a complete introduction to the above-mentioned cosmetic dermatology procedures. It includes aspects such as history and mechanism of action, but it really focuses on the clinical information necessary to be able to consider performing these procedures. It includes suppliers of products, precise descriptions of how to carry out the procedures, and clinical pearls to help achieve successful outcomes. Curr Probl Dermatol 2003;15:35-83.