j. Cosmet. sci., 51, 39-71 (January/February 2000) Papers Presented at the 1999 Annual Scientific Meeting December 9-10, 1999 New York Hilton New York, NY 39

40 JOURNAL OF COSMETIC SCIENCE AGING SKIN: A DERMATOLOGIST'S PERSPECTIVE Elyse S. Rafel, M.D. Stony Brook DermatologyAssociates, P. C., East Setauket, NY 11733 Aging skin is divided into chronologic (intrinsic) aging, which is due to the passage of time and photoaging (extrinsic), which is usually caused by chronic sun exposure. Tanning beds, phototherapy and smoking sometimes play a role in the etiology of extrinsic aging. The clinical features of intrinsically aged skin include fine wrinkles, pallor, smoothness, dryness and laxity. Photoaged skin exhibits fine and coarse wrinkles, roughness, leathery or atrophic skin, yellowness and dyspigmentation. There are several common benign neoplasms associated with intrinsic aging including seborrheic keratoses, cherry angiomas, sebaceous hyperplasias and skin tags. Actinic keratoses, basal cell carcinomas, squamous cell carcinomas, and malignant melanomas are the premalignant and malignant neoplasms associated with photoaging. There are various methods employed by dermatologists in clinical practice as well as by pharmaceutical and cosmetic companies to quantify aging skin. A photonumeric scale involves using standard photographs of five patients representing grades of photodamage. The patient is then compared to these photographs and appropriately graded. A descriptive scale, which evaluates wrinkles, dyspigmentation and yellowing is often used by pharmaceutical companies to assess photodamage. A colorimeter and UV camera are sometimes utilized to evaluate dyspigmentation. Optical profilometry, pulsed A-scan ultrasound, uniaxial extensometer and image analysis of high-resolution photography are methods used to quantify wrinkles. The Fitzpatrick skin type system categorizes patients according to their ability to bum and tan. Furthermore, it predicts their susceptibility to photoaging and degree of risk for complications after surgery. Various classification systems are also employed to quantify the degree of photodamage and delineate guidelines for treatment. The age of onset of photoaging depends on the skin type and sun exposure history. The third to fifth decade is the usual onset in Caucasians however, in fair skinned individuals, the onset may be prior to age twenty. Conversely, the onset may be delayed or clinically inapparent in darker skinned races. Intrinsic aging usually has a minor impact on appearance. However, photoaging often plays a major role, especially concerning social and occupational issues. Since our self-esteem is often partially related to our body image, it is important to have effective ways to prevent and treat aging skin. Prevention of aging skin involves the avoidance of sun and tanning parlors, use of protective clothing and avoidance of smoking. Sunscreens are the mainstay of adjunctive treatment. They should be broad spectrum with at least an SPF of 15. Lifelong, daily use is essential. Sunscreens should be applied liberally approximately one half-hour prior to going outside. The two classes of sunscreens are chemical and physical. Chemical sunscreens include PABA and its derivatives, salicylates, benzophenones, cinnamates, dibenzoylmethanes, and anthranilates. Physical sunscreens include titanium dioxide, zinc oxide and red petrolatum. Future sunscreens should have broader spectrum coverage, better substantivity and quicker absorption. An ideal sunscreen should cause less contact dermatitis, be more cosmetically elegant and be easier to apply the necessary amount. Topical retinoids play a major role in the treatment of photoaging. The efficacy and safety of tretinoin for photodamage has been documented by several authors in vehicle-controlled, multicenter, double-blind clinical trials. Retinol is a popular ingredient in antiaging OTC products however, double-blind, placebo- controlled studies are needed to determine their efficacy. Alpha hydroxy acids, especially glycolic acids are important antiaging products. The beta hydroxy acid, salicylic acid, is mainly used for acne, but it is sometimes used for photoaging. The polyhydroxy acid, gluconolactone, is reportedly less irritating than alpha hydroxy acids.