Combination therapy in clinical and cosmetic dermatology: the marriage of device and drug

Journal of Drugs in Dermatology, Sept-Oct, 2004 by Mark Steven Nestor

Abstract

The first generations of lasers used in clinical and cosmetic dermatology achieved their effects by means of epidermal and dermal ablation. While effective in removing some of the stigmata of photodamage including pigmentary changes and rhytides, vascular abnormalities associated with such conditions as melasma and rosacea, were not sufficiently effective. The new generation of laser and non-laser light devices (eg. intense pulsed light or IPL) offer excellent results in the management of clinical and cosmetic conditions, including significant changes in improvement in vascular conditions such as rosacea and actinic damage and stimulating dermal collagen production, without significant injury to the epidermis. The combination of light therapies and topical agents adds to the efficacy of these procedures, particularly in post-procedural maintenance. Light-based therapies have been an important addition to the anti-acne armamentarium as they are effective and do not add to the increasing bacterial resistance problem.

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Introduction

Over the past decade, lasers and non-laser light-based therapies have become increasingly popular in dermatology both for the management of clinical conditions and for cosmetic procedures and cutaneous rejuvenation (1,5). The first generation of these devices included several types of ablative lasers, which achieved their effects via epidermal ablation and heat-wounding of the dermis. The thermal destruction caused by the procedures usually required a prolonged recovery period during which time the skin had to be continually dressed and treated with the attendant risks of infection. However, they were effective in producing new collagen synthesis and improving signs of photoaging, including pigmentary changes and rhytides. Building on knowledge gained with these earlier procedures, a variety of non-ablative technologies has been introduced in recent years. These newer procedures are able to target pigmentary and/or vascular abnormalities and induce new collagen synthesis without significant epidermal and dermal wounding and postoperative healing considerations that pertained with ablative resurfacing techniques. Actinic damage, rosacea, melasma, and acne-clinical conditions with a cosmetic overlap and significant effects on many patients' psychosocial functioning respond to these new procedures with dramatically less recovery time.

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Physicians and patients have embraced these new therapies and new technologies, yet the expectations of each continue to rise. Patients continue to seek cosmetic and clinical improvement with less "down time" and less expense, while physicians are striving to provide care for these overlapping areas of skin disease, photodamage and cosmetic enhancement with greater efficacy and safety. One of the most important advances in the effort to achieve these ends has been increased use of the combination of newly developed non-ablative lasers, non-laser light sources and pre-existing gold standard topical medications.

Examples of these non-ablative technologies include intense pulsed light (IPL), pulsed dye laser (PDL), 1320 nm neodimium doped yttrium aluminum garnet (Nd: YAG), long-pulsed erbium substituted: yttrium aluminium garnet (Er:YAG), radiofrequency (RF), light-emitting diodes (LED) and photodynamic therapy (PDT) using light of varying wavelengths. The U.S. Food and Drug Administration (FDA) has now approved the IPL for the treatment of rosacea and hyperpigmentation and the 1320 and 1440 nm Nd:YAG lasers and blue light are approved for the treatment of acne. New indications are being added continually.

The pharmaceutical treatments that are being used in conjunction with these devices include topical 0.75% metronidazole (MetroCream[R], MetroLotion[R]) and oral metronidazole (MetroGel[R]) for rosacea, retinoids for acne and actinic damage (Differin[R], Retin-A[R], Avage[R], Avita[R], Renova[R]), and the prescription triple-combination cream (Tri-Luma[R] Cream) based on the original Kligman and Willis formulation for melasma and other pigmentary disorders (6). Newer agents, such as the topical 2% mequinol/0.01% tretinoin solution (Solage[R] Topical Solution) for solar lentigines, botulinum toxin (Botox[R]) and an increasing array of fillers for expression

lines and rhytides (Restylane[R]) are all important components of this new combination armamentarium.

Skin Damage and Photorejuvenation

Three types of photodamage have been identified (1,7). Type A damage may result from UV-related photoaging and other environmental causes such as infrared damage, rosacea, melasma, post-inflammatory hyperpigmentation (PIH) or laser resurfacing. Lesions include telangiectasias, erythema and flushing associated with rosacea, lentigines, ephelides and the pigmented plaques of melasma.

Type B damage consists of dermal and epidermal structural changes caused by the effects of photodamage on collagen and connective tissue. Lesions include rhytides, expression lines, elastotic changes and large pores.