Camile L. Hexsel

Impact of Long-Wavelength UVA and Visible Light on Melanocompetent Skin

The purpose of this study was to determine the effect of visible light on the immediate pigmentation and delayed tanning of melanocompetent skin; the results were compared with those induced by long-wavelength UVA (UVA1). Two electromagnetic radiation sources were used to irradiate the lower back of 20 volunteers with skin types IV-VI: UVA1 (340-400 nm) and visible light (400-700 nm). Pigmentation was assessed by visual examination, digital photography with a cross-polarized filter, and diffused reflectance spectroscopy at 7 time points over a 2-week period. Confocal microscopy and skin biopsies for histopathological examination using different stains were carried out. Irradiation was also carried out on skin type II. Results showed that although both UVA1 and visible light can induce pigmentation in skin types IV-VI, pigmentation induced by visible light was darker and more sustained. No pigmentation was observed in skin type II. The quality and quantity of pigment induced by visible light and UVA1 were different. These findings have potential implications on the management of photoaggravated pigmentary disorders, the proper use of sunscreens, and the treatment of depigmented lesions.

Effects of Visible Light on the Skin

Electromagnetic radiation has vast and diverse effects on human skin. Although photobiologic studies of sunlight date back to Sir Isaac Newton in 1671, most available studies focus on the UV radiation part of the spectrum. The effects of visible light and infrared radiation have not been, until recently, clearly elucidated. The goal of this review is to highlight the effects of visible light on the skin. As a result of advances in the understanding of skin optics, and comprehensive studies regarding the absorption spectrum of endogenous and exogenous skin chromophores, various biologic effects have been shown to be exerted by visible light radiation including erythema, pigmentation, thermal damage and free radical production. It has also been shown that visible light can induce indirect DNA damage through the generation of reactive oxygen species. Furthermore, a number of photodermatoses have an action spectrum in the visible light range, even though most of the currently available sunscreens offer, if any, weak protection against visible light. Conversely, because of its cutaneous biologic effects, visible light is used for the treatment of a variety of skin diseases and esthetic conditions in the form of lasers, intense pulsed light and photodynamic therapy.

Randomized Control Trial for the Treatment of Hidradenitis Suppurativa with a Neodymium‐Doped Yttrium Aluminium Garnet Laser

BACKGROUND Hidradenitis suppurativa (HS) is a chronic suppurative condition for which there is limited efficacy of medical and surgical treatments. OBJECTIVE To assess whether the 1,064‐nm neodymium‐doped yttrium aluminium garnet (Nd:YAG) laser is an effective treatment for HS. MATERIALS AND METHODS Prospective, randomized, controlled study for patients with stage II to III HS disease (n=22). A series of 3 monthly laser sessions were performed. Treatment response was measured before each laser session and 1 month after the completion of laser treatment (HS Lesion, Area, and Severity Index (HS‐LASI) scale). A modification was made to include symptoms (erythema, edema, pain, and purulent discharge; modified HS‐LASI, 0‐3 scale). RESULTS The percentage change in HS severity after 3 months of treatment was –65.3% over all anatomic sites, −73.4% inguinal, −62.0% axillary, and −53.1% inframammary. For all anatomic sites combined and each individual anatomic site, the change in HS severity from baseline to month 3 was statistically significant at the treated sites (p<.02 for modified HS‐LASI and HS‐LASI) but not at the control sites (p>.05 for modified HS‐LASI and HS‐LASI). CONCLUSIONS The long‐pulse Nd:YAG laser is effective for treatment of HS. The effectiveness of Nd:YAG laser, a hair epilation device, supports the primary follicular pathogenesis of the condition. The authors have indicated no significant interest with commercial supporters.

A validated photonumeric cellulite severity scale

Background  With recent advances in the treatment of cellulite and localized fat, a comprehensive objective method of measuring cellulite can be potentially useful, especially since important morphological aspects of cellulite are not part of the current classification.

Current sunscreen issues: 2007 Food and Drug Administration sunscreen labelling recommendations and combination sunscreen/insect repellent products

The Food and Drug Administration (FDA) regulates sunscreens as over-the-counter drugs. This article describes sunscreen actives available in the United States, new developments available elsewhere, and the amendment to the FDA 1999 sunscreen monograph, released on August 27, 2007, which proposes a new grading system for ultraviolet B protection, a cap of the sunburn protection factor to 50+, and a 4-star grading of ultraviolet A protection. In addition, current data on combination sunscreen and insect repellent products are discussed. Application of a combination product too frequently poses the risk of insect repellent toxicity, whereas application too infrequently invites photodamage. It may be prudent to follow the same approach of our Canadian colleagues of discontinuing combination products until more investigations are available.

Incidence of nonmelanoma skin cancer in a cohort of patients with vitiligo

BACKGROUND Nonmelanoma skin cancer (NMSC) incidence in patients with vitiligo has not been studied. OBJECTIVE We sought to quantify the incidence of NMSC in patients with vitiligo. METHODS A cohort of 477 patients with vitiligo and no history of NMSC seen in an outpatient academic center between January 2001 and December 2006 was established. All charts for patients with vitiligo were reviewed for incident NMSC, and histopathology verified. Age-adjusted (2000 US Standard Million) incidence rates were calculated and compared to US rates. RESULTS Six patients with NMSC were identified; all were Caucasian (>61 years). Age-adjusted incidence rates were: basal cell carcinoma, male 1382/100,000; basal cell carcinoma, female 0; squamous cell carcinoma, male 465/100,000; squamous cell carcinoma, female 156/100,000. Except for basal cell carcinoma in females, all rates were higher than US rates but not statistically significant. LIMITATIONS Comparison incidence rates from the general patient population during the same time period were unavailable. CONCLUSION Health care providers should be aware of the possible risk of NMSC in Caucasian patients with vitiligo.

Fields of Effects of 2 Commercial Preparations of Botulinum Toxin Type A at Equal Labeled Unit Doses: A Double-blind Randomized Trial

IMPORTANCE This article provides new data on a controversial issue, the influence of doses on the diffusion characteristics of 2 botulinum toxins type A. OBJECTIVE To assess the fields of effect of abobotulinumtoxinA and onabotulinumtoxinA at the same labeled unit dose (1:1 U) comparing sweat gland and muscle activity. DESIGN, SETTING, AND PARTICIPANTS A prospective, single-center, randomized, double-blind study was conducted at the Brazilian Center for Studies in Dermatology in Porto Alegre, Brazil. The participants included 19 women. INTERVENTIONS Each patient received 2 U of abobotulinumtoxinA on one side of the forehead and 2 U of onabotulinumtoxinA on the other side. MAIN OUTCOMES AND MEASURES Horizontal and vertical diameter and area of the fields of anhidrotic effect, the amplitude of evoked compound muscle action potentials, and the 4-point validated Wrinkle Severity Scale were assessed at 28 days. RESULTS The horizontal and vertical diameters of the fields of effect and the areas were significantly larger for onabotulinumtoxinA than those obtained for abobotulinumtoxinA. There were no significant differences between the products in the Wrinkle Severity Scale scores and Evoked Compound Muscle Action Potentials. OnabotulinumtoxinA had significantly more diffusion than abobotulinumtoxinA when isovolumetric injections of the same labeled unit dose of the products were injected. CONCLUSIONS AND RELEVANCE Although many studies state that diffusion is product dependent and abobotulinumtoxinA diffuses more than onabotulinumtoxinA, findings from the present study confirm that diffusion is dose dependent and the more potent dose tested diffuses more. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01732809.

Botulinum toxin type A for aging face and aesthetic uses

Botulinum neurotoxin type A injection to correct and/or reverse the physical effects of aging process has become one of the most frequently requested cosmetic procedures at an outpatient setting. Careful clinical evaluation together with proper use of the techniques, including pre‐ and post‐procedures recommendations, reconstitution of the products, techniques, and doses, are described in this article. This article also covers the main indications of botulinum neurotoxin type A for aging face and other aesthetic uses, as well as some possible adverse reactions and their management.

Quality of life assessment and disease experience of patient members of a web‐based hydroa vacciniforme support group

Background/Purpose: Hydroa vacciniforme (HV) is a rare photodermatosis that primarily affects children. It is characterized by photodistributed vesicles that heal with scarring. The purposes of this study are to perform the initial investigation into the effect of HV on quality of life (QoL) and gain insight into disease diagnosis and management.

Photoadaptation of vitiliginous skin to targeted ultraviolet B phototherapy.

Background: Increasing doses of ultraviolet (UV) radiation are tolerated in patients with vitiligo, due to photoadaptation. In this pilot study, five patients with Fitzpatrick skin phototypes IV–VI with vitiligo received six treatments of targeted UVB phototherapy over a 3‐week period.