Bassel H. Mahmoud

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.

Treatment of Surgical Scars with Nonablative Fractional Laser Versus Pulsed Dye Laser: A Randomized Controlled Trial

OBJECTIVE Comparison of the efficacy of nonablative fractional laser (NAFL) and the V‐beam pulsed dye laser (PDL) for improvement of surgical scars. METHODS A randomized blinded split‐scar study. Fifteen scars in 12 patients were treated a minimum of 2 months after Mohs surgery. Patients were treated on half of the scar with a 1,550‐nm NAFL and on the contralateral half with the 595 nm PDL. MAIN OUTCOME MEASURE(S) A nontreating physician investigator evaluated the outcome of the scar in terms of scar dyspigmentation, thickness, texture, and overall cosmetic appearance (5‐point grading scale). RESULTS After a series of four treatments at 2‐week intervals, greater improvements were noted in the portion of surgical scars treated with NAFL (overall mean improvement 75.6%, range 60–100%, vs. PDL, 53.9%, range 20–80%; p<.001). CONCLUSION These data support the use of NAFL as a highly effective treatment modality for surgical scars, with greater improvement in scar appearance than with PDL. It is likely that the greater depth of penetration and focal microthermal zones of injury with NAFL, inducing neocollagenesis and collagenolysis, account for its greater improvement in scar remodeling. These encouraging results lead us to recommend that NAFL be added to the current treatment armamentarium for surgical scars. This project was supported by a grant from the Cosmetic Surgery Foundation.

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.

Safety and efficacy of erbium-doped yttrium aluminum garnet fractionated laser for treatment of acne scars in type IV to VI skin.

BACKGROUND Ablative resurfacing lasers are effective for treatment of acne scars, but they have a high risk of complications. Fractional lasers have less severe side effects but more moderate efficacy than ablative devices. Studies were performed in individuals with Fitzpatrick skin type I to VI. OBJECTIVE To determine the efficacy and safety of an erbium 1,550‐nm fractional laser in the treatment of facial acne scars in Fitzpatrick skin types IV to VI. METHODS We conducted a prospective, single‐blind, randomized trial in patients with acne scars (n=15), skin type IV to VI, with a 1,550‐nm erbium fractionated laser. Patients were divided into two groups; one was treated with 10 mJ and the other with 40 mJ. Five monthly laser sessions were performed. A patient questionnaire was distributed. RESULTS There was a significant improvement in the acne scarring and overall appearance (p<.001). No significant difference was found between 10 and 40 mJ. Patients were highly satisfied with their results. Significant postinflammatory hyperpigmentation was seen; pain was significantly higher in darker skin. CONCLUSIONS Fractional photothermolysis is effective for the treatment of acne scars, but practition‐ers should be aware of the higher incidence of pain and postinflammatory hyperpigmentation in individuals with skin types IV to VI. The study was funded by Reliant Technologies, Inc., which participated in the study design. Galderma (Ft. Worth, TX) provided Tri‐luma cream and GlaxoSmithKline (Research Triangle Park, NC) provided valacyclovir (Valtrex).

Paradoxical Hypertrichosis After Laser Therapy: A Review

BACKGROUND Laser hair removal is a safe and effective procedure for the treatment of unwanted body hair but is not exempt from side effects. A rare but significant adverse effect with this treatment modality is paradoxical hypertrichosis. OBJECTIVE To evaluate the potential etiologies, risk factors, related laser types, and treatment options for the development of excess hair after laser therapy. MATERIALS AND METHODS An analysis of previously published case studies and review articles along with our own experience was used to gather information regarding this phenomenon. RESULTS Paradoxical hypertrichosis has a low incidence, ranging from 0.6% to 10%, and most commonly occurs on the face and neck. All laser and light sources have the potential to cause hair induction, especially in individuals with darker skin types (III–VI); with dark, thick hair; and with underlying hormonal conditions. Possible causes include the effect of inflammatory mediators and subtherapeutic thermal injury causing induction of the hair cycle. Treatment for paradoxical hypertrichosis is laser therapy of the affected area. CONCLUSIONS Paradoxical hypertrichosis is a rare side effect of laser hair removal; the pathogenesis of this event remains widely unknown. We recommend further large‐scale studies to investigate this effect. The authors have indicated no significant interest with commercial supporters.

Systemic analyses of immunophenotypes of peripheral T cells in non-segmental vitiligo: implication of defective natural killer T cells.

Although it is widely believed that non‐segmental vitiligo (NSV) results from the autoimmune destruction of melanocytes, a clear understanding of defects in immune tolerance, which mediate this uncontrolled self‐reactivity, is still lacking. In the present study, we systemically evaluated circulating regulatory T (Treg) cells, including CD4+CD25+FoxP3+ Treg cells and invariant natural killer T (iNKT) cells, as well as naïve and memory CD4+ and CD8+ T cells and their cytokine production, in a cohort of 43 progressive NSV patients with race‐, gender‐, and age‐matched healthy controls. We found that the general immunophenotypes of CD4+ and CD8+ T cells and the percentage of CD4+CD25+FoxP3+ Tregs were comparable between NSV and healthy controls. However, percentages of peripheral iNKT cells were significantly decreased in NSV patients compared to that in healthy controls. Our data confirm the previous notion that the percentage of peripheral CD4+CD25+FoxP3+ Tregs remains unaltered in NSV and suggests the involvement of defective iNKT cells in the pathogenesis of NSV.

Histopathologic Study of Hidradenitis Suppurativa Following Long-Pulsed 1064-nm Nd:YAG Laser Treatment

OBJECTIVE To assess clinical and histopathologic changes occurring after long-pulsed 1064-nm Nd:YAG laser treatment of hidradenitis suppurativa (HS). DESIGN Prospective, controlled clinical and histologic study of patients with Hurley stage II HS disease. SETTING Outpatient dermatology department at Henry Ford Hospital, Detroit, Michigan. PARTICIPANTS Nineteen patients with Fitzpatrick skin types II to VI with Hurley stage II HS lesions of the axilla and groin. Interventions Two monthly laser sessions were performed using the long-pulsed 1064-nm Nd:YAG laser. Main Outcome Measure Clinical response was scored using the modified Sartorius scale for HS reflecting Lesion Area and Severity Index (LASI). Histologic changes were examined before treatment and 1 week, 1 month, and 2 months after treatment. RESULTS The percentage change in HS severity after 2 sessions of laser treatment was -31.6 over all anatomic sites (P < .005), -24.4 for the axillary site (P = .008), and -36.8 for the inguinal site (P = .001). Histologic changes corresponded to clinical response. Findings from serial biopsy specimens showed increased inflammation at 1 week after treatment and decreased inflammation with resulting fibrosis and scarring at 1 month and 2 months after treatment. CONCLUSIONS The long-pulsed 1064-nm Nd:YAG laser is a novel effective treatment option for HS. Our histopathologic data suggest that HS is primarily a follicular disorder. The Nd:YAG laser penetrates for selective photothermolysis of the follicular unit and destruction of organized inflammatory lesions in the superficial to mid dermis. Our study offers insight into the pathogenesis of HS and the mechanism of the Nd:YAG laser in treatment of patients with this chronic, debilitating disease.

Granuloma Annulare Treated With Rifampin, Ofloxacin, and Minocycline Combination Therapy

BACKGROUND Granuloma annulare (GA) is a benign, usually self-limiting, dermatosis, that typically presents as asymptomatic, flesh-colored or erythematous papules, frequently arranged in an annular or arciform pattern on the distal extremities. Although localized GA is most commonly observed, a generalized or disseminated form can occur. The etiology of GA is unknown; however, multiple inciting factors have been proposed. Histologically, GA is characterized by foci of degenerative collagen associated with palisading, sometimes infiltrating granulomatous inflammation. OBSERVATIONS We report 6 cases with biopsy-proved GA, resistant to the standard modalities of treatment that resolved after 3 months with monthly rifampin (600 mg), ofloxacin (400 mg), and minocycline hydrochloride (100 mg) combination therapy. Rifampin, ofloxacin, and minocycline combination therapy has been successfully used to treat patients with paucibacillary leprosy. Given reports that prolonged antibiotic agents are a useful treatment for GA, rifampin (600 mg), ofloxacin (400 mg), and minocycline hydrochloride (100 mg) combination therapy was initiated in these patients. Complete clearance of the plaques was achieved 3 to 5 months after the initiation of treatment. Some patients experienced postinflammatory hyperpigmentation. CONCLUSION Although our treatment was effective, further studies may be needed to confirm the success of this therapeutic option for patients with recalcitrant lesions of GA.

MicroRNA expression profiling identifies potential serum biomarkers for non-segmental vitiligo

To take out a personal subscription, please click here More information about Pigment Cell & Melanoma Research at www.pigment.org MicroRNA expression profiling identifies potential serum biomarkers for non-segmental vitiligo Yu-Ling Shi, Matthew Weiland, Jia Li, Iltefat Hamzavi, Marsha Henderson, Richard H. Huggins, Bassel H. Mahmoud, Oma Agbai, Xiaofan Mi, Zheng Dong, Henry W. Lim1,2, Qing-Sheng Mi and Li Zhou