Acne erythema improvement by long-pulsed 595-nm pulsed-dye laser treatment: a pilot study.

OBJECTIVES: Recent studies have demonstrated that pulsed-dye laser (PDL) treatment is beneficial for inflammatory acne treatment. However, persistent erythema after inflammatory acne vulgaris ('acne erythema') remains a therapeutic challenge. The objectives of this study were to evaluate the clinical efficacy and safety of a long pulse duration 595-nm PDL (V-beam laser) therapy for the treatment of acne erythema. METHODS: Twenty patients with acne erythema were treated using two successive sessions with a 595-nm PDL at 4-week intervals. Overall acne severities were assessed using Leeds scores, degree of improvement using standardized digital photographs, erythema indexes and skin elasticity findings at baseline, and 4 weeks after each treatment. Patients' self-assessments were also recorded. RESULTS: A total of 90% of acne erythema patients achieved clinical improvement. Lesion counts decreased 24.9% after the first treatment (p<0.05) and by 57.6% (versus baseline) after the second treatment (p<0.05). Significant improvements were also noted in mean Leeds scores, erythema indexes, and skin elasticities after each treatment. Treatment-related pain was well-tolerated and adverse effects were limited to transient erythema and edema at treatment sites. CONCLUSION: A long pulse duration 595-nm PDL was found to improve acne erythema with minimal discomfort and an increase in skin elasticity.

Photo-epilation results of axillary hair in dark-skinned patients by intense pulsed light: comparison between different wavelengths and pulse width.

BACKGROUND: Recently, intense pulsed light (IPL) sources have been shown to provide long-term hair removal. OBJECTIVE: This study examined the photo-epilatory effects of different wavelengths and pulse width application in the same IPL device and compared their efficiencies in Asian skin. METHODS: Twenty-eight Korean women were treated using hair removal (HR) (600-950 nm filter) and 27 using HR-D (645-950 nm filter) in the axillary area. Four treatments were carried out at intervals of 4 to 6 weeks; follow-ups were conducted 8 months after the last treatment. Mean energy settings were 14.9 6 2.0 J/cm2 for HR and 17.1 6 0.6 J/cm2 for HR-D. Longer pulse widths were applied in case of HR-D treatment. Hair counts and photographic evaluation of skin sites were made at baseline and at the last follow-up. Final overall evaluations were performed by patients and clinicians. RESULTS: Average clearances of 52.8% and 83.4% were achieved by HR and HR-D, respectively. No significant adverse effects were reported after HR-D treatment. One case each of hypopigmentation and hyperpigmentation was reported for HR. CONCLUSION: An IPL source removing 45 nm of the emitted spectra and applying a longer pulse width was found to provide a safer and more effective means of photo-epilation in Asian patients.

Cellular senescence induced loss of stem cell proportion in the skin in vitro.

BACKGROUND: It is known that cellular senescence could affect culture results. A previous study on K19 found that the loss of stem cell proportion is the reason for difficulties experienced when culturing aged keratinocytes. But the situation is unclear, because K19 is not generally accepted as an epidermal stem cell marker. OBJECTIVE: The aim of this study was to investigate the effects of cellular senescence caused by chronological aging or by repeated subcultures. METHODS: The effects of cellular senescence were investigated using monolayer cultures of keratinocytes and reconstructed epidermis. We prepared keratinocytes from donors of different ages and by repeated subcultures. Flow cytometric analysis was performed using alpha6 integrin and CD71 antibodies, and candidate keratinocyte stem cell proportions were separated according to reactivities to these antibodies. Living skin equivalents (LSEs) were reconstructed using keratinocytes from child, adult and elderly donors. RESULTS: Flow cytometric analysis showed a decrease in the candidate stem cell proportion in an age- or culture passage-dependent manner. LSE experiments showed that a reconstructed epidermis using child's keratinocytes was well formed compared to epidermis reconstructed using an elderly donor's keratinocytes. Different expression of proliferation markers was also observed according to donor age. CONCLUSION: Our results showed that cellular senescence by chronological aging or repeated sub-culture induced the loss of candidate stem cell proportion in keratinocyte cultures. This seems to be the reason why it is difficult to culture keratinocytes from the elderly or by repeatedly culturing keratinocytes in vitro.