Sang Woong Youn

Influence of age and regional differences on skin elasticity as measured by the Cutometer

Background/aim: Aging of skin is accompanied by decrease of skin elasticity. Using the noninvasive suction device Cutometer®, we evaluated the age and regional body differences of the viscoelastic properties of human skin. The objectives of this study were to evaluate the correlation between age and the biomechanical parameters and the regional skin variations.

Regional and seasonal variations in facial sebum secretions: a proposal for the definition of combination skin type

Background/aims: Facial sebum secretions are known to change under various circumstances. Facial skin types have been categorized as oily, normal, dry, and combination types. However, these have been evaluated subjectively by individuals to date, and no objective accepted standard measurement method exists. The combination skin type is most common, but its definition is vaguer than the definitions of the other skin types.

Rapid healing and reduced erythema after ablative fractional carbon dioxide laser resurfacing combined with the application of autologous platelet-rich plasma.

BACKGROUND Fractional carbon dioxide laser resurfacing (FxCR) has shown considerable efficacy in reducing wrinkles, although complications such as scarring and prolonged erythema are more common and down‐time is longer than with nonablative laser treatment. Platelet‐rich plasma (PRP), a high concentration of platelets in a small volume of plasma, is known to enhance tissue healing. OBJECTIVE To evaluate the benefits of PRP in the wound healing process after FxCR. MATERIALS AND METHODS Twenty‐five subjects were treated with FxCR on the bilateral inner arms. PRP was prepared from 10 mL of whole blood and applied on a randomly allocated side, with normal saline being used as the contralateral control. Transepidermal water loss (TEWL) and skin color were measured on both sides. Skin biopsies were also taken from five subjects on day 28. RESULTS Significantly faster recovery of TEWL was seen on the PRP‐treated side. The erythema index and melanin index on the PRP‐treated side were lower than on the control side. Biopsy specimens from the PRP‐treated side showed thicker collagen bundles than those from the control side. CONCLUSION Application of autologous PRP is an effective method for enhancing wound healing and reducing transient adverse effects after FxCR treatment. The authors have indicated no significant interest with commercial supporters.

(-)-Epigallocatechin-3-gallate and hinokitiol reduce melanin synthesis via decreased MITF production

In this study, the effects of (−)-epigallocatechin-3-gallate (EGCG) and/or hinokitiol (β-thujaplicin) on melanogenesis were investigated. Our results showed that both EGCG and hinokitiol significantly inhibited melanin synthesis in a concentration-dependent manner, and that their hypopigmenting effects were stronger than that of kojic acid, which is known to inhibit melanin formation in melanocytes and melanoma cells. Interestingly, EGCG did not show any additive hypopigmenting effect in combination with kojic acid, though EGCG did show a synergistic effect in combination with hinokitiol. Several reports indicate that the activation of extracellular signal-regulated kinase (ERK) induces microphthalmia-associated transcription factor (MITF) degradation. Accordingly, the effects of EGCG and hinokitiol on the ERK signaling pathway were examined. EGCG and hinokitiol induced neither ERK activation nor MITF degradation. On the other hand, both EGCG and hinokitiol reduced the protein levels of MITF and of tyrosinase, the rate limiting melanogenic enzyme, whereas kojic acid had no effect. In addition, hinokitiol strongly downregulated the activity of tyrosinase, whereas EGCG or kojic acid had only a little effect. These results show that both EGCG and hinokitiol reduce MITF production, and suggest that reduced tyrosinase activity by hinokitiol explains their synergistic effect on melanogenesis.

Does facial sebum excretion really affect the development of acne

Background  It is generally accepted that the severity of acne is correlated with facial sebum secretion. However, previous studies on the relation between seborrhoea and the development of acne did not consider topographical differences in facial sebum secretion and used relatively vague acne severity grading systems.

The influences of skin visco-elasticity, hydration level and aging on the formation of wrinkles: a comprehensive and objective approach.

Various skin parameters including skin visco‐elasticity and hydration level affect the formation of wrinkles.

Evaluation of facial skin type by sebum secretion: discrepancies between subjective descriptions and sebum secretion.

Background/aims: Facial skin is usually classified as dry, normal, and oily in the cosmetics field. However, there is no standard objective method for classifying facial skin.

The role of facial sebum secretion in acne pathogenesis: facts and controversies

Increased sebum secretion has been known as one of the major pathogenic factors in the development of acne; however, objective sebum measurement methods have been developed only recently. We have limited information about the association of sebum secretion, and the development of acne. There continues to be controversy about the role of sebum in the development of acne. This contribution will discuss sebum measurement techniques and the results of recent studies on the relationship of sebum, facial cosmetic skin type, and acne. New therapeutic modalities for inflammatory acne aim to control seborrhea. Superficial chemical peels, laser treatment for inflammatory acne, and photodynamic therapy are used as adjunctive therapies for acne; however, their sebosuppressive effects are only temporary.

5 mg/day finasteride treatment for normoandrogenic Asian women with female pattern hair loss.

Background  Various treatments have been attempted for female pattern hair loss (FPHL), including topical minoxidil, oral antiandrogen and finasteride. But, there is no consensus on the standard treatment options. Clinical efficacy of finasteride in treating FPHL is still in controversy, but there is a tendency to high dose finasteride, which is more effective than lower dose.

Low-dose 1064-nm Q-switched Nd:YAG laser for the treatment of melasma

Abstract Background: Melasma is a common acquired pigmentary disorder which is sometimes hard to treat with conventional methods. Various kinds of modalities have been applied for the treatment of melasma but none shows constantly good results. Objectives: In this study, we would like to know the effect of low-dose 1064-nm Q-switched Nd:YAG laser (QSNYL) on melasma and want to evaluate the changes of skin after laser treatment. Methods: Twenty melasma patients were enrolled. Two regions were evaluated from each patient; a total of 40 sites. The 1064-nm QSNYL at fluences of 2.0–3.5 J/cm2 was used to treat the whole face, including the melasma lesions. The fluence was adjusted individually and increased until erythema was developed on the laser-treated area. The treatment was performed five times with a 1-week interval. Non-invasive measuring methods, including a chromatometer, mexameter, cutometer, visioscan and a corneometer, were used before and after treatment. Results: The L-value from the chromatometer, which reflects the lightness of skin, was increased (0.86 ± 1.67, p < 0.05). The melanin index from the mexameter was significantly decreased (–28.23 ± 28.21, p < 0.001). The SEw value from the visioscan, which reflects the degree of wrinkling, decreased (–5.80 ± 0.59, p = 0.040). None of the other measurement parameters showed significant changes. Conclusions: Low-dose 1064-nm QSNYL appears to be an effective treatment modality for melasma.