Determination of an optimized conversion matrix for device independent skin color image analysis

The effects of the oral supplementation of L-Cystine associated with reduced L-Glutathione-GSH on human skin pigmentation: a randomized, double-blinded, benchmark- and placebo-controlled clinical trial

BACKGROUND

Glutathione has become a potential skin-lightening ingredient after the discovery of its anti-melanogenic properties. Various mechanisms of action have been considered to explain this property, one of them being the skewing of the melanin synthesis pathway toward the production of lighter pheomelanin instead of darker eumelanin, consequently producing a lightening effect.

AIMS

To evaluate the skin lightening and anti-dark spot effects of oral supplementation with L-Cystine associated with L-Glutathione as compared to placebo and benchmark.

METHODS

Effects of this L-Cystine-L-Glutathione oral combination were investigated in a 12-week randomized, double-blind, parallel-group, benchmark- and placebo-controlled trial involving 124 Asian female subjects. Women were randomly allocated into 4 equal groups (500 mg L-Cystine and 250 mg L-Glutathione, 250 mg reduced L-Glutathione, 500 mg L-Cystine, or a placebo, daily). Skin color was measured at baseline, after 6 and 12 weeks by spectrophotometry. Size and color of facial dark spots were determined from digital photographs.

RESULTS

A significant skin lightening was observed after 12 weeks of oral supplementation with L-Cystine associated with L-Glutathione. This combination also induced a significant reduction in the size of facial dark spots after 6 and 12 weeks. It is noteworthy that the observed effects were not only significantly better than those obtained with placebo, but also with L-Cystine alone or L-Glutathione alone.

CONCLUSION

The daily oral administration of 500 mg L-Cystine and 250 mg L-Glutathione during 12 weeks was a safe treatment to effectively lighten the skin and reduce the size of facial dark spots of Asian women.

Analysis of facial redness by comparing VISIA® from Canfield and CSKIN® from Yanyun Technology

BACKGROUND

Redness is the most common symptom among many facial dermatoses. With the rapid development of optical instruments, spectral imaging, and image processing technology, there appear varieties of skin color analysis methods and instruments. The aim of this study is to reveal the differences and correlations in measuring the facial redness between CSKIN^® and VISIA^® , as well as the relevance between the instrument parameters and clinical evaluation.

MATERIALS & METHODS

Forty-three Chinese patients were enrolled. Images were taken and analyzed by VISIA^® from Canfield and CSKIN^® from Yanyun Technology, and the facial erythema was graded by the dermatologists.

RESULTS

Feature counts within the red areas measured by VISIA^® were found to have significantly positive correlations with red pixels and percent which were measured by CSKIN^® on both sides of the face (r = .45 ~ .566, P < .01). The parameters analyzed by CSKIN^® and VISIA^® feature counts were correlated with visual scores graded by the dermatologists, VISIA^® presented with a weak correlation (r = .213, P < .05), while CSKIN^® had a moderate correlation with the visual scores (r = .472 ~ .492, P < .001).

CONCLUSION

CSKIN^® may be another alternative option when encountering with measurement and follow-up of facial erythema.

Daily Variation of UV-induced Erythema and the Action of Solar Filters

UV rays may cause several degrees of skin damage, which makes sunscreen research necessary. In addition, skin sensitivity shows daily variations, which can interfere in the detection of the efficacy of the filters. Here, we studied the UV-induced erythema in hairless rats at two times of the day (light and darkness) using a colorimeter method. The effect of an emulsion with solar filters with or without melatonin was also assayed. Results indicate that the value of a* (from CIELAB color space values L* a* b) was the most useful variable to evaluate the erythema. However, at the UV intensity used, erythema was only detected when irradiation was carried out during the activity phase of the animal, enabling the detection of the protective action of the sunscreen at this time. Thus, daily variations in skin sensitivity have been demonstrated and should be taken into account in dermatological research.

Why do port-wine stains (PWS) on the lateral face respond better to pulsed dye laser (PDL) than those located on the central face?

BACKGROUND

After pulsed dye laser (PDL) treatment, facial lateral port-wine stains (PWS) clear quicker and more completely than central PWS do.

OBJECTIVE

We sought to investigate whether the difference in the efficacy of the treatment between central and lateral facial PWS was related to different histologic manifestations.

METHOD

Thirteen patients with PWS had biopsies and underwent PDL treatments in both central and lateral areas of the face. The hypothesis was tested by correlating the PWS response to PDL with the depth and diameter of the PWS vessels. The clinical efficacy was assessed by chromameter 2 months after the final PDL treatment, whereas diameter and depth of PWS vessels were measured in biopsy specimens.

RESULTS

All patients were treated on central and lateral facial sites. The chromameter evaluation showed that the average blanching rate was 34.01% and 8.68% for lateral and central facial sites, respectively (P < .05), which suggests a better response to PDL treatment in the lateral than in the central area. Histologic manifestations showed that vessels in the lateral regions were primarily located in the papillary dermis, whereas in the central regions they were extensively distributed from the dermis into the subcutaneous tissue.

LIMITATIONS

The small number of cases included in this study and the lack of follow-up longer than 2 months constitute limitations.

CONCLUSION

Lateral facial PWS respond better to PDL than PWS located in the central face. Differences in vessel location and diameter may be responsible for the variations in PWS response to PDL.

Noninvasive clinical assessment of port-wine stain birthmarks using current and future optical imaging technology: a review

Port-wine stain (PWS) birthmarks are one class of benign congenital vascular malformation. Laser therapy is the most successful treatment modality of PWS. Unfortunately, this approach has limited efficacy, with only 10% of patients experiencing complete blanching of the PWS. To address this problem, several research groups have developed technologies and methods designed to study treatment outcome and improve treatment efficacy. This article reviews seven optical imaging techniques currently in use or under development to assess treatment efficacy, focusing on: reflectance spectrophotometers/tristimulus colorimeters; laser Doppler flowmetry and laser Doppler imaging; cross-polarized diffuse reflectance colour imaging system; reflectance confocal microscopy; optical coherence tomography; spatial frequency domain imaging; and laser speckle imaging.

Enhanced port-wine stain lightening achieved with combined treatment of selective photothermolysis and imiquimod

BACKGROUND

Pulsed dye laser (PDL) is the gold standard for treatment of port-wine stain (PWS) birthmarks but multiple treatments are required and complete resolution is often not achieved. Posttreatment vessel recurrence is thought to be a factor that limits efficacy of PDL treatment of PWS. Imiquimod 5% cream is an immunomodulator with antiangiogenic effects.

OBJECTIVE

We sought to determine if application of imiquimod 5% cream after PDL improves treatment outcome.

METHODS

Healthy individuals with PWS (n = 24) were treated with PDL and then randomized to apply posttreatment placebo or imiquimod 5% cream for 8 weeks. Chromameter measurements (Commission Internationale de l'Eclairage L∗a∗b∗ colorspace) for 57 PWS sites (multiple sites per patient) were taken at baseline and compared with measurements taken 8 weeks posttreatment. The Δa∗ (change in erythema) and ΔE (difference in color between normal-appearing skin and PWS skin) were measured to quantify treatment outcome.

RESULTS

Two patients developed minor skin irritation. Other adverse effects were not noted. Average ∆a∗ was 0.43 for PDL + placebo sites (n = 25) and 1.27 for PDL + imiquimod sites (n = 32) (P value = .0294) indicating a greater reduction in erythema with imiquimod. Average ∆E was 2.59 for PDL + placebo and 4.08 for PDL + imiquimod (P value = .0363), again indicating a greater color improvement with imiquimod.

LIMITATIONS

Effects were evaluated after a single treatment and duration of effect is unknown.

CONCLUSION

Combined selective photothermolysis and antiangiogenic therapy may enhance PWS treatment efficacy.