Determination of Sensitive Skin in a Mexican Population by Lactic Acid Testing and Its Analysis Through Biophysical Measures
试验速览
- 阶段
- 4 期
- 状态
- 已完成
- 入组人数
- 260
- 试验地点
- 2
- 主要终点
- Sensitivity to lactic acid
研究概览
简要总结
Sensitive skin syndrome is a frequent self-diagnosed entity that has not been previously described in a Latin-american population. One hypothesis to its development is an alteration of the barrier function of the skin. The aim of the study is to describe the frequency of sensitive skin in a mexican population detected through the lactic acid test, and to explore its response through biophysical measures (colorimetry, transepidermal water loss (TEWL) and capacitance). The prevalence of this syndrome in studied populations is approximately 50%. Considering racial skin differences, the investigators would expect at least a 20% prevalence.
For this purpose, the investigators would need a minimum of 243 healthy volunteers, 18 years or older, with previous informed consent, to whom the lactic acid test will be performed. The investigators will record any unpleasant sensation graded in a Visual Analog Scale (VAS) of 10 points, colorimetry, TEWL and capacitance before the test and at 3, 5, 8 and 10 minutes after the lactic acid test.
详细描述
Sensitive skin is defined as the presence of itching, stinging, burning or other unpleasant sensations due to external factors (such as light, heat, cold, air, cosmetic products, soap, water and even emotional and hormonal factors). By definition it is a subjective syndrome, where there are no clinical signs, making it a self-diagnosed entity. Previous community-based studies, mostly in caucasians, have found a high prevalence in general population. Nonetheless, to date there are only a few studies and with a small amount of subjects that have applied an objective test to identify this syndrome, and even fewer have explored the possible alterations associated to it.
The investigators aim to describe the frequency in a hispanic population, and further explore the presence of alterations in the barrier function through measurement of TEWL and capacitance, as well as possible subclinical erythema (a* axis of colorimetry) or variations due to skin pigmentation (L* axis).
The volunteers in the study will be randomized to receive in one nasolabial fold 10% lactic acid solution, and placebo (0.9% saline solution) in the other to act as the control. The investigators will be grading any unpleasant sensation in a 10-point scale (VAS) at 4 different time intervals: 3, 5, 8 and 10 minutes. The investigators will be measuring colorimetry (ChromaMeter CR-300 (Minolta, Japan)), TEWL (Evaporimeter DermaLab (Cortex Technology, Denmark)) and capacitance (Corneometer DermaLab Moisture Module (Cortex Technology, Denmark)) before performing the test, and at 3, 5, 8 and 10 minutes after it. These time intervals have been previously determined according to previous reports where the maximum intensity of the response is obtained in the first 5 minutes, and after 10 minutes the response gradually diminishes.
Statistical analysis will be performed with square chi test, t-test or U-Mann-Whitney, according to the parametric or non-parametric distribution of the values. All tests will be performed using the JMP software 8.0 (Cary, NC, USA) at 95% of confidence, statistical significance at 5% with 80% power.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Diagnostic
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 70 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Healthy volunteers
- •Informed consent
排除标准
- •Pregnancy
- •Known allergy to lactic acid
- •Presence of any dermatoses in the nasolabial folds
- •Topical o systemic drugs in the previous 4 weeks
研究组 & 干预措施
Test subject
To each subject, the investigators will randomly apply 10% lactic acid on one nasolabial fold, once.
干预措施: 10% lactic acid test (Procedure)
Placebo
To each subject, the investigators will apply placebo (0.9% saline solution) on the contralateral nasolabial fold to the lactic acid, simultaneously.
干预措施: Placebo (Procedure)
结局指标
主要结局
Sensitivity to lactic acid
时间窗: 10 minutes
Identify and measure the presence of any unpleasant sensation after the application of 10% lactic acid test to the nasolabial fold. Will serve to identify subjects with sensitive skin.
次要结局
- Skin pigmentation(0 minutes)
- Erythema(0, 3, 5, 8 and 10 minutes)
- Transepidermal water loss(0, 3, 5, 8 and 10 minutes)
- Capacitance(0, 3, 5, 8, 10 minutes)
研究者
Juan Pablo Castanedo Cazares
Dermatology Research Director
Universidad Autonoma de San Luis Potosí