Determination of Sensitive Skin and Its Biophysical Response in a Latin-American Population

NCT ID: NCT01591993

Last Updated: 2012-11-29

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE4
• Total Enrollment: 260 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2011-10-31
• Study Completion Date: 2012-08-31

Brief Summary

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.

Detailed Description

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.

Conditions

Skin Irritancy Tests

Keywords

Sensitive skin; Lactic acid test; Transepidermal water loss; Colorimetry; Capacitance

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: DIAGNOSTIC
• Blinding Strategy: TRIPLE

Study Groups

Test subject

To each subject, the investigators will randomly apply 10% lactic acid on one nasolabial fold, once.

Group Type: EXPERIMENTAL

10% lactic acid test

Intervention Type: PROCEDURE

To each subject, 10% lactic acid is applied to one nasolabial fold. This will be performed under humidity, temperature and pH control to avoid influence of these variables in the result of the test.

Placebo

To each subject, the investigators will apply placebo (0.9% saline solution) on the contralateral nasolabial fold to the lactic acid, simultaneously.

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: PROCEDURE

To each subject, 0.9% saline solution will be applied to the contralateral nasolabial fold. This will be performed under humidity, temperature and pH control to avoid influence of these variables in the result of the test.

Interventions

10% lactic acid test

To each subject, 10% lactic acid is applied to one nasolabial fold. This will be performed under humidity, temperature and pH control to avoid influence of these variables in the result of the test.

Intervention Type: PROCEDURE

Placebo

To each subject, 0.9% saline solution will be applied to the contralateral nasolabial fold. This will be performed under humidity, temperature and pH control to avoid influence of these variables in the result of the test.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

• Healthy volunteers
• Informed consent

Exclusion Criteria

• Pregnancy
• Known allergy to lactic acid
• Presence of any dermatoses in the nasolabial folds
• Topical o systemic drugs in the previous 4 weeks

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Hospital Central "Dr. Ignacio Morones Prieto"

OTHER

Sponsor Role: collaborator

Universidad Autonoma de San Luis Potosí

OTHER

Sponsor Role: lead

Responsible Party

Juan Pablo Castanedo Cazares

Dermatology Research Director

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Diana V Hernández-Blanco, MD

Role: PRINCIPAL_INVESTIGATOR

Dermatology Department. Hospital Central "Dr. Ignacio Morones Prieto"

Adriana Ehnis-Pérez, MD

Role: PRINCIPAL_INVESTIGATOR

Dermatology Department. Hospital Central "Dr. Ignacio Morones Prieto"

Juan P Castanedo-Cázares, MD

Role: STUDY_DIRECTOR

Dermatology Department. Hospital Central "Dr. Ignacio Morones Prieto"

Bertha Torres-Álvarez, MD

Role: STUDY_CHAIR

Dermatology Department. Hospital Central "Dr. Ignacio Morones Prieto"

Locations

Dermatology Department. Hospital Central "Dr. Ignacio Morones Prieto"

San Luis Potosí City, San Luis Potosí, Mexico

Countries

Mexico

References

Seidenari S, Francomano M, Mantovani L. Baseline biophysical parameters in subjects with sensitive skin. Contact Dermatitis. 1998 Jun;38(6):311-5. doi: 10.1111/j.1600-0536.1998.tb05764.x.

Reference Type: BACKGROUND

PMID: 9687028 (View on PubMed)

Issachar N, Gall Y, Borell MT, Poelman MC. pH measurements during lactic acid stinging test in normal and sensitive skin. Contact Dermatitis. 1997 Mar;36(3):152-5. doi: 10.1111/j.1600-0536.1997.tb00399.x.

Reference Type: BACKGROUND

PMID: 9145266 (View on PubMed)

Sparavigna A, Di Pietro A, Setaro M. 'Healthy skin': significance and results of an Italian study on healthy population with particular regard to 'sensitive' skin. Int J Cosmet Sci. 2005 Dec;27(6):327-31. doi: 10.1111/j.1467-2494.2005.00287.x.

Reference Type: BACKGROUND

PMID: 18492170 (View on PubMed)

Other Identifiers

SenSk12

Identifier Type: -

Identifier Source: org_study_id