Ultraviolet and UV-Visible Light Photoprotection for the Treatment of Melasma

A Double Blind Randomized Study Comparing the Ultraviolet (UV) Photoprotection With UV Plus Visible Light Photoprotection in the Treatment of Melasma.

Melasma is an acquired discoloration of the skin characterized by brown colour changes commonly on the face. The duration of this double-blind clinical trial will be 12 weeks. The control group will receive treatment with topical Hydroquinone (4%) and a Broad spectrum UV sunscreen. The experimental group, 4% topical hydroquinone and a Broad spectrum UV-visible light sunscreen. Visible light has melanotic properties and avoiding it can be part of the treatment for melasma patients. The estimated number of subjects to be recruited and randomized for the study is at least 25 per group. The purpose of this study is determine if there is a difference in the improvement between these two sunscreens types. Melasma Area and Severity Index (MASI) score will be assessed at the beginning of the study and at weeks 4, 8, and 12. Photographs, colorimetry and histological assessment will be also evaluated. Occurrence of adverse effects will also be recorded.

Melasma is a common acquired hypermelanosis in dark skin populations, usually characterized by symmetrical, irregular macules occurring in photo-exposed areas such as face. Treatment with sunscreens and depigmenting compounds such as hydroquinone, are still the gold standard in this condition. Visible light has pigmenting properties that could be interfering with the treatment in melasma patients. So, the primary objective of this study is to compare the depigmenting adjuvant effect of using a UV-visible blocking sunscreen against a UV sunscreen. Patients who are included in the study will be randomly assigned to receive one of the sunscreen type, which should use for 12 weeks. The sun blocking agents should be applied in the affected regions every 3 hours from 8AM to 5PM. The evaluation of clinical improvement will be done in a blinded modality by means of the MASI score, the Global Physician Assessment, as well as colorimetry and histological melanin content. Evaluations will be held on visits at 4, 8 and 12 weeks. Skin biopsy will be taken at onset and at 12 weeks. At the end of the study, data will be compared concerning the former parameters. All side effects will be recorded and analysed.

Sunscreen containing Mexoryl SX, Mexoryl XL, Titanium Dioxide, Octocrylene, Tinosorb S, Avobenzone, and Ethylhexyl triazone. Fluid vehicle administered daily, from 8AM to 5PM every 3 hr, for 12 weeks.

Sunscreen containing Benzophenone-3, Octinoxate, Octocrylene, Titanium Dioxide, Zinc Oxide, and iron oxide. Fluid vehicle administered daily, from 8AM to 5PM every 3 hr, for 12 weeks.

Octocrylene, Titanium dioxide, Butyl methoxydibenzoylmethane, Bis-ethylhexyloxyphenol methoxyphenyl triazine, Drometrizole trisiloxane, Ethylhexyl triazone, Terephthalylidene dicamphor sulfonic acid

A broad UV spectrum sunscreen will be applied every 3 hours for 12 weeks. The affected surface will be covered with a 2 mg/cm^2 layer of the product as indicated on the affected areas of the face.

A UV-visible light spectrum sunscreen will be applied every 3 hours for 12 weeks. The affected surface will be covered with a 2 mg/cm^2 layer of the product as indicated on the affected areas of the face.

Quantification of the colour change in the melasma lesions by means of the L axis of the CIE system. 0 value is pure white, 100 value is total black.

It is a clinical instrument of melasma measurement. The total score would range from 0-24, involving the forehead (30%), right malar (30%), left malar (30%) and chin (10%), and using area of involvement (0=absent, 1=<10%, 2=10%-29%, 3=30%-49%, 4=50%-69%, 5=70%-89% and 6=90%-100%) and darkness (0=absent, 1=slight, 2=mild, 3=marked and 4=severe). Computation would be as follows: 0.3 A(f) D(f) + 0.3 A(lm) D(lm) + 0.3 A(rm) D(rm) + 0.1 A(c) D(c).

The Fontana-Masson Stain is specific for melanin, this histochemical reaction reveals accumulations of black material wherever melanin is located. A skin biopsy of lesions will be taken initially and at the end of study. The melanin content will be quantified by a software image analysis of the slides.

Clinical improvement is assessed by means of digital photographic registration (frontal, right, and left views). An independent observer clinically graded the global improvement as poor (0-25%), mild (26-50%), good (51-75%), and excellent (>75%).

Inclusion Criteria: Signed informed consent Women over 25 years of age Dermatologic diagnostic of melasma Phototype III or more Exclusion Criteria: Pregnant or breastfeeding Postbirth, abortion in the past 6 months Having an endocrine or autoimmune disease Under hormonal therapy of any kind including contraceptives or it´s use in the past 6 months Currently under treatment for melasma including sunscreens Currently under radiation therapy, chemotherapy, immunosuppressants of any kind or phototherapy or it´s use in the past 6 months Having used or are consuming photosensitizing substances, oral or topical

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