الفهرس 
Melanocyte Biology and MelanogenesisOnly 14 pages are availabe for public view
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Abstract
Melasma is an acquired hypermelanosis on sun exposed areas of the body that occurs in all races but has a predilection for darker skin populations. It usually affects females during childbearing age, but can also be seen in men. Melasma can be divided clinically into centrofacial, malar and mandibular according to the pigment distribution and can be classified into epidermal, dermal and mixed type by Wood’s light. The pathogenesis of melasma is unknown however; genetic predisposition, hormonal influence, pregnancy and UV light exposure are considered as causative and exacerbating factors. Current treatments include sunscreens, hypopigmenting agents, chemical peels and lasers which can be used in the form of monotherapy or combined therapy and yet, melasma treatment remains a challenge for dermatologists.
Chemical peeling is effective in the treatment of melasma and TCA was also found to be the gold standard in the treatment of melasma, especially with the proper selection of the patient, proper priming and post-peel care. Laser treatments as Q-switched, ablative lasers and intense pulsed light have been used to treat melasma, but they were of limited efficacy and high risk of complications. Fractional photothermolosis (FP) has been introduced to overcome these limitations where ablative FP using the Er:YAG laser (2940nm) would be as effective as traditional ablative while avoiding their high downtime and risks.
Summary
129
In this study, we compared topical 15% TCA peeling (group T), to ablative fractional Er:YAG (2940) (group E) in the treatment of 20 (10 cases in each group) cases of melasma (epidermal type) for 3 sessions (every 3 weeks). They were all female patients. There was no priming for the patients, only sunscreen and emollients were used.
We evaluated the results by MASI score, photography, digital image analysis (using photoshop for calculating the area) together with patients’ self-evaluation before treatment, after treatment (4 weeks) and at the end of follow-up period (12 weeks).
At the end of the treatment, there was a significant decline in MASI score (17.21%), area (12.4%) and average darkness (11.8%) in Erbium group. While in TCA group, there was a 16.08%, 15.9% and 11.47% decline respectively.
Moreover at the end of follow up, there was a significant decline in MASI score (24.14%), area (9.11%) and average darkness (15.86%) in Erbium group. While in TCA group, there was a 29.26%, 17.4% and 16.3% decline respectively.
However, on comparing both groups together, at the end of the treatment and at the end of the follow up period, the results of group (T) and (E) were statistically non significant regarding MASI score, Area and Average darkness.
Summary
130
There was no significant difference between (E) and (T) cases as regards subjective evaluation, as 30% of erbium cases reported good to excellent improvement after treatment compared to 30% of TCA cases.
Side effects were mild and transient in both groups that did not stop the patients from continuing their sessions.
In conclusion: both 15% TCA and ablative fractional Er:YAG (2940nm) laser were found to be beneficial and gave comparably close results in treatment of epidermal melasma. Therefore, TCA 15% is recommended due to effectiveness and less cost.