***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Abstract Background : Tranexamic acid ( TNA ) is a novel therapeutic agent for hyperpigmented skin disorders . The efficacy and safety of topical TNA in patients with melasma  has not been heretofore studied . The main objective of this study is to evaluate the efficacy and safety of topical TNA combined with intense pulsed light ( IPL ) treatment in Asians with melasma . Methods : A r and omized , split-face ( internally controlled ) study was conducted in 15 women who received four monthly sessions of IPL to both sides of the face .  Topical TNA or vehicle was applied to a r and omly assigned side during and after IPL treatment . Patients were followed up for 12 weeks after completing the IPL treatments . Baseline and follow-up melanin index ( MI ; measured by Mexameter ® , Courage and Khazaka , Cologne , Germany ) and modified melasma area and severity index ( mMASI ) scores were determined . Results : Thirteen subjects completed the study  without serious adverse events . MI and mMASI decreased significantly from baseline to 12 weeks after the last IPL treatment on the topical TNA side but not on the vehicle side . The efficacy of topical TNA in preventing rebound pigmentation after IPL treatment was also statistically significant . Conclusion : Topical TNA can be considered an effective and safe adjuvant to conventional treatment for melasma BACKGROUND AND DESIGN Melasma is an acquired , masklike , facial hyperpigmentation . The pathogenesis and treatment of melasma in black ( African-American ) patients is poorly understood . We investigated the efficacy of topical 0.1 % all-trans-retinoic acid ( tretinoin ) in the treatment of  melasma in black patients . Twenty-eight of 30 black patients with melasma completed a 10-month , r and omized , vehicle-controlled clinical trial in which they applied either 0.1 % tretinoin or vehicle cream daily to the entire face . They were evaluated clinical ly ( using our Melasma Area and Severity Index ) , colorimetrically , and histologically . RESULTS After 40 weeks , there was a 32 % improvement in the Melasma Area and Severity Index score in the tretinoin treatment group compared with a 10 % improvement in the vehicle group . Colorimetric measurements showed lightening of melasma after 40 weeks of tretinoin treatment vs vehicle . Lightening of melasma , as determined clinical ly , correlated well with colorimetric measurements . Histologic examination of involved skin revealed a significant decrease in epidermal pigmentation in the tretinoin group compared with the vehicle group . Side effects were limited to a mild " retinoid dermatitis " occurring in 67 % of tretinoin-treated patients . Among the patients in this study in comparison with comparably recruited white patients , melasma was reported to have begun at a later age and was more likely to be in a malar distribution . CONCLUSIONS This controlled study demonstrates that topical 0.1 % tretinoin lightens melasma in black patients , with only mild side effects Abstract Background : Topical tranexamic acid has been cl aim ed to lighten melasma without serious adverse effects . However , controlled studies assessing the efficacy and safety of topical tranexamic acid ( TA ) for the treatment of melasma is limited . Objective : To assess in a double blind , r and omized , prospect i ve study , the efficacy of topical 5 % tranexamic acid versus vehicle for treatment of melasma . Methods : Twenty-three women with bilateral epidermal melasma enrolled in a split-face trial lasting 12 weeks . Patients blindly applied topical 5 % tranexamic acid and its vehicle , to the design ated sides of the face twice daily in addition to the assigned sunscreen each morning . Pigmentation and erythema were measured objective ly using a mexameter and Melasma Area and Severity Index ( MASI ) , in addition to physician and patient global assessment s. Results : Twenty-one patients completed the study . Eighteen out of twenty-three patients ( 78.2 % ) showed decrease in the melanin index on either or both sides of the face by the end of 12 weeks compared to baseline . The MASI scores were also significantly reduced on both tested sides . However , lightening of pigmentation induced by TA gel was neither superior nor different ( p > 0.05 ) compared to its vehicle although erythema was significant on the TA-applied site ( p < 0.05 ) . Conclusions : Although lightening of pigmentation was obtained , the results were not significant between the two regimens . However , topical TA produced erythema BACKGROUND Melasma is a common cosmetic problem among Asians . While various treatments are currently being used , there is no entirely satisfactory treatment . It was recently reported that the topical plasmin inhibitor is an effective treatment for ultraviolet-induced hyperpigmentation . OBJECTIVE Because there are no studies assessing the efficacy and safety of localized microinjection of tranexamic acid ( TA ) for the treatment of melasma , we conducted a pilot study to evaluate the efficacy and side effects of this potentially new method for the treatment of melasma in Korean women . METHODS A total of 100 women with melasma , after written consent , were enrolled for a prospect i ve open pilot study of 12 weeks . After applying topical anesthesia , 0.05 mL TA ( 4 mg/mL ) was injected intradermally into the melasma lesion at 1 cm intervals by using a 0.5 mL insulin syringe with a 30-gauge needle . This was repeated weekly for 12 weeks . A clinical investigator evaluated the results by using the Melasma Area and Severity Index ( MASI ) at baseline and at 4 , 8 , and 12 weeks . The patient satisfaction question naire was documented at 12 weeks . Safety evaluations were performed at each follow-up visit . RESULTS Eighty-five patients completed the trial . A significant decrease in the MASI from baseline to 8 and 12 weeks was observed ( 13.22±3.02 vs 9.02±2.62 at week 8 and vs. 7.57±2.54 at week 12 ; p<.05 for both ) . The patients ' self- assessment of melasma improvement was as follows : 8 of 85 patients ( 9.4 % ) rated as good ( 51–75 % lightening ) , 65 patients ( 76.5 % ) as fair ( 26–50 % lightening ) , and 12 patients ( 14.1 % ) as poor ( 0–25 % lightening ) . Side effects were minimal and all the patients tolerated the treatment well . CONCLUSION Based on these results , we suggest that the intralesional localized microinjection of TA acid can be used as a potentially new , effective , and safe therapeutic modality for the treatment of melasma BACKGROUND Melasma is associated with epidermal hyperpigmentation , weak basement membrane , vascular proliferation and increased numbers of mast cell . Tranexamic acid ( TXA ) , a plasmin inhibitor , is reported to improve melasma when injected locally . However , the effects of oral and topical TXA on melasma have not been well studied and the underlying mechanism remains unclear . OBJECTIVES To eluci date the effects of oral and topical TXA on melasma . METHODS A clinical study was conducted with 25 women for 8 weeks from March to July 2010 . Volunteers were instructed to take two TXA tablets three times a day and apply a TXA topical agent twice a day for 8 weeks .  Skin pigmentation and erythema was measured using a Mexameter ( ® ) during each visit and skin biopsies were collected from eight subjects before and 8 weeks after treatment . Fontana-Masson , anti-CD31 , antitryptase and antitype IV collagen staining was performed . RESULTS Twenty-two subjects completed the study and no serious adverse events occurred during the study period . The mean lesional melanin index ( MI ) scores decreased significantly . Interestingly , the MI scores for the perilesional skin increased . The erythema index scores of lesional and perilesional skin also showed a similar pattern . Histological analysis showed significant reduction of epidermal pigmentation , vessel numbers and mast cell counts . Type IV collagen staining was not observed in all specimens . CONCLUSION TXA decreased epidermal pigmentation associated with melasma and also reversed melasma-related dermal changes , such as vessel number and increased numbers of mast cells Background : Melasma is a common cause of facial hyperpigmentation with significant cosmetic deformity . Although several treatment modalities are available , none is satisfactory . Aim : To compare the therapeutic efficacy and safety of tranexamic acid ( TA ) microinjections versus tranexamic acid with microneedling in melasma . Material s and Methods : This is a prospect i ve , r and omised , open-label study with a sample size of 60 ; 30 in each treatment arms . Thirty patients were administered with localised microinjections of TA in one arm , and other 30 with  TA with microneedling . The procedure was done at monthly intervals ( 0 , 4 and 8 weeks ) and followed up for three consecutive months . Clinical images were taken at each visit including modified Melasma Area Severity Index MASI scoring , patient global assessment and physician global assessment to assess the clinical response . Results : In the microinjection group , there was 35.72 % improvement in the MASI score compared to 44.41 % in the microneedling group , at the end of third follow-up visit . Six patients ( 26.09 % ) in the microinjections group , as compared to 12 patients ( 41.38 % ) in the microneedling group , showed more than 50 % improvement . However , there were no major adverse events observed in both the treatment groups . Conclusions : On the basis of these results , TA can be used as potentially a new , effective , safe and promising therapeutic agent in melasma . The medication is easily available and affordable . Better therapeutic response to treatment in the microneedling group could be attributed to the deeper and uniform delivery of the medication through microchannels created by microneedling Background : Numerous therapeutic options have been tried in the management of  melasma .  Aims and Objectives : This prospect i ve r and omized study was planned to assess the efficacy of low potency triple combination ( TC ) cream ( TC-hydroquinone 2%/tretinoin 0.05%/fluocinolone 0.01 % ) versus glycolic acid ( GA ) peels/azelaic acid ( AA ) 20 % cream ( GA/AA ) combination in melasma . Material s and Methods : Forty patients with melasma were recruited into this study and r and omized into two groups . Group A consisting 20 patients received TC cream once a day for night time application for 3 months . Group B comprising of 20 patients received GA/AA 20 % cream combination for 3 months . The disease severity was monitored with digital photography , melasma area and severity index ( MASI ) score , which was calculated at baseline , 6 weeks and 12 weeks , and visual analog scale ( VAS ) score , which was calculated at baseline and 12 weeks . Results : Of 40 patients , 38 were completed the study . A significant reduction in MASI and VAS was recorded after 6 weeks and 12 weeks of treatment in both groups A and B ( P = 0.001 ) . However , there was no significant difference in the mean MASI scores between the two groups at baseline , 6 weeks and 12 weeks . Similarly , there was no difference in the mean VAS scores between the two groups at baseline and 12 weeks . Four patients in group A and 3 in group B experienced adverse effects such as irritation , dryness , and photosensitivity . Conclusion : Both low potency TC cream and GA/AA 20 % cream combination are effective in treating melasma among Indian patients Melasma is a common problem in Asians , but treatments have not been satisfactory . In the present study , we evaluated the efficacy of a new formula containing 0.1 % tretinoin , 5 % hydroquinone , and 1 % hydrocortisone ( RHQ ) in Korean patients with melasma . Twenty-five Korean females with therapy recalcitrant melasma applied RHQ on their faces for 4 months and were evaluated before and 4 weeks after treatment clinical ly and histologically . They were also evaluated clinical ly 4 months after treatment . To minimize unavoidable side effects ( erythema or peeling ) , we applied RHQ twice a week instead of the usual daily application . However , we obtained clinical and histological results comparable to other reports from white population s. Statistically significant depigmentation in clinical and histological studies and increased subepidermal collagen synthesis were observed in this study . These effects were seen as early as 4 weeks after treatment with RHQ . We used mMASI scoring , a modified version of the original MASI , to quantify the effects of RHQ more objective ly and easily Background : Melasma is a common acquired cause of facial hyperpigmentation with no definitive therapy . Tranexamic acid , a plasmin inhibitor , has demonstrated depigmenting properties and combining this oral drug with other modalities of treatment has shown promising results . Objectives : To compare the efficacy of a combination of oral tranexamic acid and fluocinolone-based triple combination cream with that of fluocinolone-based triple combination cream alone in  melasma among Indian patients . Material s and Methods : 40 patients of melasma of either sex attending to dermatology OPD were enrolled in this study . Participants were r and omly divided into two groups with 20 patients in each group . Group A patients were asked to apply the cream only and Group B patients received oral tranexamic acid 250 mg twice daily and applied a triple combination cream containing fluocinolone acetonide 0.01 % , tretinoin 0.05 % , and hydroquinone 2 % once daily 
    Output:
    
These results support the efficacy and safety of tranexamic acid , either alone or as an adjuvant to routine treatment modalities for melasma