Efficacy of intradermal injection of tranexamic acid and ascorbic acid versus tranexamic acid and placebo in the treatment of melasma: A split‐face comparative trial

Abstract Background and Aims Melasma is a common dermatologic disorder characterized by symmetrical hyperpigmented lesions on the face. Although various therapeutic options are available for melasma, its treatment remains challenging. The present study evaluated the safety and efficacy of intradermal microinjection of tranexamic acid (TA) plus ascorbic acid in treating melasma lesions compared with TA and placebo. Methods From September 2019 to May 2020, 24 patients with symmetrical melasma were enrolled in a prospective, double‐blind, split‐face, randomized controlled clinical trial. Each patient received 50 mg/ml TA and 50 mg/ml ascorbic acid for one side of the face (A) and 50 mg/ml TA and placebo for the other side (B) every 2 weeks for 12 weeks. The Melasma Area and Severity Index (MASI) score, Physician Global Assessment, and pain were measured at baseline and at 4, 8, 12, and 24 weeks. Statistical analysis was done using SPSS software version 16, and data were reported as mean ± standard deviation or median and interquartile range. χ 2 and Fisher's exact tests were used to test differences between the groups. Results Both groups experienced a significant decrease in MASI scores compared with the baseline. The MASI score was significantly less in the intervention group than the placebo group at the 8th and 12th weeks. However, burning pain was significantly more prominent in the intervention group. Conclusion Intradermal injection of ascorbic acid combined with TA can be beneficial in treating melasma. Currently, there are numerous treatment modalities for melasma. However, the results still vary, and satisfactory outcomes are yet to be reached.


| INTRODUCTION
Melasma is a common skin issue that results from melanogenesis dysfunction. It is particularly prominent in middle-aged women and is characterized by dark, hyperpigmented patches. The exact etiology of the disease is still unknown. However, factors like oral contraceptives, steroids, exposure to sunlight, pregnancy, hormone replacement therapy, ovarian tumors, and a stressful lifestyle may promote the development of the disease. 1,2 Therefore, the emergence of melasma is influenced by various factors and depends on environmental interactions, hormonal effects, and genetic susceptibility. Although melasma is found in all races, it is more prevalent in darker skin phototypes (Fitzpatrick skin III−V); it mainly affects people of Asian, Middle Eastern, Latin American, African, or Hispanic descent. 3 Even though melasma is primarily a cosmetic concern, this condition can dramatically impact the quality of life of affected patients and causes depression and frustration, reducing their psychosocial quality of life. In 2003, Balkrishnan and colleagues developed and evaluated the Melasma Quality of Life Index. It was reported that 65% of patients felt discomfort due to spots on their face, while 55% felt frustrated and 57% felt ashamed of their skin condition. 4 A literature review by Pawaskar et al. 5 also found that melasma has a severe impact on health-related quality of life and deleteriously affects patients' emotional wellbeing, social life, and physical health.
Nowadays, various treatment modalities are used to eliminate the lesions and prevent recurrences, including systematic and topical agents along with light-based therapies and lasers. 6 Broad-spectrum sunscreens, retinoic acid (tretinoin), azelaic acid, ascorbic acid, tranexamic acid (TA), 7 and chemical peels (such as salicylic acid and glycolic acid) are other treatment options have been described in the literature. 8 TA acts as an antifibrinolytic agent by inhibiting the tissue plasminogen activator. It has been shown to reduce blood loss and transfusion requirements in surgical procedures, including emergency trauma surgery, cardiovascular and spinal cord surgery, and hip and knee arthroplasty procedures. TA is also the only FDA-approved drug for heavy menstrual bleeding. The amount of TA used to treat melasma is much less than the antifibrinolytic dose. The hypopigmentation effect of TA is due to its antiplasmin activity. [9][10][11][12] According to the comparative study of the efficacy of intradermal and topical TA versus a triple combination of tretinoin 0.025%, hydroquinone 2%, and fluocinolone acetonide 0.01%, intradermal TA led to a significant decrease in the Melasma Area and Severity Index (MASI) score compared with the other groups. 13 In a split-face controlled trial by Saki et al., 14 a monthly intradermal injection of TA was associated with significantly reduced melanin content compared with topical hydroquinone during the first 4 weeks of treatment. However, after 20 weeks, the overall changes were not significant.
Topical and intradermal injection of ascorbic acid is another option for treating melasma lesions. Espinal-Perez et al. conducted a double-blind, randomized controlled trial evaluating the effect of 5% ascorbic acid versus 4% hydroquinone in treating melasma. In this study, both treatments showed satisfactory results without statistical differences in colorimetric measures. Nevertheless, those who received hydroquinone reported more side effects than those who received ascorbic acid (68.7% vs. 6.2% of patients). 15 The present study aimed to compare the efficacy and adverse effects of administering 50 mg/ml TA and 50 mg/ml ascorbic acid intradermally versus TA and placebo in treating facial melasma lesions. It should be noted that while TA has direct interactions with aspirin, epinephrine, acetaminophen, and 30 other drugs, it does not directly interact with ascorbic acid according to the Medscape and other approved websites. 16

| Study implementation
In the beginning, all participants were examined using a wood lamp to determine the melasma type (dermal, epidermal, or mixed). Demographic characteristics including sex, age, predisposing factors (pregnancy, exposure to ultraviolet rays, and oral contraceptives), family history of melasma, skin phenotypes, duration of the disease, type of melasma, affected body parts, and history of previous treatments were recorded.
In the following step, after administering a local anesthetic (lidocaine/prilocaine) and dressing on the face for 60 min, an intradermal injection was performed using a 1 ml syringe with intervals of 1 cm. To keep the distance of injections at 1 cm intervals, we measured the distances with a ruler and marked them with a pen. Thirty minutes after the procedure, the spots were cleaned with an alcohol pad. Each site was injected with 0.1 ml of the solution. Intradermal injection of drugs was performed by injecting the needle at an angle of 5−15°into the skin, leading to the formation of a wheal-like area on the skin. 18

| Outcome measures
Based on standard guidelines, the MASI was used to evaluate the involved area, darkness, and homogeneity of hyperpigmentation. For calculating the involved area (A), the right side of the forehead, the cheek, and the chin were calculated as 15%, 30%, and 5% of the whole face, respectively. Similar areas on the left side of the face were calculated in the same way, reaching a total of 100%. The final score ranged between 0 and 6 (0 = no involvement, 1 = 0%−9%, 2 = 10%−29%, beginning and end of the study. In this scale, 0%−25% improvement was reported as poor improvement, 26%−50% and 51%−75% were reported as fair and good improvement, respectively, and 76%−100% improvement in lightening was reported as an excellent improvement.
The patients' pain score was also recorded on a scale of 0−10, where 0 indicates no pain and 10 indicates the most severe pain.

| Statistical analysis
Statistical analysis was done using SPSS software version 16 (SPSS Inc.). A descriptive analysis was done on the demographic information, and data were reported as mean ± standard deviation (SD) or median and interquartile range (IQR) in case of nonparametric variables (e.g., duration of melasma). Frequencies were presented as numbers and percentages. χ 2 and Fisher's exact tests were used to test the differences between the categorical variables. A p value less than 0.05 was considered significant.

| RESULTS
Thirty female patients with bilateral symmetrical melasma lesions were eligible for the study (Figure 1). One patient was excluded from the study due to pregnancy, while another was excluded due to using other treatment modalities. Twenty-eight patients were enrolled in each group. Furthermore, two participants were also lost to follow-up due to transportation issues and the COVID-19 pandemic, and two participants discontinued the treatment due to injection pain.
Therefore, a total number of 24 patients with 24 sides of the face in each group were injected and analyzed.   (Figure 4). The results showed a statistically significant difference between the two groups (p = 0.003). According to the treatment complications in the studied patients, all patients in both groups reported pain and burning sensation in the injection site despite topical anesthesia. The mean pain score of patients in the ascorbic acid group was significantly higher at 0.82 (SD 0.11), while in the placebo group, the mean pain score was 0.50 (SD 0.10) (p = 0.01).

| DISCUSSION
Melasma is an acquired condition of the facial skin that mainly affects childbearing women. Clinically, it commonly affects the face in a centrofacial pattern of patches and macules with irregular borders.
The course of the disease is resistant to treatment and has a high recurrence rate; therefore, treatment of melasma still requires more evidence and a combination of effective pharmacological and nonpharmacological interventions. 6 Ascorbic acid is one of the suggested supplements in managing patients with melasma. It acts by chelating copper ions used in the cellular pigmentation process, thereby inhibiting melanogenesis. 19 This study aimed to evaluate the effectiveness of intradermal in- patients with epidermal melasma evaluated 20% trichloroacetic acid versus combination therapy of 5% ascorbic acid cream and trichloroacetic acid. The researchers showed that although both study groups experienced a significant reduction in MASI score, combination therapy also led to a significant reduction in MASI score.
Furthermore, those who received trichloroacetic acid experienced more side effects, though this was not significant. 7 Although the study used ascorbic acid topically, a finding similar to the present study was the effectiveness of adding ascorbic acid to the patient's medication regimen and using a combination treatment.

| CONCLUSION
The intradermal injection of a combination of TA and ascorbic acid could significantly reduce patients' MASI scores, and this improvement was sustained until 3 months. Currently, there are numerous treatment modalities for melasma. However, the results still vary, and satisfactory outcomes are yet to be reached. Thus, more research is needed to find the most efficient treatment.

ACKNOWLEDGMENTS
This study was extracted from the thesis of dermatology resident Dr.
Seyedeh Nasrin Molavi. This study was financially supported by the

CONFLICTS OF INTEREST
The authors declare no conflicts of interest.

ETHICS STATEMENT
The

DATA AVAILABILITY STATEMENT
The data that support the findings of this study are available from the corresponding author upon reasonable request.