The Relationship Between Melasma and Serum Zinc Levels

Melasma is a common pigmentary disorder, particularly prevalent in the Asian population. Often referred to as the "pregnancy mask" or chloasma, this condition disproportionately affects individuals of Asian, African, and Hispanic descent. 

Melasma presents as hyperpigmentation on sun-exposed areas of the face, notably the cheeks, forehead, nose, and supralabial regions. The condition appears as symmetrical macules and patches that can vary in colour from light to grey-brown, with irregular, jagged, and geographically defined borders. 

The exact pathophysiology of melasma remains unclear; however, it is believed that ultraviolet (UV) light stimulates plasmin activity in keratinocytes, leading to an increase in melanocyte-stimulating mediators such as arachidonic acid and melanocyte-stimulating hormones. Keratinocytes respond quickly to UV exposure, and the subsequent release of melanogenic and inflammatory factors triggers melanogenesis in fibroblasts. Additionally, UV radiation can cause damage to lipids, proteins, deoxyribonucleic acid (DNA), and reactive oxygen species (ROS). 

Common triggers for melasma include pregnancy, hormonal changes related to the uterus or ovaries, the use of oral contraceptives, liver disease, and the application of certain cosmetic products. Evidence supporting the notion that active melanocytes contribute to melasma includes increased vascularization in affected skin and heightened expression of angiogenic factors in the epidermis. 

Historically, the primary treatment strategies for melasma have focused on topical brighteners and rigorous sun protection. Complementary treatments may include chemical peels, dermabrasion, and laser therapies. treatments, all of which have shown variable responses. Numerous studies have explored the role of serum zinc in various skin conditions. Melasma not only leads to hyperpigmentation but also has a significant negative impact on the quality of life for those affected. Research indicates that 65% of patients with melasma feel discomfort related to their condition either constantly or frequently. Additionally, 57% of patients report feelings of humiliation, 55% experience annoyance, and 42% indicate that melasma affects their interpersonal interactions. 

Melasma is classified based on both its location and the depth of pigment involvement. The three subtypes include centrofacial, malar, and mandibular, which are determined by the distribution of pigmentation on the face. To evaluate the depth of melasma, Wood's lamp illumination is often utilized, enabling further classification into epidermal, dermal, mixed, and indeterminate types. However, this diagnostic method does not always correlate with histological findings, and epidermal melasma is frequently misidentified as dermal melasma. 

The facial involvement and treatment challenges associated with melasma disproportionately affect patients' quality of life. Despite the multitude of potential triggers for hyperpigmentation, a comprehensive understanding of the underlying mechanisms and effective treatments remains crucial for improving patient outcomes.

The tyrosinase-related proteins (TRPs), specifically TRP-1 and TRP-2, also play significant roles in pigmentation disorders. Tyrosinase is a critical enzyme involved in melanogenesis, and its regulation is essential for maintaining normal skin pigmentation. In melasma, the overproduction of pigment occurs due to a disruption in the homeostatic systems that typically regulate skin colour. 

Traditional treatment options for melasma include topical medications and chemical peels. However, due to the challenging nature of the condition, many patients seek non-traditional therapies such as laser and light treatments. Various approaches have been explored for managing melasma, including the use of lasers and other light therapies. The most commonly employed laser and light treatments today include intense pulsed light (IPL), low fluence Q-switched lasers, and non-ablative fractionated lasers. 

The goal of this research is to determine whether there is a relationship between melasma and zinc deficiency. Zinc deficiency is a significant concern in both industrialized and developing nations, with reported prevalence rates ranging from 11.3% to 80%. For instance, it is estimated that 74.3% of the population in Indonesia suffers from zinc deficiency. 

Zinc acts as an antioxidant and anti-inflammatory agent, playing a crucial role in the regeneration of damaged skin. It is also essential for the endocrine system, contributing to the maintenance of healthy thyroid function and homeostasis. Thyroid hormone secretion depends on adequate levels of zinc, which is vital for the proper functioning of numerous organs. 

The majority of literature supports the idea that measuring serum zinc levels is beneficial for assessing deficiency. In this study, the atomic absorption spectrophotometry (AAS) method was employed due to its simplicity, sensitivity, accuracy, and rapid results.

Place of Study: AVBRH Sawangi (Meghe) Wardha, Outpatient Dermatology Department.

Data Collection Timeline: The research was conducted over a period of one and a half years, from December 2020 to April 2022.

Study DesignCase-Control Study.

Study Setting: This study included patients diagnosed with melasma who were over the age of 20 and visited the AVBRH Outpatient Department of Dermatology, Venereology, and Leprosy at Jawaharlal Nehru Medical College in Sawangi, Wardha, during the study period from December 2020 to April 2022.

Sample Size

Formula for sample size with acceptable margin of error:

n = [Zα/2.2P (1-P)

d2

Where:

Zα/2 = the level of significance at 5% (i.e. 95% confidence interval=1.96)

P = Prevalence of melasma in pregnancy =15.8% =0.158

d = Desired error of margin =7% =0.07

n= (1.96)2x 0.158 x (1-0.158)

(0.07)2

= 78

~ n = 78 patients

Formula Reference: Dr. Sanjay Zodpey et al, workshop on sample size consideration in

medical research, August 20-22, 1999.

A total of 132 patients aged over 20 years, diagnosed with melasma, were enrolled in the study after obtaining informed consent. Among these, there were 78 cases of melasma and 54 control subjects attending the AVBRH Outpatient Department of Dermatology, Venereology, and Leprosy at Jawaharlal Nehru Medical College, Sawangi, Wardha.

1. Patients diagnosed with melasma.
2. Patients willing to participate in the study.
3. Female patients aged over 20 years.
4. Patients who are pregnant or lactating, or those currently using hormonal contraceptives.

1. Use of hydroquinone or tranexamic acid during the research period or in the three months prior to enrollment.
2. Presence of any endocrinological disease.
3. Use of hormone replacement therapy.
4. Personal or family history of any of the following: autoimmune diseases, blood clotting disorders, circulatory system diseases, retinal disorders, or kidney diseases.

Melasma patients aged over 20 years were enrolled in the study between December 2020 and April 2022. Prior to the commencement of the study, permission was obtained from the Institutional Ethics Committee. All participating patients provided written informed consent. 

Demographic information was collected, including the following variables:

• Age
• Gender
• Socioeconomic status
• Marital status
• Occupation
• Precipitating factors for melasma
• Duration of melasma
• Previous treatments received
• Skin phenotype (Fitzpatrick classification)
• Type of melasma (e.g., centrofacial, malar, mandibular)

Blood samples were then collected from all enrolled participants for serum zinc level analysis. Serum zinc levels were measured using atomic absorption spectrophotometry (AAS) to assess any potential deficiencies.

Each case and control participant received a 5 mL intravenous blood sample. The serum supernatant was then separated by centrifugation at 1700 g for 10 minutes and subsequently frozen at -40°C for further analysis. Blood samples were drawn using zinc-free plastic syringes and collected in zinc-free centrifugation tubes to prevent contamination [1,2].

Serum zinc levels were measured using the atomic absorption spectrophotometry (AAS) method. Zinc deficiency was defined as serum zinc levels less than 70 µg/dL [3-10].

Statistical analysis

All patient data were collected using a pro forma and entered into an Excel spreadsheet. Descriptive statistics, including mean and standard deviation, were utilized to summarize quantitative data. Frequency and percentage were employed to describe qualitative data. The aggregated data were presented in various formats, including tables, figures, bar charts, and pie charts (Table 1)

Table 1: Comparison of the mean age of participants.

Mean ± SD:

• Melasma Cases: 38.53 ± 8.10 years (Range: 22-61 years)
• Control Group: 35.35 ± 12.98 years (Range: 16-70 years)
• Overall Mean Age: 37.23 ± 10.45 years (Range: 16-70 years)

Statistical Analysis:

• χ2-value: 19.88
• p-value: 0.0005 (Significant)

Observations

1. The age group most affected by melasma in this study is 31-40 years, accounting for 46.15% of cases. 
2. The mean age of melasma patients (38.53 years) was statistically significantly higher than that of the control group (35.35 years).

Table 1 shows the age distribution of the study participants. It was observed that the majority of participants were in the age group of 31-40 years (46.15%), followed by the 41-50 years group (29.49%) and the 20-30 years group (16.67%). Only 6 patients (7.69%) were in the age group of more than 50 years. The mean age of the patients was 38.53 years in the melasma cases, compared to 35.35 years in the control group, with no significant mean difference between the two groups.

For statistical analysis, both descriptive and inferential statistics were utilized using the Statistical Package for the Social Sciences (SPSS) version 27.0 and GraphPad Prism version 7.0 [11-15]. The Chi-square test was applied to categorical data, while the z-test for the difference in means was used to compare serum zinc levels between the case and control groups. A significance level of 0.05 was established for all statistical tests (Figure 1).

 Figure 1: Comparison of mean age of participants.

Ethical approval for this study was obtained from the Institutional Ethics Committee. All participants were provided with a detailed explanation of the study's objectives, procedures, and potential risks. Informed consent was obtained in writing from all participants prior to their inclusion in the study [16]. Confidentiality of patient data was strictly maintained, and all procedures were conducted in accordance with the Declaration of Helsinki. Participants had the right to withdraw from the study at any time without any repercussions on their medical care (Table 2) (Figure 2). 

Table 2: Comparison of the mean age of participants.

Table 3: Mean Comparison of Zinc Levels Between the Groups

Figure 2: Shows mean comparison of Zinc levels between the groups. 

Table 5: Mean Level of MASI Score Among Participants and MASI Score in Patients with Zinc Deficiency. 

The baseline characteristics of the recruited patients are presented in Table 1, illustrating the age distribution of the study participants. The majority of participants fell within the age group of 31–40 years (46.15%), followed by the 41–50 years group (29.49%) and the 20–30 years group (16.67%). Only 6 patients (7.69%) were aged over 50 years. The mean age of patients in the melasma group was 38.53 years, while the control group had a mean age of 35.35 years, with no statistically significant difference observed between the two groups [1-5]. 

As shown in Table 2, there was a notable difference in the mean ages of the case and control groups. The mean age of melasma cases was 38.53 ± 8.10 years, compared to 35.35 ± 12.98 years for the controls (p > 0.05).

Among the total of 78 melasma patients, the distribution of the melasma patterns is detailed in Table 3. The centrofacial type was observed in 53.85% of patients, while the malar type was present in 46.15%. Notably, no cases of the mandibular type of melasma were reported in this study [17-25]. 

Zinc deficiency among the case and control groups is illustrated in Table 4. There was a significant difference in the distribution of zinc deficiency levels between the two groups. Specifically, 12 melasma patients exhibited low serum zinc levels, compared to only 3 patients in the control group [26-27]. 

The comparison of mean serum zinc concentrations between the two groups is presented in Table 4. The mean serum zinc level in the melasma cases was found to be significantly lower (78.23 ± 27.79 µg/dL) than that in the control group (104.91 ± 45.57 µg/dL), with a p-value of < 0.01. 

The mean Melasma Area and Severity Index (MASI) score for the study participants is presented in Table 5. The mean MASI score among the melasma cases was found to be 10.49 ± 2.36, with a minimum score of 7.20 and a maximum score of 16.10. The Z-value was 1.56, with a p-value of 0.12, indicating that the difference was not statistically significant.

Melasma, also known as chloasma, is a frequently acquired hyper melanosis predominantly affecting female patients within the Asian population. This condition is particularly common among women with Fitzpatrick skin phototypes IV–VI, as compared to males. Melasma typically manifests as macules or patches on sun-exposed areas of the face, characterized by uneven, serrated, and geographical borders, with colour variations ranging from light to dark brown. 

The exact aetiology of melasma remains unclear; however, several factors have been implicated in its pathophysiology. These include genetic predisposition, excessive sun exposure, hormonal influences—particularly in women-pregnancy, oral contraceptives, anticonvulsants, thyroid disorders, and certain cosmetic products [19,20]. 

The present investigation aimed to compare the serum zinc levels of melasma patients with those of healthy controls to determine if a correlation exists between the two groups. The conclusion was drawn by analysing the estimated serum zinc levels in melasma patients and other skin disorders against those of healthy individuals.

A total of 132 participants were included in the study, comprising 78 individuals with melasma and 54 with other skin conditions serving as controls. The age distribution of the participants revealed that the majority (46.15%) fell within the 31 to 40 age range, while only six patients (7.5%) were over 50 years of age. The average age of melasma patients was found to be 38.62 ± 8.32 years, compared to 33.55 ± 13.08 years for the control group, indicating a statistically significant difference. 

In a study by Rambe PS et al., it was observed that 36.7% of patients fell within the age group of 46-55 years, 43.3% were aged 36-45 years, 13.3% were between 56-65 years, and 6.7% were in the 26-35 age range [12].

Regarding the distribution of melasma types, our findings indicated that the majority of patients presented with the centro-facial type (53.7%). This aligns with the study by Mogaddam et al., which reported a prevalence of 72% for the centro-facial type among their patients. Conversely, we observed that 46.3% of our patients had malar melasma, a figure notably higher than Mogaddam et al.’s report of only 3.2% for this category. Furthermore, similar to our study, Mogaddam et al. found that no patients exhibited the mandibular pattern. Additionally, they reported that 24.6% of patients demonstrated both centro-facial and malar distribution patterns [21-25]. 

Upon assessing the Melasma Area and Severity Index (MASI) score, the mean score among the cases was found to be 10.30±2.26, with a minimum score of 7.20 and a maximum score of 16.10. There was a notable difference in zinc levels between the case and control groups. Specifically, 12 patients (15.38%) in the melasma cases exhibited low zinc levels, while only 3 patients (5.38%) in the control group were found to have low serum zinc levels. 

Comparative analysis revealed that the mean serum zinc concentration among the melasma cases was significantly lower (78.23±27.79 μg/dL) than that of the control group (104.91±45.57 μg/dL), with a p-value of less than 0.01, indicating statistical significance. 

In contrast, a study by Sekarnesia IS et al. reported that the mean serum zinc levels for patients with melasma were 10.25±1.89 μmol/L, while those without melasma had slightly higher levels at 10.29±1.46 μmol/L (p=0.901) [27,28]. This study suggested that the difference in zinc levels between the two groups was not statistically significant. Furthermore, it was noted that there was no significant difference in blood zinc levels between melasma and non-melasma groups, regardless of thyroid function status. 

Another investigation by Mogaddam MR et al. ndicated that 45.8% of individuals with melasma exhibited low serum zinc levels, compared to 23.7% in those without the condition. This finding is in line with our results, reinforcing the potential association between zinc deficiency and melasma. Additionally, Rambe PS et al. reported average blood zinc levels of 54.31 μg/dL, 53.56 μg/dL, and 47 μg/dL in confirmed cases of melasma, further supporting the notion that low zinc levels may be a common characteristic among melasma patients. 

Despite the observed differences in serum zinc levels between melasma patients and controls, our study found no significant correlation between melasma severity, as measured by the MASI score, and serum zinc concentrations. This finding aligns with the results of other studies, such as that conducted by Rostami Mogaddam et al., which indicated that while 45.8% of patients with melasma had low serum zinc levels compared to 23.7% of the control group, there was no direct correlation between the severity of melasma and zinc deficiency [27]. 

Zinc has been recognized for its roles as an anti-inflammatory, antioxidant, and skin barrier-supporting agent, making it a valuable component in the management of various dermatological conditions, including melasma [28-32]. Its presence in topical treatments, particularly in sunscreens, underscores its potential benefits for skin health and photoprotection. However, the lack of correlation between melasma severity and serum zinc levels suggests that while zinc deficiency may be prevalent among melasma patients, it may not directly influence the severity of the condition.

• Study Design: This was a hospital-based study rather than a population-based study, which may limit the generalizability of the findings to a broader population.
• Follow-Up: Long-term follow-up of patients was not feasible, which restricts the ability to assess the durability of serum zinc level changes and their potential impact on melasma over time.
• Sample Size: Due to the expense of serum zinc level testing, only a moderate number of patients could be included in the study. This limited sample size may affect the statistical power and robustness of the results.
• COVID-19 Impact: During the study period, the use of N95 masks by patients, prompted by the COVID-19 pandemic, may have inadvertently reduced cumulative sun exposure, which is a known exacerbating factor for melasma, thus potentially reducing the incidence of melasma.
• Lack of Supplementation: Patients with reduced zinc levels were not managed with zinc supplements, which may limit the ability to draw conclusions regarding the therapeutic potential of zinc supplementation in melasma treatment.

The findings of this study suggest a potential link between melasma and low serum zinc levels. Patients with melasma exhibited significantly lower blood zinc levels compared to healthy controls, indicating that zinc deficiency may play a role in the pathogenesis of melasma. This study underscores the importance of evaluating zinc deficiency in patients with melasma. Future research should focus on assessing the therapeutic effects of zinc supplementation in managing melasma.

1. Basit H, Godse KV, Al Aboud AM (2021) Melasma. In: StatPearls. StatPearls Publishing, USA.
2. Handel AC, Miot LDB, Miot HA (2014) Melasma: a clinical and epidemiological review. An Bras Dermatol 89: 771-782.
3. Freitag F, Cestari T, Leopoldo L, Paludo P, Boza J (2008) Effect of melasma on quality of life in a sample of women living in Southern Brazil. J Eur Acad Dermatol Venereol 22: 655-662.
4. Kim EH, Kim YC, Lee E-S, Kang HY (2007) The vascular characteristics of melasma. J Dermatol Sci 46: 111-116.
5. Grimes PE, Yamada N, Bhawan J (2005) Light microscopic, immunohistochemical, and ultrastructural alterations in patients with melasma. Am J Dermatopathol 27: 96-101.
6. Trivedi MK, Yang FC, Cho BK (2017) A review of laser and light therapy in melasma. Int J Women’s Dermatology 3: 11-20.
7. Lee A-Y (2015) Recent progress in melasma pathogenesis. Pigment Cell Melanoma Res 28: 648-660.
8. Sekarnesia IS, Sitohang IBS, Agustin T, Wisnu W, Hoemardani ASD (2020) A comparison of serum zinc levels in melasma and non-melasma patients: a preliminary study of thyroid dysfunction. Acta Dermatovenerol Alp Pannonica Adriat 29: 59-62.
9. Rodríguez-Arámbula A, Torres-Álvarez B, Cortés-García D, Fuentes-Ahumada C, Castanedo-Cázares JP (2015) CD4, IL-17, and COX-2 Are Associated With Subclinical Inflammation in Malar Melasma. Am J Dermatopathol 37: 761-766.
10. Bak H, Lee HJ, Chang S-E, Choi J-H, Kim MN, et al. (2009) Increased expression of nerve growth factor receptor and neural endopeptidase in the lesional skin of melasma. Dermatol Surg 35: 1244-1250.
11. Rajaratnam R, Halpern J, Salim A, Emmett C (2010) Interventions for melasma. Cochrane Database Syst Rev 7: CD003583.
12. Ogbechie-Godec OA, Elbuluk N (2017) Melasma: an Up-to-Date Comprehensive Review. Dermatol Ther (Heidelb) 7: 305-318.
13. Rendon MI (2019) Hyperpigmentation Disorders in Hispanic Population in the United States. J Drugs Dermatol 18.
14. Passeron T, Genedy R, Salah L, Fusade T, Kositratna G, et al. Laser treatment of hyperpigmented lesions: position statement of the European Society of Laser in Dermatology. J Eur Acad Dermatol Venereol 33: 987-1005.
15. Zubair R, Lyons AB, Vellaichamy G, Peacock A, Hamzavi I (2019) What’s New in Pigmentary Disorders. Dermatol Clin 37: 175-181.
16. Tamega A de A, Miot LDB, Bonfietti C, Gige TC, Marques MEA, et al. (2013) Clinical patterns and epidemiological characteristics of facial melasma in Brazilian women. J Eur Acad Dermatol Venereol 27: 151-156.
17. Ortonne JP, Arellano I, Berneburg M, Cestari T, Chan H, et al. (2009) A global survey of the role of ultraviolet radiation and hormonal influences in the development of melasma. J Eur Acad Dermatol Venereol 23: 1254-1262.
18. Hexsel D, Lacerda DA, Cavalcante AS, Filho CASM, Kalil CLP V, et al. Epidemiology of melasma in Brazilian patients: a multicenter study. Int J Dermatol 59: 178-185.
19. Goandal NF, Rungby J, Karmisholt KE (2022) The role of sex hormones in the pathogenesis of melasma. Ugeskr Laeger 184: 10210769.
20. Hernando B, Ibarrola-Villava M, Fernandez LP, Peña-Chilet M, Llorca-Cardeñosa M, et al. (2016) Sex-specific genetic effects associated with pigmentation, sensitivity to sunlight, and melanoma in a population of Spanish origin. Biol Sex Differ 7: 17.
21. Mogaddam MR, Ardabili NS, Alamdari MI, Maleki N, Danesh MA (2018) Evaluation of the serum zinc level in adult patients with melasma: Is there a relationship with serum zinc deficiency and melasma? J Cosmet Dermatol 17: 417-422.
22. Duarte I, Campos Lage AC (2007) Frequency of dermatoses associated with cosmetics. Contact Dermatitis 56: 211-213.
23. Damevska K (2014) New aspects of melasma. Serbian J Dermatology Venerol 6 :5-18.
24. Kwon S-H, Hwang Y-J, Lee S-K, Park K-C (2016) Heterogeneous Pathology of Melasma and Its Clinical Implications. Int J Mol Sci 17.
25. Gupta A, Gover M, Nouri K, Taylor S (2016) The treatment of melasma: A review of clinical trials. J Clin Aesthet Dermatol 9: 50-64.
26. Cunha MG, Paravic FD, Machado CA (2015) Histological changes of collagen types after different modalities of dermal remodeling treatment: a literature review. Surg Cosmet Dermatol 7: 285-292.
27. Jang YH, Lee JY, Kang HY, Lee E-S, Kim YC (2010) Oestrogen and progesterone receptor expression in melasma: an immunohistochemical analysis. J Eur Acad Dermatol Venereol 24: 1312-1326.
28. Noh TK, Choi SJ, Chung BY, Kang JS, Lee JH, et al. (2014) Inflammatory features of melasma lesions in Asian skin. J Dermatol 41: 788-794.
29. Park K, Kim I (2017) Pathogenesis of Melasma. In: Melasma and Vitiligo in Brown Skin Page no. 21-31.
30. Kang HY, Lee JW, Papaccio F, Bellei B, Picardo M (2021) Alterations of the pigmentation system in the aging process. Pigment Cell Melanoma Res 34: 800-813.
31. Phansuk K, Vachiramon V, Jurairattanaporn N, Chanprapaph K, Rattananukrom T (2022) Dermal Pathology in Melasma: An Update Review. Clin Cosmet Investig Dermatol 15: 11-19.
32. Kapoor R, Dhatwalia SK, Kumar R, Rani S, Parsad D (2020) Emerging Role of Dermal Compartment in Skin Pigmentation: Comprehensive Review. J Eur Acad Dermatology Venereol 34: 2757-2765.