|Year : 2021 | Volume
| Issue : 2 | Page : 86-94
Study of contact sensitivity to cosmetic allergens in melasma
Sonali Verma1, Rashmi Sarkar2, Bijaylaxmi Sahoo1
1 Department of Dermatology, Maulana Azad Medical College & Associated Lok Nayak Hospital, Bahadur Shah Zafar Marg, New Delhi, India
2 Department of Dermatology, Lady Hardinge Medical College & Associated SSK and KSCH Hospitals, New Delhi, India
|Date of Submission||10-May-2021|
|Date of Decision||08-Jun-2021|
|Date of Acceptance||15-Jun-2021|
|Date of Web Publication||22-Jul-2021|
Dr. Rashmi Sarkar
Department of Dermatology, Lady Hardinge Medical College and Associated SSK and KSC Hospitals, New Delhi, 110002
Source of Support: None, Conflict of Interest: None
Introduction: Melasma is a relatively common hypermelanotic disorder characterized by symmetrical light to gray-brown macules and patches involving photoexposed areas. Multiple factors have been implicated in the etiopathogenesis, including genetic factors, UV radiation, pregnancy, oral contraceptive pills (OCPs), thyroid dysfunction, and cosmetics. However, the role of cosmetics has not been well studied in melasma patients. The present study was designed to study the contact sensitivity to cosmetic allergens in patients with melasma. Material and Methods: Thirty patients with and thirty without melasma who visited Dermatology OPD between October 2015 and March 2017 were recruited according to selection criteria and were sequentially patch and photopatched with Indian cosmetic and fragrance series. Results: The mean age of melasma patients was 32.10 ± 6.62 years with female to male ratio of 1.72:1. Sixteen (53%) patients were found to show positive reactions on patch and photopatch testing with Indian cosmetic and fragrance series. Among 32 allergens tested, 15 allergens were found eliciting positive reaction. Thiomersol was the most common contact sensitizer eliciting positive reaction in six (38%) patients, followed by cetrimide, hexamine, and sorbitan each in three patients (19%). In the control group, only one (3.3%) subject showed positive contact allergy pattern. The results were significant (P < 0.001). Conclusion: A possible consideration of the pigmented cosmetic dermatitis and cosmetic contact sensitivity is recommended in the etiologic factors of melasma especially, in nonpregnancy/lactation induced melasma or when it is not associated with hormone therapy. Contact sensitizers might also have a role in melasma that is recalcitrant to all standard therapies.
Keywords: Contact sensitivity, etiology, melasma, patch testing
|How to cite this article:|
Verma S, Sarkar R, Sahoo B. Study of contact sensitivity to cosmetic allergens in melasma. Pigment Int 2021;8:86-94
| Introduction|| |
Melasma is a common disorder of hyperpigmentation characterized by symmetrical light to gray-brown macules and patches involving photoexposed areas. There is a propensity for involvement of the cheeks, forehead, upper lip, chin, and nose. The disease is more commonly observed in women. Men represent only 20.5% of cases and demonstrate the same clinicohistological characteristics as do women. The disease is more prevalent in darker individuals (skin types IV to V), especially women of Hispanic, Asian, and African origin who live in areas with intense UV radiation., The true incidence of melasma is unknown, however, the prevalence varies from 0.25 to 4% in South Asia. In India, it is one of the most common hyperpigmentary disorders, but exact prevalence in our country is not known. The clinical patterns of hyperpigmentation recognized in patients with melasma are centrofacial, malar, and mandibular., The Melasma Area and Severity Index (MASI) is the most commonly used outcome measure to determine severity of melasma and response during therapy.,
Though the precise cause of melasma remains elusive, multiple factors have been postulated in its etiopathogenesis, including genetics, exposure to UV radiation, pregnancy, oral contraceptives, oestrogen–progesterone therapies, thyroid dysfunction, ovarian dysfunction, cosmetics including mustard oil application, and so on.,, However, the role of cosmetics has been scarcely studied.
A study was conducted by Prabha et al., in which 67 patients of melasma were patch tested with Indian cosmetic and fragrance series and Indian sunscreen series. About 43% patients showed positive reactions, with cetrimide (52%) being most common contact sensitizers, followed by gallate mix (31%) and thiomersol (24%). Also, in a study by Sarkar et al., mustard oil was found to be a common applicant in men with melasma, although its role had not been not confirmed by patch testing. A study by Verallo-Rowell et al. has proposed that melasma patients may have photocontact dermatitis to various external factors (e.g., preservatives, fragrances present in cosmetics) that can be induced/aggravated even by low energy visible light without any antecedent erythema. This aspect of cosmetic contact sensitivity in melasma requires a more detailed study. The present study was designed to study the contact sensitivity to cosmetic allergens in patients with melasma.
| Material and Methods|| |
A cross-sectional study was conducted in Dermatology outpatient department at Lok Nayak Hospital in New Delhi between October 2015 and March 2017. Cases and controls were recruited as per predefined selection criteria [Table 1]. Thirty patients with a clinical diagnosis of melasma were selected as cases. Thirty age and sex matched subjects were selected as controls. An informed consent was obtained and the data regarding demographic profile, duration and evolution of lesions, sun exposure, use of any cosmetics, occupational history, photosensitivity/other associated symptoms, general physical examination, localization and morphology of lesions, and modified MASI was noted in a predesigned proforma.
Patients were sequentially patch and photopatch tested with Indian cosmetic and fragrance series (manufactured by Systopic India), para-phenylenediamine (PPD, a common ingredient in hair color dyes), and patients’ own cosmetics such as coconut oil and mustard oil [Table 2]. The allergens were stored at 2°C to 8°C and Finn chambers at room temperature. Petroleum was used as patch test vehicle. The patch tests were placed on the table with aluminum Finn chambers facing up; the allergens then were placed on the respective numbered chambers such that about 2 to 3 mm allergen was placed centrally. The test materials were applied to the participant’s upper back in duplicate and left for 48 hours. The patients were instructed to take care that the patch test units remain in place for 48 hours, not to wet the back during this period, to avoid tight underclothes, exercise, or other strenuous activity, to avoid friction, rubbing over the strips, excessive sun exposure, scratching, and to report back after 48 hours, when patches were removed and simultaneously the sites were marked and numbered with permanent marker to clearly demonstrate the different sites. The results were noted 1 hour after removing the patches and photographs were taken. Following this, the sites of one duplicate on the left upper side of the back were covered with opaque material, while those of the other were irradiated with 10 J/cm2 Ultraviolet A (UVA). The source of UVA was a phototherapy machine manufactured by V Care India UV therapy V2.0 consisting of 12 (100W) of UVA and Ultraviolet B (UVB) each. Patients back was placed 15 cm from the tubes. After irradiation, both sides were covered with opaque material and reading was taken after another 48 hours (day 4, i.e., 96 hours) and also on day 5, that is, 120 hours (if required). Grading of the patch and photopatch test was done by International Contact Dermatitis Research Group criteria [Table 3]. Interpretation of tests was done according to criteria mentioned in [Table 4]. The relevance of the positive tests was defined as “possible” when circumstance for contact was likely to occur, ‘probable’ when the contact could be verified with products containing the putative allergen, ‘definite’ when patch test to the product/object is present, and ‘past’ when reaction could be explained by a previous and unrelated episode of contact dermatitis.,,
All the data obtained were subjected to statistical analysis and relevant statistical tests were applied. Data were entered in Microsoft Excel and then analyzed in SPSS version 17. All quantitative variables were estimated using measures of central location (mean, median). Normality of data was checked by measure of skewness. For normally distributed data, variables were compared using Student t test. For non-normal distribution, data were compared using Wilcoxon signed rank test and Mann–Whitney test. Qualitative variables were described with frequencies and proportions and compared using chi-square or Fisher exact test (wherever applicable). P < 0.05 was considered significant.
| Results|| |
The study population consisted of 30 patients with melasma, and an equal number of controls matched for age and sex. The age of the patients with melasma ranged from 20 to 45 years. Mean age of the study population was found to be 32.10 ± 6.62 years. There was a female preponderance with 19 (63%) females and 11 (37%) males and a female to male ratio of 1.72:1. The range of duration of disease varied from 3 months to 17 years, with a mean of 2.95 years. Three (10%) patients had history of itching, one (3.3%) had photosensitivity, whereas one (3.3%) had photosensitivity, itching, and burning. Twenty-one (70%) patients had history of sun exposure exceeding 1 hour/day, five (17%) patients had history of exposure less than 1 hour, and four (13%) had no sun exposure throughout the day. In the study, malar melasma was the most common pattern and was seen in 16 (53%) patients, whereas centrofacial pattern was seen in 10 (34%) patients. Combination pattern was observed only in four (13%) patients. Interestingly, mandibular pattern was not seen alone, but was observed in combination with other patterns. The mean modified MASI observed in the study was 5.64 ± 4.04. The minimum observed value was 1.2, whereas the maximum observed value was 18.6. There was no statistically significant difference in mean modified MASI among male and female patients [Table 5].
The leading topical agents used by patients with melasma were mustard oil and henna (16 patients each) (53%), followed by medicated soaps in 15 patients (50%), commercial fragrances and cosmetic creams in 14 patients (46.67%), hair dyes in 10 patients (33%), coconut oil in nine patients (30%), and turmeric/gram flour in four patients (13%) only.
Surprisingly, among 30 melasma patients, a total of 16 (53%) patients were found to show positive reactions on patch and photopatch testing with Indian cosmetic and fragrance series. Twelve (40%) patients showed contact allergy pattern to thiomersol, hexamine, triclosan, musk mix, rose oil, sorbitansesquioleate, polyoxyethylenesorbitanoleate (tween20), kathon cg, butylated hydroxylanisole (BHA), and mustard oil. Two (7%) patients showed contact photoallergy pattern to thiomersol, cetrimide, and isopropyl myristate and another two (7%) patients showed both contact photoallergy and contact allergy pattern to hexamine, PPD, benzyl salicylate, and coconut oil [Figure 1]. Out of the 14 patients who did not show any contact/photocontact allergy, adhesive tape reaction and angry back phenomenon were seen in one (3%) patient each. figuAmong 32 allergens tested, 15 allergens were found eliciting positive reaction in our study [Figure 2]. Thiomersol was the most common contact sensitizer eliciting positive reaction in six (38%) patients, followed by cetrimide, hexamine, and sorbitan each in three patients (19%). Only 3 of the 16 patients showed positive reaction from their own cosmetics such as PPD, coconut oil, and mustard oil. Benzyl salicylate, triclosan, musk mix, rose oil, tween 20, BHA, isopropyl myristate, and kathon cg each was found to elicit positive reactions in 7% patients [Figure 3]a,b and [Figure 4]a,b.
|Figure 1 Interpretation of patch and photopatch testing in melasma patients|
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|Figure 2 Graph depicting various cosmetic contact sensitizers found to elicit positive reaction on patch and photopatch testing|
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|Figure 3 Positive patch test from cetrimide in a patient with centrofacial melasma. (a) Patient with centrofacial melasma. (b) Positive patch test in the patient from cetrimide|
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|Figure 4 Positive patch test from thiomersol in a patient with malar melasma. (a) Patient with malar melasma. (b) Positive patch test in the patient from thiomersol|
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In comparison, in the control group, that is, no melasma group, only one (3.3%) subject showed positive contact allergy pattern to PPD. Rest 29 (97%) subjects did not develop any positive reaction pattern to any of the allergens when patch and photopatch tested. The results were significant (P < 0.001) [Table 6], Figure 5].
| Discussion|| |
Melasma is a common acquired disorder of hyperpigmentation characterized by irregularly shaped, somewhat symmetrical, light to gray-brown macules involving photoexposed areas especially the forehead, cheeks, nose, and chin. But sometimes cervical region and less commonly sternal region and arms may also get affected.
The exact etiology of melasma has always remained an enigma. However, various factors have been considered in the etiopathogenesis of the disorder, including genetic factors, exposure to UV radiation, pregnancy, oral contraceptives, oestrogen–progesterone therapies, thyroid dysfunction, ovarian dysfunction, cosmetics including mustard oil application, phototoxic drugs, and anticonvulsant drugs.,, However, cosmetics have been sparsely studied in context to the etiology of melasma.
There are three distinctly recognized clinical patterns: centrofacial, malar, and mandibular. The exact proportion of each of clinical patterns in our population is not known, but in a multicenter study conducted by Krupashankar et al., the most commonly observed pattern was centrofacial (42%), followed by malar (39%) and mandibular patterns (1%). Similarly, in another study, conducted on 312 Indian patients, the centrofacial pattern (54.44%) was observed as most common, followed by malar (43%) and mandibular patterns (1.6%). However, in the present study, malar melasma was the most common pattern observed on clinical examination. This pattern was seen in 57% of the patients, whereas centrofacial pattern was observed in 33% of the patients. Also, Sarkar et al. in 2010 and Choubey et al. in 2017 reported that malar pattern was most common in males and was diagnosed in 25 (61%) of 41 males, which was in concordance with our study. In addition, our study had a high proportion of affected males, hence explaining malar melasma to be the most frequent pattern observed. Similar pattern was observed in a study by Goh et al., where malar pattern percentage was as high as 89% followed by centrofacial pattern (8%). Combination pattern accounted for only 10% of the patients in our study. Though rare, combination patterns were experienced in up to 18% patients in a study conducted by Krupashankar et al. also. Mandibular pattern was not observed in any of the patients in our study. Mandibular melasma is usually least frequently reported in patients of melasma. Similarly, in the study by Sarkar et al.  in 2010, mandibular melasma was diagnosed in only four (9.7 %) male patients of melasma. The mean modified MASI observed in the study was 5.64 ± 4.04. The minimum observed value was 1.2, whereas the maximum observed value was 18.6. Modified MASI had no significant correlation with duration of disease or sex.
In the modern era, individuals have a quenching thirst to improve their skin appearances. This has led to increase in the usage of various cosmetics products throughout the world. Basically, cosmetics are the compound mixtures of fragrances, preservatives, emulsifiers, stabilizers, various lipids, and alcohols. Various ingredients in cosmetics (sorbitan, PPD, balsam peru, cetostearyl alcohol, musk mix, vanillin, rose oil, triclosan, parabens, etc.) are capable of causing sensitization of the skin, leading to increased incidence of cosmetic dermatitis, primary irritant reactions, allergic contact dermatitis, photoallergic contact dermatitis, contact urticaria, pigment alteration, photosensitivity, and so on., The role of cosmetics in the causation of melasma has so far been poorly delineated.
The leading topical agents used by patients in our study were mustard oil and henna (53% each), followed by medicated soaps (50%) in 15 patients and commercial fragrances and cosmetic creams in 14 (46.67 %) patients. The history of application of hair dyes was found in 10 (33%) patients, coconut oil in nine (30%) patients, and turmeric/gram flour in four (13%) patients. There is a paucity of studies on cosmetic contact sensitivity in melasma. In a study by Sarkar et al. also, mustard oil was found to be a common cosmetic applied by melasma with men. In a study conducted by Prabha et al. from Himachal Pradesh, India, in 67 patients of melasma, the leading topical agent was found to be medicated soaps (86%), followed by cosmetic creams and fairness products (74%) and hair colors (25%).
In the present study, among 30 melasma patients, a total of 16 (53%) patients were found to show positive reactions on patch and photopatch testing with Indian cosmetic and fragrance series. In comparison, in control group, only one (3.3%) subject showed positive reaction. The difference was statistically significant (P < 0.001).
Among 32 allergens tested, 15 allergens were found to elicit a positive reaction in our study. Thiomersol was the most common contact sensitizer eliciting positive reaction in six (38%) patients, followed by cetrimide, hexamine and sorbitan each in three patients (19%). Only 3 of the 16 patients showed positive reaction from their own cosmetics such as PPD, coconut oil, and mustard oil. Benzyl salicylate, triclosan, musk mix, rose oil, tween 20, BHA, isopropyl myristate and kathon cg each was found to elicit positive reactions in 7% patients. Although the most common topical application by the patients was mustard oil and henna (53% each), this did not correspond to the common contact sensitizers found in the patients of melasma in this study. In Prabha et al.’s study, 29 (43.2%) patients with melasma showed positive patch test results from cosmetic allergens. Cetrimide was the most common contact sensitizer eliciting positivity in 15 (52%) patients, followed by gallate mix in nine (31%) patients and thiomersal in seven (24%) patients. However, in contrast to our present study, none of the patients were photopatch tested.
Thiomersol, an organic mercury compound (mercury ethyl sodium salt), is used as a preservative in skin lightening cosmetic creams, ophthalmic and nasal drops, contact lens solutions, and vaccines. The reported thiomersal contact sensitivity in patients of cosmetic dermatoses or pigmented cosmetic dermatitis varies from 8% to 77%. In the study population, thiomersol was the most common contact sensitizer eliciting positive reaction in six (38%) patients of melasma. Even in the study of Prabha et al., contact sensitivity to thiomersol was seen in 24% patients. Hence, our findings were in concordance with the only other similar Indian study. The patients who were patch test positive with thiomersal were using various facial fairness creams and contact lens solutions. This could be potentially relevant as a large number of Indian patients with facial hyperpigmentation use over-the-counter products (fairness creams or beauty soaps) to improve their complexion. This may warrant caution regarding the use of over-the-counter fairness creams and fairness products, especially if their melasma is recalcitrant.
Contact sensitivity to cetrimide was found in about 18% patients of melasma in our study. Cetrimide is a quaternary ammonium preservative and often used as an antiseptic and major excipient in cosmetics. The excipients are fillers or diluents, which are inert substances that serve as solubilizers, emulsifiers, and lubricants in a medication or cosmetics. However, they can be responsible for allergic or irritant contact dermatitis when used in higher concentrations. The patients who showed positive patch testing with cetrimide gave the history of using various cold (moisturizing) creams, medicated soaps, and aftershave lotions. The contact sensitivity to cetrimide (52%) in melasma patients was also found in Prabha et al.’s study, though in a higher percentage.
Apart from cetrimide, hexamine and sorbitan were also found to be contact sensitizers in 18% patients each. SorbitanSesquioleate is used in a variety of products including skin care products, skin cleansing products, moisturizers, and eye makeup and other makeup, primarily as an emollient. It is added to formulas as a skin soother and moisturizer and is derived from sorbitol, a humectant and considered as a low hazard ingredient. Hexamine is a common filler that owes its activity to formaldehyde and inactivates bacterial endotoxin preservation in cosmetics/skin care products. The female patients who showed positive patch testing with sorbitan and hexamine gave the history of frequent usage of foundations and eye makeup.
Only one (3.3%) patient from the study population had positive reaction to PPD (a common ingredient in hair color dyes) but never had clinical contact dermatitis despite using hair dyes and henna application on frequent basis. This was in concordance with the study of Prabha et al., in which positive reaction to PPD was found in two (3%) patients out of 29 patients with positive patch tests. In the same patient, benzyl salicylate was found to be positive on patch testing. It is a salicylic acid benzyl ester present in various face washes and other cosmetic products as an additive or UV absorber. On eliciting history, patient had been using Garnier men face wash for a long time, but never had any clinical contact dermatitis. Perhaps, we need to support the postulation given by Beltrani et al. that predicting the precise allergen in suspected cosmetics is difficult in view of ubiquitous presence of these allergens in finished cosmetic products.
Also, triclosan, musk mix, rose oil, tween 20, BHA, isopropyl myristate, and kathon cg each was found to elicit positive reactions in one (7%) patient. Apparently, these are uncommon contact sensitizers present as antioxidants, fragrances, and additives in various cosmetic/skin care products such as deodrants, leave on conditioners and shampoos, as observed in Prabha et al.’s study also.
Two (7%) patients showed contact photoallergy pattern and another two (7%) patients showed both contact photoallergy and contact allergy pattern to UVA exposure in the present study. To the best of our knowledge, the present study is the only one study of photopatch testing in patients of melasma in the Indian setup. In an earlier study by Verallo-Rowell et al. in Philippines, the source used for photopatch testing was visible light (tungsten halogen lamp source). Besides, the Philippines authors used North American photopatch series, plant series, and fragrance series for patch testing. In the same study, 11 (55%) patients showed photopatch positivity with 29 photoallergens (11 in the North American photopatch series, 7 in the plant series, and 11 in the fragrance series) to visible light. The melasma patients in the Verallo-Rowell’s study were sun shy, generally were exposed to low intensity UVA, visible light (VL), and infrared light (IL) from indirect sun and indoor artificial lights. It has been proposed by authors that low-energy VL-PhTCD is in part responsible for melasma, a mild pigmentation that gradually develops over time and readily worsens upon direct sun exposure. Visible light generates oxidation reaction that produces reactive oxygen species and peroxidation of lipids at cell membranes. These effects may lead to a delayed tanning response, without necessarily an increase in the quantity of melanocytes. So, this could be a possible mechanism for development of pigmentation in melasma as a photocontact dermatitis to various cosmetic allergens according to the Verallo-Rowell study. In our study, we could not test with visible light due to lack of special facilities and we patch tested Indian cosmetic and fragrance series with UVA exposure. The difference in allergens patch tested and photopatch test source could probably explain the lower percentage of photoallergy seen in our melasma patients.
It was observed that there was discordance between the patch/photopatch test results from individual cosmetic ingredients and the finished cosmetic product when patch tested. Dogra et al. also made similar observation that ingredients of cosmetics showed more frequent sensitivity as compared to the cosmetics applied as such, perhaps because ingredients are present in much lower concentration levels in finished cosmetics products and hence perhaps unable to elicit sufficient reaction. Moreover, manufacturers usually do not enumerate many of the key ingredients on the package of cosmetic goods.
This can be supported by the fact given by Prabha et al.’s study that the repeated contact with low levels of cosmetic allergens (e.g., preservatives, fragrances, diluents present in cosmetics) produces a type IV cytolytic reaction characterized by vacuolar basal degeneration and melanin incontinence rather than a frank eczematous reaction.
However, there are a few shortcomings of our study. A small sample size was chosen, taking into consideration the short time frame within which the study had to be completed and the limitation of patch test kits due to fiscal constraints. Also, due to lack of special facilities, a visible light source for photopatch testing could not be used.
| Conclusion|| |
Pigmented cosmetic dermatitis and cosmetic contact sensitivity should be possibly considered in the etiologic factors of melasma, especially in melasma not associated with pregnancy or lactation or hormone therapy. Larger sample size studies should be conducted to further ascertain the contact sensitivity of cosmetic allergens in melasma We suggest to educate patients with melasma, especially who are recalcitrant to all standard therapies, to limit the usage of over-the-counter cosmetic products such as fairness creams, medicated soaps, and aftershave lotions and make a judicious selection of cosmetic products in their daily life.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]