Hair Dye Use Research Articles

Abstract B81: Hair product use and breast cancer risk by hormone receptor status in the Women's Circle of Health Study

Abstract Introduction: Over the last several decades, the concern of environmental exposures to certain carcinogens and mutagens found in hair products, particularly hair dyes, have been explored for evidence of an association with breast cancer risk, yielding equivocal results. However, little is known about this association among African American (AA) women, who are common users of these products. The objective of this study was to examine the prevalence and patterns of use of hair products in AA and European American (EA) women in the Women's Circle of Health Study (WCHS), and their associations with breast cancer risk, overall and by estrogen receptor (ER+, ER-) and triple negative (TN) status. Methods: Data collection for the WCHS, a case-control study of breast cancer in New York City and several counties in New Jersey, was conducted through in-person interviews, with anthropometric and body composition measurements taken, and review of pathology records. At study entry, participants were asked on use of hair dyes, chemical relaxers/straighteners and cholesterol- and/or placenta-containing conditioning creams. Chi-square tests were used to compare differences in hair product variables by case-control status among AAs and EAs. Race-stratified, age-adjusted and multivariable-adjusted unconditional logistic regression models controlling for age, race, education, family history of breast cancer, oral contraceptive use, and body mass index were used to estimate odds ratios (OR) and 95% confidence intervals (CI) for associations between hair product use and risk among 4,285 women with breast cancer and controls (AA, n=2,798 and EA, n=1,487). Results: Among controls, 30.23% of AAs and 57.76% of EAs regularly used hair dye. Compared to light hair dye shades (blonde, light brown) use of darker shades (dark brown, black) was associated with increased odds of breast cancer among AA women (OR 1.64, 95% CI: 1.19-2.27), although there did not appear to be a dose response association with frequency of use. There were no associations between hair dye use and breast cancer risk among EA women. Use of chemical relaxers was more common among AAs than EAs (87.13% vs. 4.62% of AA and EA controls, respectively). Compared to AA women who used chemical relaxers without lye, those using products with lye were at increased risk (OR 1.54, 95% CI: 1.22-1.94). Among EA women although use of relaxers was not very common, compared to never users, those using relaxers (OR 1.74, 95% CI: 1.11-2.74) and using lye-containing relaxers (OR 4.37, 95% CI: 1.65-11.88) were at increased risk. Regular hair dye use (OR 1.20, 95% CI: 1.03-1.39), use of darker hair dye shades (OR 1.37, 95% CI: 1.05-1.77), and use of relaxers that contain lye (OR 1.26, 95% CI: 1.03-1.55) were associated with increased risk of ER+ BC. Regularly using both hair dyes and relaxers was associated with increased risk of ER+ BC (OR 1.20, 95% CI: 1.00-1.44). Regular hair dye use was not associated with risk of ER- or TNBC. The use of deep conditioning creams that contain cholesterol or placenta was also more common among AAs than EAs (56.12% vs. 6.01% of controls, respectively). However, there were no associations between use of these products and breast cancer risk. Conclusions: These findings from a large case-control study of AA and EA women provide additional epidemiological data to support a relationship between the use of some hair products, namely hair dyes and chemical relaxers, and risk of breast cancer. As use of various hair products and other cosmetics continue to increase among women in the U.S., particularly those at increased risk of breast cancer, improved awareness of the potential effects of exposures to their chemical ingredients are needed. Citation Format: Adana A.M. Llanos, Anna Rabkin, Gary Zirpoli, Cathleen Y. Xing, Bo Qin, Brian D. Gonzalez, Chi-Chen Hong, Kitaw Demissie, Elisa V. Bandera, Christine B. Ambrosone. Hair product use and breast cancer risk by hormone receptor status in the Women's Circle of Health Study. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr B81.

Semi-permanent hair dyes degradation at W/WO3 photoanode under controlled current density assisted by visible light

AbstractThe indiscriminate use of hair dyes has attracted great deal of attention due to its toxicological and mutagenic aspects demonstrated by some of these substances. Thus, the effluent from beauty salons and domestic sewages if not properly treated can reach water treatment plants and water sources, enhancing human health and environmental protection concern. This work explores the application of photoelectrocatalytic process on Basic Brown 16 and Basic Blue 99 degradation as model of basic hair dyes pollutants. W/WO

Tolerance to a Hair Dye Product Containing 2-Methoxymethyl-P-Phenylenediamine in an Ethnically Diverse Population of P-Phenylenediamine-Allergic Individuals.

Allergic contact dermatitis after exposure to p-phenylenediamine (PPD)-containing hair dye products is a common and important clinical problem. Because there is a high rate of cross-elicitation of allergic contact dermatitis to other important hair dye products (such as p-toluene diamine and other aminophenol hair dyes) in PPD-allergic patients, safer alternative dyes with excellent hair coloring options are needed. This study aimed to study tolerance to Me-PPD in a PPD-allergic cohort. Twenty ethnically diverse volunteers with a history of contact dermatitis to hair dyes or other PPD-containing chemicals and positive patch test results to 1% PPD in petrolatum were recruited to study their immediate and delayed skin reactivity to PPD, vehicle control, and 2-methoxy-methyl-PPD (Me-PPD) using the allergy alert test (simulating hair dyeing conditions) on volar forearm skin. This test is a short-contact open patch test. The Me-PPD may offer a safer alternative for PPD-allergic patients with an absent or reduced elicitation response in the allergy alert test simulating hair dye use conditions. The absent or reduced response to Me-PPD diagnosed using the allergy alert test has been shown to help reduce the possibility of moderate to severe cross-elicitation reactions among consumers during hair dyeing.

Para-Phenylenediamine Hypersensitivity: A Report From Budapest, Hungary, 2007-2014.

para-Phenylenediamine (PPD) is a potent allergen with frequent exposure through use of hair dyes or henna tattoos. We wished to determine if prevalence of PPD sensitivity is changing through time as trends in its use change. A total of 3631 patients were patch tested consecutively with the environmental standard series between 2007 and 2014 to map the prevalence of PPD sensitivity and its distribution according to age, sex, and diagnosis. Two hundred nine patients (5.75%) were proven to be PPD sensitive. Most PPD-sensitive patients were approximately in their 60s in 2007, whereas in 2014, they were in their 20s and 30s. In 2014, 61.1% of the patients were younger than 35 years and 50% were younger than 25 years. Of 209 PPD-sensitive patients, 32.5% had present relevance related to hair dyeing and eyebrow or eyelash coloring procedures. All affected male patients were hairdressers. Adverse reaction to henna was detected in only 1 case after henna hair dye use. The 5.75% prevalence of PPD sensitization in our study was higher compared with that in the European data. It is alarming that PPD hypersensitivity occurred even among teenagers. This may be mainly explained by hair dyeing at an early age.

Application of natural plant pigment in hair dyes

With the development of living condition, more and more people tend to show unique personality, thus hair dyes as hair cosmetics are highly favored. By the year 2012, the global sales of hair dye had exceeded $15 billion, with a sustained growth at a rate of 8%-10% annually. However, the harm caused by long-term use of hair dyes has aroused widespread public concern, so people begin to seek non-toxic or low toxic natural plant hair dyes. The types of commonly used hair dyes and the corresponding dyeing mechanisms were summarized in this manuscript, and the representative natural botanic dyes were listed. Thereafter, their effective fractions, constituents and application status were described. In addition, the values of botanic hair dyes and their broad market prospect were discussed. Finally, the problems that exist in the research and development of plant hair dyes were issued. This review may help to provide thought for developing novel, green and ecological natural plant hair dyes.

ESCD invited speaker abstracts: Focus Sessions

The introduction of a methoxymethyl side chain into para-phenylenediamine (PPD) resulted in the development of a new hair dye molecule: 2-methoxymethyl-para-phenylenediamine (Me-PPD). Besides having excellent hair colouring properties, this PPD derivate has significantly lower skin-sensitizing properties than PPD and toluene-2,5-diamine. In a simulated hair dye model (i.e. open-use test), cross-reactivity to Me-PPD occurred in PPD-allergic individuals, but the number of cross-reactors was substantially lower than one would expect in an open-use test with a PPD-containing hair dye. Patch testing with Me-PPD has never been performed. The current study aimed to find the optimal patch-test concentration for detecting cross-reactivity to Me-PPD. PPD-allergic patients with a documented history of hair dye-related allergy, and different grades (+, ++, +++) of positive patch-test reactions to PPD, will be included in the study. Patch testing will be performed with Me-PPD 0.1%, 0.25%, 0.5%, 1.0% and 2.0% in petrolatum. In a simulated hair dye use model on the volar forearm, the reactivity to use concentrations of Me-PPD 2% and PPD 2% will be investigated. On the adjacent skin a similar open-use test with the same basic formula, but without Me-PPD or PPD, will be applied as a control. After 45min the hair dye will be removed from the skin surface by rinsing with water. Reading of the patch tests and the open-use tests will be performed at days 2, 3 and 7, according to the International Contact Dermatitis Research Group reading criteria. In total 30 PPD-allergic individuals will be included in this Me-PPD dose-finding pilot study. At the moment a number of individuals have been enrolled; full data will be available at the meeting.

Assessing cortisol from hair samples in a large observational cohort: The Whitehall II study

Hair cortisol concentrations (HCC) have been suggested to reflect long-term integrated cortisol levels, but most evidence of associations with co-variates is from small samples of healthy volunteers.The objective of this study was to describe the collection of hair samples in a large cohort study and report associations of demographic and health measures with HCC. We examined HCC measured from the 3cm hair segment near the scalp in 3507 participants (aged 59–83y) from The Whitehall II occupational cohort study of British civil servants. Hair samples were analysed using a column switching LC–APCI–MS/MS assay. Findings from mutually adjusted linear regression analyses revealed lower HCC in participants who reported use of hair dye [% difference (95%CI); −12.5 (−22.0, −1.9), p value=0.022] and evidence suggestive of differences by length of sample storage and seasonal variation. With regard to demographic variables, HCC was lower in women compared to men [−17.0 (−24.8, −8.4), p value <0.001] and higher in Black compared to other ethnic groups. Prevalent diabetes, use of systemic corticosteroids and cardiovascular medication were independently associated with higher HCC. With regard to health, depressive symptoms were associated with higher HCC [20.0 (8.1, 33.3), p value=0.001] following adjustment for physical disease and medication. We conclude that hair steroid analysis presents significant opportunities for assessing cortisol in large scale cohorts. Demographic factors, sample storage, season of collection and hair characteristics should be considered in future analyses. Health status, both mental and physical, is linked to HCC.

A systematic review of the risk factors associated with the onset and progression of primary brain tumours

The overall aim of this systematic review was to identify risk factors for onset and natural progression, which were shown to increase, decrease, or have a null association with risk of primary brain tumour. For onset, the project was separated into two phases. The first phase consisted of a systematic search of existing systematic reviews and meta-analyses. Moderate to high methodological quality reviews were incorporated and summarized with relevant observational studies published since 2010, identified from a systematic search performed in phase 2. For natural progression, only the first phase was conducted. Standard systematic review methodology was utilized. Based on this review, various genetic variants, pesticide exposures, occupational farming/hairdressing, cured meat consumption and personal hair dye use appear to be associated with increased risk of onset amongst adults. The specific EGF polymorphsm 61-A allele within Caucasian populations and having a history of allergy was associated with a decreased risk. For progression, M1B-1 antigen was shown to increase the risk. High birth weight, pesticide exposure (childhood exposure, and parental occupational exposure) and maternal consumption of cured meat during pregnancy may also increase the risk of onset of childhood brain tumours. Conversely, maternal intake of pre-natal supplements (folic acid) appeared to decrease risk. Children with neurofibromatosis 2 were considered to have worse overall and relapse free survival compared to neurofibromatosis 1, as were those children who had grade III tumours compared to lesser grades.

A STUDY ON BRAND PREFERNCE OF CONSUMERS IN PURCHASING HAIR DYE IN TIRUNELVELI CITY

Hair dye use is very common among both Men &amp; Women. Hair dye users are increasing day by day coloring of hair is performed not only by professionals but also a popular cosmetic product. Hair dye is used mostly to change gray hair, since gray hair is a sign of an advanced age. Most of them are using hair dye in our home. Earlier natural hair dyes were used but now due to advancement in cosmetic industry, different types have been developed. There has been concern about hair dye since scientist is trying to find out if there is a link between hair color and cancer.

Hair dye use, regular exercise, and the risk and prognosis of prostate cancer: multicenter case-control and case-only studies.

BackgroundThis study investigated the effects that hair dye use and regular exercise exert on the risk and prognosis of prostate cancer.MethodsWe studied 296 cases of histologically confirmed prostate cancer and 296 age- (in 2-y bands), ethnicity-, and hospital-matched controls in Taiwan between August 2000 and December 2008. To determine the rate of prostate cancer survival, another 608 incident prostate cancer cases occurring between August 2000 and December 2007 were investigated. Information on hair dye use and regular exercise was obtained using a standardized questionnaire.ResultsThe use of hair dyes was associated with a significant 2.15-fold odds of developing prostate cancer (adjusted odds ratio = 2.15, 95 % confidence interval [CI] = 1.32–3.57), but was not associated with prostate cancer survival, compared with no use. The significant risks were more prominent in users aged < 60 years who had used hair dyes for > 10 years, > 6 times per year, and started using hair dyes before 1980. By contrast, regular exercise significantly reduced the number of prostate-cancer-specific death (adjusted hazard ratio = 0.37, 95 % CI = 0.16–0.83); the protective effect of exercise was more prominent among cancer patients who exercised daily (≥7 times/week). However, exercise could not prevent the development of prostate cancer.ConclusionsHair dye use increased the risk of prostate cancer, whereas regular exercise reduced the number of prostate-cancer-specific deaths.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2280-7) contains supplementary material, which is available to authorized users.

Morbidity and Mortality in 7,684 Women According to Personal Hair Dye Use: The Copenhagen City Heart Study followed for 37 Years.

BackgroundPermanent hair dye contains aromatic amines which are carcinogenic, and can cause allergic skin reactions. In the long term personal use of hair dye might therefore influence both morbidity and mortality.ObjectivesWe tested the hypothesis that personal use of hair dye in women is associated with increased morbidity and mortality in the general population.MethodsWe included 7,684 women from the Copenhagen City Heart Study with information on the use of personal hair dye. We assessed the risk of cancer, skin diseases, other morbidities, and mortality during a median follow-up of 27 years (range 0–37).ResultsThe multivariable adjusted hazard ratio for malignant melanoma in women with versus without personal use of hair dye was 2.07 (95% confidence interval 1.25–3.42). There was no increased risk of other cancer types. For other skin diseases and other major causes of morbidity we found no differences between the two groups, except for a minor excess of digestive diseases and increased risk of Parkinson’s disease among women using hair dye. Finally, we found no difference in all-cause mortality comparing women using personal hair dye or not. After correction for multiple comparisons, none of the results remained significant. However, in sensitivity analysis the excess risk of malignant melanoma remained increased with a hazard ratio of 2.58 (95%CI 1.33–5.03) among users of personal hair dye.ConclusionsPersonal use of hair dye does not have major influences on morbidity and mortality. Our finding of a 2-fold risk of malignant melanoma in women using hair dye is hypothesis generating.

Prevalence of Contact Allergy to p-Phenylenediamine in the European General Population

Population-based studies on contact allergy to p-phenylenediamine (PPD) are scarce. A cross-sectional study was performed to assess the prevalence of contact allergy to PPD and its risk factors in the general population of 5 European countries. A total of 10,425 subjects were interviewed, and a random sample (n = 2,739) was patch tested to PPD. Overall, 5,286 individuals (50.9%) reported having used hair colorants at least once in their lifetime (78% female, 20% male), and 35% had used hair colorants during the last 12 months. Hair colorant avoidance because of any skin problem during the lifetime was reported by 6%. Black henna tattoos had been used by 5.5% during their lifetime. The prevalence of PPD contact allergy was 0.8% (95% confidence interval 0.6-1.0%), with no statistically significant association with gender or hair dye use. The prevalence of PPD in black henna tattoo users was 3.2% versus 0.6% in nonusers (P < 0.001). A clinically relevant positive patch test reaction to PPD related to hair coloring products was found in 0.1% (95% confidence interval 0.0-0.2%). A significant association with PPD contact allergy was observed for subjects who had black henna tattoos in their lifetime, with an age- and gender-adjusted odds ratio of 9.33 (95% confidence interval 3.45-25.26, P < 0.001). Black henna tattoos are an important risk factor for PPD contact allergy.

Lifestyle factors and risk of leukemia and non-Hodgkin's lymphoma: a case-control study.

Risk factors for leukemia and lymphomas in adults are largely unknown. This study was aimed at evaluating the association between lifestyle factors and the risk of hematological malignancies in an adult population. Data were drawn from a population-based case-control study carried out in Italy and included 294 cases (199 lymphoid and 95 myeloid) and 279 controls. Analyses were performed using standard multivariable logistic regression. Hair dye use for at least 15 years was associated with a higher risk of lymphoid malignancies among females (OR 2.3, 95 % CI 1.0-4.9, p = 0.036, test for trend). Furthermore, a protective effect of a moderate to heavy tea consumption on the risk of myeloid malignancies was observed (OR 0.4, 95 % CI 0.2-0.9, p = 0.017). No association was found for the use of alcoholic beverages and tobacco smoking. Our results confirm the potential carcinogenic effect of prolonged hair dye use observed in previous investigations. The excess risk could be explained by exposure to a higher concentration of toxic compounds in hair products used in the past. The protective effect of regular tea consumption observed in an area with a very high prevalence of black tea consumers deserves further investigation.

Hair cortisol and self-reported stress in healthy, working adults

Chronic stress can be important in the pathology of chronic disease. Hair cortisol concentrations (HCC) are proposed to reflect long term cortisol secretion from exposure to stress. To date, inconsistencies in the relationship between HCC and self-reported stress have been attributed to variation and limitations of perceived stress measurement. We report data from employees of two large public sector worksites (n=132). Socio-demographic, health, lifestyle, perceived stress scale (PSS), and work-related effort reward imbalance (ERI) were collected at baseline. Participants were asked to respond to mobile text messages every two days, asking them to report current stress levels (Ecological momentary assessment, EMA), and mean stress was determined overall, during work hours, and out of work hours. At 12 weeks, the appraisal of stressful life events scale (ALES) was completed and 3cm scalp hair samples were taken, from which HCC was determined (to reflect cortisol secretion over the past 12 weeks). Mean response rate to EMA was 81.9±14.9%. Associations between HCC and the various self-reported stress measures (adjusted for use of hair dye) were weak (all<.3). We observed significant associations with HCC for EMA measured stress responses received out of work hours (ρ=.196, p=.013) and ALES Loss subscale (ρ=.241, p=.003), and two individual items from ERI (relating to future work situation). In regression analysis adjusting for other possible confounders, only the HCC-ALES Loss association remained significant (p=.011). Overall, our study confirms that EMA provides a useful measurement tool that can gather perceived stress measures in real-time. But, there was no relationship between self-reported stress collected in this way, and HCC. The modest association between HCC and stress appraisal does however, provide some evidence for the role of cognitive processes in chronic stress.

Does Hair Dye Use Increase the Risk of Breast Cancer? A Population-Based Case-Control Study of Finnish Women.

IntroductionRole of hair dyes in the etiology of breast cancer has occasionally raised concern but previous research has concluded with mixed results. Remnants of prohibited aromatic amines have been found in many hair dye products, and elevated levels of DNA-adducts of these amines have been detected from breast epithelial cells of hair dye users. However, the IARC working group has concluded that there is inadequate evidence for carcinogenicity of personal hair dye use and limited evidence in experimental animals for carcinogenicity of hair colorants.Material and MethodsWe investigated whether the use of hair dyes is associated with breast cancer risk in women. The study design was a retrospective population-based case-control study in Finland, with a self-administered questionnaire from 6,567 breast cancer patients, aged 22–60 years and diagnosed in 2000–2007, and their 21,598 matched controls. We report odds ratios (OR) with 95% confidence interval (95% CI) from a conditional logistic regression model applied to the frequency matched sets of cases and controls. Bias-adjusted odds ratios from the sensitivity analysis are also presented.ResultsAfter adjusting for potential confounders, the odds of breast cancer increased by 23% (OR: 1.23, 95% CI: 1.11–1.36) among women who used hair dyes compared to those who did not. In women born before 1950 an increase of 28% was noted (OR: 1.28, 95% CI: 1.10–1.48). We also observed a significant trend between the OR and cumulative use of hair dyes (P: 0.005). Bias-adjusted odds ratios varied between 1.04 and 2.50.ConclusionsOur results suggest that use of hair dyes is associated with breast cancer incidence. The impact on public health may be substantial due to vast popularity of hair coloring in modern societies. It should be noted that regardless of all efforts, a possibility of bias cannot definitively be ruled out and use of a prospective design is warranted. Based on the present results, it may be concluded however that safety of hair dyes in relation to breast cancer cannot yet be fully acknowledged and lack of external safety assessment within the cosmetics industry is of major concern.

Association of hair dye use with circulating levels of sex hormones in premenopausal Japanese women.

Substances identified as animal carcinogens are no longer used as ingredients of hair dyes. However, hair dyes are diverse groups of chemicals, and certain compounds may affect endogenous sex hormone levels. We examined the association between hair dye use and sex hormone levels among premenopausal women. Study subjects were 431 premenopausal Japanese women who had regular menstrual cycles less than 40 days long. Information on the use of hair dyes or hair bleach, the type of hair coloring used, the duration of use and the frequency of application was collected using a self-administered questionnaire. Fasting plasma samples were obtained to measure estradiol, testosterone, dehydroepiandrosterone sulfate, sex hormone-binding globulin, follicle-stimulating hormone and luteinizing hormone. After controlling for covariates, the mean plasma total testosterone level was about 14% higher in women who had used hair dyes for 10 or more years than that among women who had never used them (P for trend = 0.02). A similar association was observed when the type of hair dye was restricted to permanent hair dyes. A higher frequency of applying non-permanent hair dyes was marginally significantly associated with higher total and free estradiol levels. Data suggest that long-term use of hair dyes may be associated with an increase in circulating testosterone levels. As this is, to our knowledge, the first study examining the association between hair dye use and sex hormone levels, replication of the results is required.

Hair dye: A trichoscopy pitfall

Hair and scalp disorders account for a large proportion of the presenting complaints to dermatologists. Trichoscopy (dermoscopy of the hair and scalp) serves as a very important diagnostic tool.1 However, evaluation of the hair and scalp may be additionally challenging if the patient has a history of hair dye use. Permanent and semipermanent hair dyes can mimic distinct pathologies. Permanent hair dye may penetrate hair follicles, giving a “black dot” appearance that is characteristic of active alopecia areata (Fig 1).

Cross-elicitation responses to 2-methoxymethyl-p-phenylenediamine under hair dye use conditions in p-phenylenediamine-allergic individuals.

The factors influencing elicitation responses in individuals allergic to p-phenylenediamine (PPD) in hair dyes are not well understood. Investigation of the elicitation response to the new, less-sensitizing PPD alternative 2-methoxymethyl-p-phenylenediamine (ME-PPD) under simulated hair dye use conditions. The cross-elicitation response to ME-PPD (2% in a hair dye test product for 30 min on forearm then rinsing) was analysed at days 2 and 3 in 30 PPD-allergic individuals with diagnostic patch test grades +, ++ or +++ according to the classification of the International Contact Dermatitis Research Group. Cross-reactivity to the ME-PPD-containing hair dye test product was elicited in nine of 30 subjects (30%), while 70% were negative. Cross-reactivity was elicited in two of four cases with grade +++, three of 10 with grade ++ and four of 16 with grade +. Under identical conditions, PPD was previously found to elicit a response in 21 of 27 PPD-allergic individuals. In 18 of these 21 individuals, either the strength of the cross-elicitation response to ME-PPD was decreased or no response occurred. Under simulated hair dye use conditions, a significantly lower degree of cross-elicitation to ME-PPD (30%) was observed than previously reported for PPD (32 of 38, 84%). Additionally, a decreased cross-elicitation strength was observed across all three patch test grades, likely reflecting the reduced skin-sensitization properties of ME-PPD. Consequently, careful dermatological evaluation is required to assess cross-reactivity to ME-PPD in patients allergic to hair dyes.

Contact allergy trends in Sweden - a retrospective comparison of patch test data from 1992, 2000, and 2009.

Contact allergy prevalence rates change over time as a result of variations in allergen exposure. Data from patch test clinics are often used as markers for allergy trends. The aim of the present retrospective study was to describe trends in rates of sensitization to allergens in the Swedish baseline series. Prevalence rates are described by comparing consecutive patch test data from 1992, 2000 and 2009 in Swedish patch test clinics. In total, 3680 patients were included in 1992, 3825 in 2000, and 3112 in 2009. Among test substances with a sensitization rate above 2% in 2009, significant decreases were noted for nickel sulfate, cobalt chloride, colophonium, and methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI), and a significant increase for p-phenylenediamine, as compared with 1992. Potassium dichromate reactions had increased among younger women, whereas reactions to nickel and cobalt had decreased in this group. Sensitization to chromium, cobalt and fragrance mix I had decreased among older men, and sensitization to nickel had decreased among younger men. It is probable that these changes in 1992-2009 reflect both changes in regulations for nickel, lower levels of chromium in cement and of MCI/MI in cosmetics, and increasing use of hair dyes.

Hair dyes resorcinol and lawsone reduce production of melanin in melanoma cells by tyrosinase activity inhibition and decreasing tyrosinase and microphthalmia-associated transcription factor (MITF) expression.

Hair coloring products are one of the most important cosmetics for modern people; there are three major types of hair dyes, including the temporary, semi-permanent and permanent hair dyes. The selected hair dyes (such as ammonium persulfate, sodium persulfate, resorcinol and lawsone) are the important components for hair coloring products. Therefore, we analyzed the effects of these compounds on melanogenesis in B16-F10 melanoma cells. The results proved that hair dyes resorcinol and lawsone can reduce the production of melanin. The results also confirmed that resorcinol and lawsone inhibit mushroom and cellular tyrosinase activities in vitro. Resorcinol and lawsone can also downregulate the protein levels of tyrosinase and microphthalmia-associated transcription factor (MITF) in B16-F10 cells. Thus, we suggest that frequent use of hair dyes may have the risk of reducing natural melanin production in hair follicles. Moreover, resorcinol and lawsone may also be used as hypopigmenting agents to food, agricultural and cosmetic industry in the future.