Nickel release from inexpensive jewelry and hair clasps purchased in an EU country - Are consumers sufficiently protected from nickel exposure?

Self-reported Nickel Allergy among Schoolchildren: Trends in Prevalence, Risk Factors, and Atopic Comorbidity

Nickel allergy is common among children. The present study investigated prevalence trends of self-reported nickel allergy, risk factors, and atopic comorbidity among children. Eight-year-old children from Norrbotten County, Sweden, were recruited in 1996 (n = 3,430), 2006 (n = 2,585), and 2017 (n = 2,785). Self-reported nickel allergy decreased from 7.7% (2006) to 6.1% (2017; p = 0.024) and was significantly more common among girls. In 1996, only children with atopic dermatitis answered questions on nickel allergy. Among children with atopic dermatitis, no significant decrease was seen over the years 1996 to 2017. Ear piercing (odds ratio [OR] 1.93, 95% confidence interval [CI] 1.39-2.68 and OR 5.57, 95% CI 3.71-8.38) and female sex (OR 4.05, 95% CI 2.68-6.13 and OR 1.73, 95% CI 1.09-2.74) were risk factors for self-reported nickel allergy in 2006 and 2017, respectively. Self-reported nickel allergy was significantly more prevalent among children with atopic dermatitis than without in 2006 (12.3% vs 6.4%; p < 0.001) and 2017 (11.5% vs 5.1%; p < 0.001), and among children with allergic rhinitis in 2017 (8.6% vs 4.7%; p = 0.015). In conclusion, we found a decreasing prevalence of self-reported nickel allergy, but not among children with atopic dermatitis. Ear piercing and female sex were strongly associated with nickel allergy. Our findings also suggest that nickel allergy is associated with atopic dermatitis and allergic rhinitis.

Allergic contact dermatitis of the scalp: a review of an underdiagnosed entity

Background

It is hypothesized that scalp allergic contact dermatitis (ACD) in women is commonly mistaken for other disorders due to overlapping symptoms and unique clinical presentations.

Objective

This study reviews the potential underdiagnosis and misdiagnosis of scalp ACD and explores ways to improve diagnostic accuracy.

Methods

This study conducted an extensive literature review to identify diagnostic challenges, common misdiagnoses, and diagnostic approaches for scalp ACD, focusing on standard versus targeted patch testing techniques.

Results

Scalp ACD, often misdiagnosed as seborrheic dermatitis due to similar symptoms, has atypical presentations such as hair thinning, hair loss, and erythematous lesions affecting neighboring regions. Trichoscopy can help distinguish scalp ACD, identifying its patchy distribution of thin white scales, in contrast to the yellow scaling of seborrheic dermatitis. Standardized patch testing further contributes to diagnostic errors, with a study reporting 83% of patients who tested negative with standardized patch tests were positive when using their personal products. Individualized patch testing is more effective in identifying causative allergens and accurately diagnosing scalp ACD.

Limitations

It is a retrospective review.

Conclusion

Several factors contribute to scalp ACD's misdiagnosis for conditions such as seborrheic dermatitis. The significant discrepancy in ACD detection rates between personalized and standardized patch tests in women emphasizes the importance of using patient-specific products in diagnostic testing. Incorporating scalp ACD more readily into one's differential, employing individualized patch testing with trichoscopy, and accounting for neighboring symptomatic areas are all crucial elements in improving diagnostic accuracy for scalp ACD in women.

Adverse Food Reactions in Inflammatory Bowel Disease: State of the Art and Future Perspectives

Limited knowledge is available about the relationship between food allergies or intolerances and inflammatory bowel disease (IBD). Clinicians frequently encounter patients who report food allergies or intolerances, and gastroenterologists struggle distinguishing between patients with organic disorders and those with functional disorders, which the patients themselves may associate with specific dietary components. This task becomes even more arduous when managing patients with significant underlying organic conditions, like IBD. The aim of this review is to summarize and emphasize any actual associations between food allergies and intolerances and inflammatory diseases, such as ulcerative colitis and Crohn's disease. Through a narrative disceptation of the current literature, we highlight the increased prevalence of various food intolerances, including lactose, fructose, histamine, nickel, and non-celiac gluten sensitivity, in individuals with IBD. Additionally, we explore the association between increased epithelial barrier permeability in IBD and the development of food sensitization. By doing so, we aim to enhance clinicians' awareness of the nutritional management of patients with IBD when facing complaints or evidence of food allergies or intolerances.

An investigation into the present levels of contamination in children's toys and jewelry in different countries: a systematic review

Contamination by heavy metals and toxic elements in children's toys and jewelry is an ongoing challenge in different countries. These contaminants can enter the children's body via oral, dermal, and respiratory routes, leading to adverse health effects. This study aimed to investigate the present levels of contamination in children's toys and jewelry in 15 countries, including UK, Saudi Arabia, Cambodia, China, Kosovo, Nigeria, North American, Kazakhstan, UAE, Pakistan, Iraq, Israel, West Bank/Palestine, Czech Republic, and Turkey. In this review, the legislation and recommendation of the United States (U.S.), the Bureau of Indian Standards (BIS), Turkish Standards Institute (TSE), Canada, and the European Union (E.U.) on toxic elements in toys and jewelry are introduced. Plastic or metallic toys and children's jewelry still have the most severe toxic elements pollution and the existence of lead (Pb), nickel (Ni), cadmium (Cd), arsenic (As), mercury (Hg), chromium (Cr), copper (Cu), selenium (Se), barium (Ba), Zinc (Zn), cobalt (Co), manganese (Mn), bisphenol A, phthalates, parabens, azo dyes, and flame retardants has been regarded as an ongoing challenge in these articles. Finally, this review offers benchmarking of the concentrations of toxic elements in all types of children's toys and jewelry in different nations.

Allergic Contact Dermatitis of the Scalp Associated With Scalp Applied Products: A Systematic Review of Topical Allergens

ABSTRACT

Hair products are commonly used to maintain hair health or cosmesis. Products applied to the scalp and hair contain multiple active and inactive ingredients that can potentially cause irritant and/or allergic contact dermatitis. The objectives of this study were to identify and to discuss the most common allergens in scalp and hair applied products causing scalp allergic contact dermatitis (ACD). A PubMed search identified 99 studies, with 3185 patients and 31 categories of scalp products. Hair products reportedly associated with scalp ACD were hair dyes (41%), shampoos (28%), and conditioners (22%). The most commonly reported patch test-positive allergens were p-phenylenediamine (23%), nickel (15%), fragrance mix (13%), balsam of Peru (10%), cocamidopropyl betaine/3-dimethylaminopropylamine (7%), and methylchloroisothiazolinone/methylisothiazolinone (6%). Common symptoms and signs include eczematous lesions, pruritus, and a burning sensation. Medical practitioners should be aware of causative agents to provide appropriate patient education, counseling, and/or treatment.

Nickel and cobalt release from beauty tools: a field study in the German cosmetics trade

BACKGROUND

Relevant nickel and cobalt release from hairdressing tools has recently been evidenced. Comparable data are not available for tools used in beauty salons.

OBJECTIVES

Screening of beauty tools for nickel and cobalt release.

METHODS/MATERIALS

Three hundred eight beauty tools were tested in seven beauty salons located in two North-German states. A nickel spot test and a cobalt spot test were used to test the tools for nickel release and cobalt release, respectively.

RESULTS

143 of 308 beauty tools overall (46.4%; 95%CI: 40.8-52.2%) released nickel and 18 of 308 beauty tools overall (5.8%; 95%CI: 3.5-9.1%) released cobalt. Nickel release was found in 22 of 99 metal tools (22.2%; 95%CI: 14.5-31.7%) and 121 of 209 tools with metallic parts (57.9%; 95%CI: 50.9-64.7%); cobalt release was detected in 3 of 99 metal tools (3.0%; 95%CI: 0.63-8.6%) and 15 of 209 tools with metallic parts (7.2%; 95%CI: 4.1-11.6%).

CONCLUSIONS

Nickel and cobalt are emitted at allergologically relevant levels by a wide range of beauty tools (i.e., metal tools and tools with metallic parts) utilized in the German cosmetics trade. Beauty tools should thus be considered occupational sources of nickel and cobalt exposure. This article is protected by copyright. All rights reserved.

Climate Effect, Globalization, and Ethics in Allergy

The prevalence of allergic diseases is increasing rapidly and has already reached an epidemic level. Two major drivers of this development are climate change and globalization, which both induce an increase in allergens. Concomitant climate change fosters the spreading of the latter on a global scale. The increase in allergens not only aggravates the symptoms and the degree of suffering for patients who already are allergic, but also gives rise to new cases of allergies. The distribution of allergies in society follows a steep socioeconomic gradient worldwide. According to well-established theories of justice such a distribution of the allergy burden is unfair. This fact adds a major ethical dimension and challenge to the allergy epidemic. This chapter draws on the key points of policies for allergy prevention and treatment. It shows how related programs and measures can be conceptualized and prioritized according to the principles of distributional justice.

Nickel release from metallic earrings: A survey of the Danish market and validation of the nickel spot test

BACKGROUND

Exposure to nickel-releasing ear-piercing jewellery may explain the persistently high prevalence of nickel allergy in Europe. While nickel release from earrings is regulated, field studies show that the regulation is not always respected. More knowledge is needed regarding the risk of piercing exposure including suitable screening methods.

OBJECTIVE

To examine the proportion of earrings on the Danish market that release more nickel than allowed, and to validate the use of the dimethylglyoxime (DMG) test as a screening tool.

METHODS

A total of 304 earrings were purchased and tested with the DMG test and X-ray fluorescence spectrometry. The level of nickel release was quantified in a selected subsample of 100 earrings by the European reference test EN 1811. The DMG spot test was validated against EN 1811 at different thresholds.

RESULTS

Excessive nickel release according to the European regulation was found in 45 (14.8%) tested earrings. The sensitivity of the DMG test decreased with reduced levels of nickel release (sensitivity of 45.2% at ≥0.2 μg/cm2 /week vs 61.1% at >0.5 μg/cm2 /week).

CONCLUSION

Excessive nickel release is common in earrings on the Danish market. Because of low sensitivity, the DMG test has limited use in screening of earrings for research but may still be used clinically.

Experimental evaluation of nickel and cobalt release from tools and self-reported prevalence of nickel and cobalt allergy in the German hairdressing trade

BACKGROUND

Nickel release from some metal tools in the hairdressing trade has been sporadically evidenced, whereas data about cobalt release from metal tools in the hairdressing trade are lacking.

OBJECTIVES

To screen metal tools for nickel and cobalt release and to estimate the prevalence of nickel allergy and cobalt allergy in the German hairdressing trade.

METHODS

Four hundred seventy-five metal tools in the hairdressing trade were tested in three North German states with a nickel spot test for nickel release and with a cobalt spot test for cobalt release. Seventy hairdressers were surveyed with a standardized questionnaire to collect data about the tested metal tools as well as the prevalence of nickel allergy and cobalt allergy.

RESULTS

One hundred thirty-one of 475 metal tools (27.6%) - 60 of 60 hair clips (100%), five of five crochet hooks (100%), 24 of 40 tweezers (60.0%), 33 of 75 sectioning clips (44.0%), five of 32 straight razors (15.6%), and four of 45 tail combs (8.9%) - released nickel and 10 of 475 metal tools (2.1%) - three of 40 tweezers (7.5%), four of 60 hair clips (6.7%), one of 32 straight razors (3.1%), and two of 75 sectioning clips (2.7%) - released cobalt. Eight of 63 female hairdressers (12.7%) suffered from nickel allergy and two of 63 female hairdressers (3.2%) suffered from cobalt allergy.

CONCLUSIONS

Metal tools in the German hairdressing trade - with which a prolonged skin contact is intended - release nickel and cobalt in allergologically relevant amounts and thus should be taken into account as occupational sources of exposure to nickel and cobalt.

A Comprehensive Artificial Sweat Study for Quantitation of Nickel and Other Inorganic Elements Released from Imitation Earrings Purchased in Istanbul Market

Element sensitization is frequent cause of allergic contact dermatitis, and Ni is the main reason for this condition owing to daily use of different Ni-containing items. European Union established a limit of 0.2 μg/cm²/week Ni release for the items by the Ni Directive in 2004. The aim of this study was to determine the amount of element release of imitation earrings sold in different points of Istanbul with different prices and consider the element release levels including 29 trace and toxic elements. After calculation of released nickel amounts, 31.80% of earrings (71 of 223) were observed over the limit of European Commission Directive's migration limit. Minimum and maximum nickel release amounts were found as 0.21 and 30.11 μg/cm²/week, respectively, and mean level was found 3.24 μg/cm²/week among 71 positive earrings. Results showed that essential part of imitation earrings used especially by women release nickel particles over the European Commission Directive's migration limit. In addition, other elements such as Cu, Cr, and Co were found to be in the structure of the imitation earrings, as well as high amounts of toxic element Pb.

Nickel chelation therapy as an approach to combat multi-drug resistant enteric pathogens

The nickel (Ni)-specific chelator dimethylglyoxime (DMG) has been used for many years to detect, quantitate or decrease Ni levels in various environments. Addition of DMG at millimolar levels has a bacteriostatic effect on some enteric pathogens, including multidrug resistant (MDR) strains of Salmonella Typhimurium and Klebsiella pneumoniae. DMG inhibited activity of two Ni-containing enzymes, Salmonella hydrogenase and Klebsiella urease. Oral delivery of nontoxic levels of DMG to mice previously inoculated with S. Typhimurium led to a 50% survival rate, while 100% of infected mice in the no-DMG control group succumbed to salmonellosis. Pathogen colonization numbers from livers and spleens of mice were 10- fold reduced by DMG treatment of the Salmonella-infected mice. Using Nuclear Magnetic Resonance, we were able to detect DMG in the livers of DMG-(orally) treated mice. Inoculation of Galleria mellonella (wax moth) larvae with DMG prior to injection of either MDR K. pneumoniae or MDR S. Typhimurium led to 40% and 60% survival, respectively, compared to 100% mortality of larvae infected with either pathogen, but without prior DMG administration. Our results suggest that DMG-mediated Ni-chelation could provide a novel approach to combat enteric pathogens, including recalcitrant multi-drug resistant strains.

Nickel dermatitis from earrings 15 years after EU directive implementation: a clinical-epidemiological study and a market survey in Rome, Italy

BACKGROUND

Nickel (Ni) dermatitis remains a highly prevalent allergic condition in Italy. There is a continuous need for clinical and epidemiological surveillance to evaluate whether or not European Ni Directive has been effective in contact allergy prevention.

OBJECTIVES

To assess the prevalence of Ni dermatitis among patch-tested patients and self-interviewed school students and to analyse Ni release from earlobe jewellery.

METHODS

Results of patch tests performed in 2006-2007, 2015-2016 and 2017-2018 were retrieved. A questionnaire was compiled by 315 secondary school students. Ni release from earring parts was analysed with the EN1811:2015 method.

RESULTS

A significant time trend of decreasing Ni positivity from 2006-2007 to 2017-2018 was observed both in the overall population (44.1% in 2006-2007, 33.0% in 2015-2016, 31.6% in 2017-2018, P < 0.0001) and in female patients (P < 0.0001). Conversely, change was not significant in males (P = 0.16). Decrease was significant for all age groups, except for those aged >60 years (P = 0.51). Among 242 students who reported earring use, 130 (54%) reported symptoms at earlobes, mostly associated with jewellery of materials other than gold and silver (59% of those with earlobe symptoms). Ni release exceeded the migration limit in 4/21 (20%) earring parts.

CONCLUSIONS

A high prevalence of Ni dermatitis and earlobe symptoms were found in Rome. A decreasing time trend was noted, with a significant decline in Ni sensitivity compared to the situation observed right after Ni Directive implementation. This most likely represents the consequence of reduced Ni content in earring parts, although a major care in the use of Ni-containing objects could contribute to explain these findings.

Nickel release from metal tools in the German hairdressing trade-A current analysis

BACKGROUND

Nickel is one of the most common contact allergens. Despite EU regulations concerning the maximum permissible release of nickel from metal objects, nickel release at inappropriately high levels from metal objects has been detected in various studies.

OBJECTIVES

To screen current nickel release from metal tools in the German hairdressing trade.

METHODS

Two hundred and twenty-nine metal tools from the German hairdressing trade were tested with the dimethylglyoxime (DMG) test for nickel release. Additionally, an employee survey was conducted to collect data about the metal tools.

RESULTS

The DMG test showed that 21 of 229 metal tools (9.2%) released nickel. Nickel release was detected in 8 of 45 hair clips (17.8%), 2 of 27 tail combs (7.4%), and 11 of 17 tweezers (64.7%).

CONCLUSION

It must be assumed that hairdressers in Germany have prolonged skin contact with nickel-releasing metal tools. This should prompt further testing for nickel release from metal tools, and the development of regulations to eliminate nickel-releasing metal tools in the (German) hairdressing trade.

Biokinetics of Nanomaterials: the Role of Biopersistence

Nanotechnology risk management strategies and environmental regulations continue to rely on hazard and exposure assessment protocols developed for bulk materials, including larger size particles, while commercial application of nanomaterials (NMs) increases. In order to support and corroborate risk assessment of NMs for workers, consumers, and the environment it is crucial to establish the impact of biopersistence of NMs at realistic doses. In the future, such data will allow a more refined future categorization of NMs. Despite many experiments on NM characterization and numerous in vitro and in vivo studies, several questions remain unanswered including the influence of biopersistence on the toxicity of NMs. It is unclear which criteria to apply to characterize a NM as biopersistent. Detection and quantification of NMs, especially determination of their state, i.e., dissolution, aggregation, and agglomeration within biological matrices and other environments are still challenging tasks; moreover mechanisms of nanoparticle (NP) translocation and persistence remain critical gaps. This review summarizes the current understanding of NM biokinetics focusing on determinants of biopersistence. Thorough particle characterization in different exposure scenarios and biological matrices requires use of suitable analytical methods and is a prerequisite to understand biopersistence and for the development of appropriate dosimetry. Analytical tools that potentially can facilitate elucidation of key NM characteristics, such as ion beam microscopy (IBM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), are discussed in relation to their potential to advance the understanding of biopersistent NM kinetics. We conclude that a major requirement for future nanosafety research is the development and application of analytical tools to characterize NPs in different exposure scenarios and biological matrices.

Common Allergens Identified Based on Patch Test Results in Patients with Suspected Contact Dermatitis of the Scalp

BACKGROUND

Contact dermatitis of the scalp is common and might be caused by many chemicals including metals, ingredients of shampoos and conditioners, dyes, or other hair treatments. Eliciting a careful history and patch tests are necessary to identify the responsible allergen and prevent relapses.

OBJECTIVES

To identify allergens that may cause contact dermatitis of the scalp by reviewing patch test results.

METHODS

We reviewed the records of 1,015 patients referred for patch testing at the Dermatology Department of the University of Miami. A total of 226 patients (205 females and 21 males) with suspected scalp contact dermatitis were identified, and the patch test results and clinical data for those patients were analyzed. Most patients were referred for patch testing from a specialized hair clinic at our institution.

RESULTS

The most common allergens in our study population were nickel (23.8%), cobalt (21.0%), balsam of Peru (18.2%), fragrance mix (14.4%), carba mix (11.6%), and propylene glycol (PG) (8.8%). The majority of patients were females aged 40-59 years, and scalp itching or burning were reported as the most common symptom.

CONCLUSION

Frequent sources of allergens for metals include hair clasps, pins, and brushes, while frequent sources of allergens for preservatives, fragrance mix, and balsam of Peru include shampoos, conditioners, and hair gels. Frequent sources of allergens for PG include topical medications.

Nickel and cobalt release from jewellery and metal clothing items in Korea

BACKGROUND

In Korea, the prevalence of nickel allergy has shown a sharply increasing trend. Cobalt contact allergy is often associated with concomitant reactions to nickel, and is more common in Korea than in western countries.

OBJECTIVE

The aim of the present study was to investigate the prevalence of items that release nickel and cobalt on the Korean market.

MATERIALS AND METHODS

A total of 471 items that included 193 branded jewellery, 202 non-branded jewellery and 76 metal clothing items were sampled and studied with a dimethylglyoxime (DMG) test and a cobalt spot test to detect nickel and cobalt release, respectively.

RESULTS

Nickel release was detected in 47.8% of the tested items. The positive rates in the DMG test were 12.4% for the branded jewellery, 70.8% for the non-branded jewellery, and 76.3% for the metal clothing items. Cobalt release was found in 6.2% of items. Among the types of jewellery, belts and hair pins showed higher positive rates in both the DMG test and the cobalt spot test.

CONCLUSION

Our study shows that the prevalence of items that release nickel or cobalt among jewellery and metal clothing items is high in Korea.

Positive nickel patch tests in infants are of low clinical relevance and rarely reproducible

BACKGROUND

We have previously reported patch test reactivity to nickel sulphate in a cohort of unselected infants tested repeatedly at 3-18 months of age. A reproducible positive reaction at 12 and 18 months was selected as a sign of nickel sensitivity provided a patch test with an empty Finn chamber was negative. A reproducible positive reaction was seen in 8.6% of the infants. The objective of this study is to follow-up on infants with alleged nickel sensitivity.

METHODS

A total of 562 infants were included in the cohort and patch tested with nickel sulphate (ICDRG guidelines). The 26 children with a positive patch test reaction to nickel sulphate at 12 and 18 months were offered repeated patch tests at 3 and 6 yr.

RESULTS

Among the 21 children tested at both 12 months, 18 months and at 3 and 6 yr only 2 of 21 had reproducible nickel reactions (one clinically relevant), 13 of 21 were negative and 6 of 21 were negative at 3 or 6 yr.

CONCLUSIONS

Only 9.5% of the children had reproducible nickel sulphate reactivity, while 62% became negative. The results are noteworthy and can be interpreted in different ways: Repeated nickel patch tests did not cause patch test sensitization. The test reactions in infancy are probably of irritant or non-specific nature. Hence, nickel patch tests should only be performed in small children if there is a clinical suspicion of nickel-induced allergic contact dermatitis.

Coin exposure may cause allergic nickel dermatitis: a review

Nickel is used in coins because the metal has beneficial properties, including price, colour, weight, and corrosion resistance, and also because it is easy to stamp. It has often been claimed that the duration of skin contact with coins is too short to cause nickel release and dermatitis. However, it is well known by dermatologists specialized in occupational skin diseases, and by their nickel-allergic patients, that hand eczema in cashiers and other professionals who handle coins may be caused or aggravated by nickel release from coins. In this review, we present evidence from past studies showing that nickel-containing coins can indeed pose a risk for those who handle them. For protection of the health of consumers, cashiers, and other workers who handle coins, it is suggested that coins without nickel release should be used as a substitute for the high nickel-releasing coins currently in widespread use. The key risk factor in this situation is the ability of metal alloys in coins to release nickel and contaminate the skin after repeated contact from coin handling.

Surveillance of contact allergies: methods and results of the Information Network of Departments of Dermatology (IVDK)

Contact allergy (CA) surveillance networks provide information to a multitude of stakeholders, which is indispensable for evidence-based decision-making in the field of prevention. Methods and results of the German surveillance system on CA are reviewed and discussed with reference to other systems. The German network structure comprises 56 departments of dermatology and includes all patients who are patch-tested for suspected CA. Data analysis considers the results of patch testing and further pertinent information for each patient. Following aspects are addressed: (i) the description of the clinical population, (ii) evaluation of patch test reactions, (iii) relationship between patch test results and population characteristics. Trend analyses on chromate (decreasing), epoxy resin (increasing) and nickel (heterogeneous) served as examples for surveillance system analyses, with the identification of sentinel events, as well as proof of success or failure of prevention. In addition, external data sources can be used such as sales data of patch test preparations to estimate frequencies of sensitization on a population level. National prescription data of drugs and statistics of labelling of preservatives on cosmetics can be included, the latter two approaches allowing for risk estimates conferred by specific allergens.

Assessment of nickel and cobalt release from 200 unused hand-held work tools for sale in Denmark - Sources of occupational metal contact dermatitis?

INTRODUCTION

Nickel and cobalt allergy remain frequent in dermatitis patients. It is important to determine possible nickel and cobalt exposures at work as these may offer important information to regulators and physicians who perform patch testing. Clinical relevance of metal exposure is usually assessed by the treating physician via the medical history and by presentation of allergic contact dermatitis.

OBJECTIVES

To screen unused non-powered hand-held work tools for nickel and cobalt release by using colorimetric spot tests.

MATERIALS & METHODS

A random selection of 200 non-powered hand-held work tools for sale in 2 retailers of home improvement and construction products were analyzed qualitatively for metal release using the colorimetric nickel and cobalt spot tests.

RESULTS

Nickel release was identified from 5% of 200 work tools using the dimethylglyoxime (DMG) test. In 8 of 10, positive results were located to the metal ring that acts like a cuff and is located at the end of the grip. The positive DMG test results were not related to specific categories of work tools. The cobalt spot test gave no positive test reactions.

CONCLUSIONS

It appears that the proportion of work tools that release nickel, in amounts that may result in allergic nickel dermatitis, has decreased markedly, when results were compared with a Swedish study performed more than a decade ago. No cobalt release was detected but it should be underscored that hard-metal tools were not examined. Other sources of cobalt may explain the relatively high levels of cobalt allergy in dermatitis patients.

Contact allergy and human biomonitoring--an overview with a focus on metals

Humans are widely exposed to chemicals. Today, there is an increased acknowledgement of the importance of measuring human and environmental exposures to man-made or refined chemicals. Different approaches have been applied over time, but during the past 25 years, there has been a general trend towards the use of human biomonitoring. A few studies have used human biomonitoring methodology to track contact allergens together with information on patch test reactivity. Hypothetically, the internal load of reactive chemicals might modify the immune response to haptens and the propensity to sensitize and elicit allergic contact dermatitis or develop tolerance. This review offers a general overview of human biomonitoring, including information about its typical application and methodology. Furthermore, studies that have attempted to perform simultaneous biomonitoring and patch testing are reviewed. It is concluded that all studies conducted until the present have focused on one or two routes of exposure (typically skin and oral exposure, but also skin and airway exposure), whereas no studies have investigated all routes at the same time. Also, there is a need for prospective studies, as all epidemiological studies so far have been cross-sectional.

Exploring the molecular mechanisms of nickel-induced genotoxicity and carcinogenicity: a literature review

Nickel, a naturally occurring element that exists in various mineral forms, is mainly found in soil and sediment, and its mobilization is influenced by the physicochemical properties of the soil. Industrial sources of nickel include metallurgical processes such as electroplating, alloy production, stainless steel, and nickel-cadmium batteries. Nickel industries, oil- and coal-burning power plants, and trash incinerators have been implicated in its release into the environment. In humans, nickel toxicity is influenced by the route of exposure, dose, and solubility of the nickel compound. Lung inhalation is the major route of exposure for nickel-induced toxicity. Nickel can also be ingested or absorbed through the skin. The primary target organs are the kidneys and lungs. Other organs such as the liver, spleen, heart, and testes can also be affected to a lesser extent. Although the most common health effect is an allergic reaction, research has also demonstrated that nickel is carcinogenic to humans. The focus of the present review is on recent research concerning the molecular mechanisms of nickel-induced genotoxicity and carcinogenicity. We first present a background on the occurrence of nickel in the environment, human exposure, and human health effects.

Cobalt release from inexpensive jewellery: has the use of cobalt replaced nickel following regulatory intervention?

BACKGROUND

Before the introduction of the EU Nickel Directive, concern was raised that manufacturers of jewellery might turn from the use of nickel to cobalt following the regulatory intervention on nickel exposure.

OBJECTIVES

The aim was to study 354 consumer items using the cobalt spot test. Cobalt release was assessed to obtain a risk estimate of cobalt allergy and dermatitis in consumers who would wear the jewellery.

METHODS

The cobalt spot test was used to assess cobalt release from all items. Microstructural characterization was made using scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS).

RESULTS

Cobalt release was found in 4 (1.1%) of 354 items. All these had a dark appearance. SEM/EDS was performed on the four dark appearing items which showed tin-cobalt plating on these.

CONCLUSIONS

This study showed that only a minority of inexpensive jewellery purchased in Denmark released cobalt when analysed with the cobalt spot test. As fashion trends fluctuate and we found cobalt release from dark appearing jewellery, cobalt release from consumer items should be monitored in the future. Industries may not be fully aware of the potential cobalt allergy problem.

Metal allergy--a review on exposures, penetration, genetics, prevalence, and clinical implications

The prevalence of metal allergy is high in the general population, and it is estimated that up to 17% of women and 3% of men are allergic to nickel and that 1-3% are allergic to cobalt and chromium. Among dermatitis patients, the prevalence of metal allergy is even higher. Metal allergy is mainly an environmental disorder although null mutations in the filaggrin gene complex were recently found to be associated with nickel allergy and dermatitis. Environmental metal exposures include jewelry, buttons, clothing fasteners, dental restorations, mobile phones, and leather. Although consumer exposure is responsible for most cases of metal allergy, the importance of occupational metal exposure remains present and should always be taken into consideration when one interprets allergic patch test reactions to metals. Traditionally, nickel, cobalt, and chromium have been the most important contact allergens. However, recently, gold and palladium have drawn much attention as the prevalence of contact allergy to these metals is high. Palladium allergy is mainly a result of cross-sensitization to nickel, whereas gold allergy is rarely clinically relevant when one takes its high prevalence into account. The epidemiology of metal allergy has recently changed in Europe as nickel allergy among ear-pierced Danish women has decreased following regulatory intervention on nickel release from consumer products. In the United States, the prevalence of nickel allergy is still increasing, which may be explained by the absence of regulation. The prevalence of chromium allergy is increasing in the United States, Singapore, and Denmark among dermatitis patients. This increase is significantly associated with leather exposure in Denmark. Metal allergy may result in allergic contact dermatitis and systemic allergic (contact) dermatitis. Furthermore, metal allergy has been associated with device failure following insertion of intracoronary stents, hip and knee prostheses, as well as other implants. This area is in need of more research.