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.
Nickel is the most frequent cause of contact allergy worldwide and has been studied extensively. This clinical review provides an updated overview of the epidemiology, exposure sources, methods for ...exposure quantification, skin deposition and penetration, immunology, diagnosis, thresholds for sensitization and elicitation, clinical pictures, prevention, and treatment. The implementation of a nickel regulation in Europe led to a decrease in the prevalence of nickel allergy, and changes in the clinical picture and disease severity. Nevertheless, the prevalences of nickel allergy in the European general population are approximately 8% to 19% in adults and 8% to 10% in children and adolescents, with a strong female predominance. Well‐known consumer items such as jewellery and metal in clothing are still the main causes of nickel allergy and dermatitis, although a wide range of items for both private and occupational use may cause dermatitis. Allergic nickel dermatitis may be localized to the nickel exposure site, be more widespread, or present as hand eczema. Today, efficient methods for exposure quantification exist, and new insights regarding associated risk factors and immunological mechanisms underlying the disease have been obtained. Nevertheless, questions remain in relation to the pathogenesis, the persistent high prevalence, and the treatment of severe cases.
Numerous studies have investigated the prevalence and risk factors of hand eczema in the general population. These studies are of high value as they tend to be less biased than studies using clinical ...populations and as they are important for healthcare decision makers when they allocate resources. This study aimed to review the epidemiology of hand eczema in the general population.
Literature was examined using Pubmed‐Medline, Biosis, Science Citation Index, and dermatology text books. On the basis of studies performed between 1964 and 2007, the point prevalence of hand eczema was around 4%, the 1‐year prevalence nearly 10%, whereas the lifetime prevalence reached 15%. Based on seven studies, the median incidence rate of hand eczema was 5.5 cases/1000 person‐years (women = 9.6 and men = 4.0). A high incidence rate was associated with female sex, contact allergy, atopic dermatitis, and wet work. Atopic dermatitis was the single most important risk factor for hand eczema. Hand eczema resulted in medical consultations in 70%, sick leave (> 7 days) in about 20%, and job change in about 10%. Mean sick time was longer among those with allergic hand eczema than those with atopic and irritant hand eczema. Moderate to severe extension of hand eczema was the strongest risk factor for persistence of hand eczema. Other risk factors included early onset of hand eczema and childhood eczema. The aetiology of hand eczema is multifactorial and includes environmental as well as genetic factors. Future studies should focus on unresolved areas of hand eczema, for example, genetic predisposition.
Summary
Nickel contact allergy remains a problem in EU countries, despite the EU Nickel Directive. To study the prevalence of nickel allergy in EU countries following the implementation of the EU ...Nickel Directive, we performed a systematic search in PubMed for studies that examined the prevalence of nickel allergy in EU countries published during 2005–2016. We identified 46 studies: 10 in the general population and 36 in patch tested dermatitis patients. A significantly lower prevalence of nickel allergy after than before the implementation of the EU Nickel Directive was found in women aged 18–35 years (11.4% versus 19.8%) (p = 0.02), in female dermatitis patients aged ≤17 years (14.3% versus 29.2%) (p < 0.0001), and in dermatitis patients aged 18–30 years (women: 20.2% versus 36.6%) (p < 0.0001) (men: 4.9% versus 6.6%) (p < 0.0001). Overall, the prevalence was higher in southern than in northern EU countries, and generally remained high, affecting 8–18% of the general population. A consistent pattern of decreasing prevalence of nickel allergy in some EU countries was observed, although the prevalence among young women remains high. Steps should be taken for better prevention of nickel allergy in EU countries.
A substantial number of studies have investigated the prevalence of contact allergy in the general population and in unselected subgroups of the general population. The aim of this review was to ...determine a median prevalence and summarize the main findings from studies on contact allergy in the general population. Published research mainly originates from North America and Western Europe. The median prevalence of contact allergy to at least 1 allergen was 21.2% (range 12.5–40.6%), and the weighted average prevalence was 19.5%, based on data collected on all age groups and all countries between 1966 and 2007. The most prevalent contact allergens were nickel, thimerosal, and fragrance mix. The median nickel allergy prevalence was 8.6% (range 0.7–27.8%) and demonstrates that nickel was an important cause of contact allergy in the general population and that it was widespread in both men and women. Numerous studies demonstrated that pierced ears were a significant risk factor for nickel allergy. Nickel was a risk factor for hand eczema in women. Finally, heavy smoking was associated with contact allergy, mostly in women. Population‐based epidemiological studies are considered a prerequisite in the surveillance of national and international contact allergy epidemics.
Summary
The history of chromium as an allergen goes back more than a century, and includes an interventional success with national legislation that led to significant changes in the epidemiology of ...chromium allergy in construction workers. The 2015 EU Leather Regulation once again put a focus on chromium allergy, emphasizing that the investigation of chromium allergy is still far from complete. Our review article on chromium focuses on the allergen's chemical properties, its potential exposure sources, and the allergen's interaction with the skin, and also provides an overview of the regulations, and analyses the epidemiological pattern between nations and across continents. We provide an update on the allergen from a dermatological point of view, and conclude that much still remains to be discovered about the allergen, and that continued surveillance of exposure sources and prevalence rates is necessary.
Background
In 2005, methylisothiazolinone (MI) was allowed as a stand‐alone preservative in cosmetics. This resulted in an epidemic of allergic contact dermatitis to MI, mainly affecting women ...exposed to leave‐on cosmetics. Consequently, a regulation of Annex V in the European Union in 2017 banned the use of MI in leave‐on cosmetics and reduced the allowed concentration in rinse‐off products.
Objective
To analyze the temporal trends in contact allergy to MI in Danish patients in relation to key events including European regulations over time.
Methods
A retrospective study of consecutive patients patch tested with methylisothiazolinone from 2005 to 2019. Demographics and clinical characteristics in terms of MOAHLFA (male, occupational, atopic dermatitis, hand dermatitis, leg dermatitis, facial dermatitis and age >40 years), sources of exposure, and clinical relevance were analyzed in relation to key historical events.
Results
Three hundred eighty of 12 494 patients (3.0%, 95CI: 2.7–3.4%) tested from 2005 to 2019 were sensitized to MI. An increasing trend in the prevalence of MI contact allergy from 2005 to 2019 (P < .01) was observed, although a decline in the absolute number of patch‐test positive patients was seen from 2013 and onward. A reduction in leave‐on cosmetics as a source of exposure was observed following the legislative ban in 2017, from 24.8% from in 2010 to 2013 to 6.2% in 2017 to 2019 (P < .01).
Conclusion
The epidemic of MI contact allergy is declining in absolute terms, although the prevalence in the patch‐tested population has not returned to its pre‐epidemic levels. The legislative regulation of MI in 2017 has been effective in terms of leave‐on cosmetics as a source of exposure in MI allergic patients. The process of post‐marketing risk assessment of contact allergens in the European Union needs improvement.
Filaggrin null mutations result in impaired skin barrier functions, increase the risk of early onset atopic dermatitis and lead to a more severe and chronic disease. We aimed to characterize the ...clinical presentation and course of atopic dermatitis associated with filaggrin mutations within the first 7 years of life.
The COPSAC cohort is a prospective, clinical birth cohort study of 411 children born to mothers with a history of asthma followed during their first 7 years of life with scheduled visits every 6 months, as well as visits for acute exacerbations of dermatitis. Atopic dermatitis was defined in accordance with international guidelines and described at every visit using 35 predefined localizations and 10 different characteristics.
A total of 170 (43%) of 397 Caucasian children developed atopic dermatitis. The R501X and/or 2282del4 filaggrin null mutations were present in 26 (15%) of children with atopic dermatitis and were primarily associated with predilection to exposed skin areas (especially the cheeks and back of the hands) and an up-regulation of both acute and chronic dermatitis. Furthermore, we found the filaggrin mutations to be associated with a higher number of unscheduled visits (3.6 vs. 2.7; p=0.04) and more severe (moderate-severe SCORAD 44% vs. 31%; p=0.14), and widespread dermatitis (10% vs. 6% of the body area, p<0.001) with an earlier age at onset (246 vs. 473 days, p<0.0001) compared to wild-type.
In children, filaggrin mutations seem to define a specific endotype of atopic dermatitis primarily characterized by predilection to exposed areas of the body, in particular hands and cheeks, and an up-regulation in both acute and chronic morphological markers. Secondary, this endotype is characterized by an early onset of dermatitis and a more severe course, with more generalized dermatitis resulting in more frequent medical consultations.
Cutaneous and systemic hypersensitivity reactions to implanted metals are challenging to evaluate and treat. Although they are uncommon, they do exist, and require appropriate and complete ...evaluation. This review summarizes the evidence regarding evaluation tools, especially patch and lymphocyte transformation tests, for hypersensitivity reactions to implanted metal devices. Patch test evaluation is the gold standard for metal hypersensitivity, although the results may be subjective. Regarding pre‐implant testing, those patients with a reported history of metal dermatitis should be evaluated by patch testing. Those without a history of dermatitis should not be tested unless considerable concern exists. Regarding post‐implant testing, a subset of patients with metal hypersensitivity may develop cutaneous or systemic reactions to implanted metals following implant. For symptomatic patients, a diagnostic algorithm to guide the selection of screening allergen series for patch testing is provided. At a minimum, an extended baseline screening series and metal screening is necessary. Static and dynamic orthopaedic implants, intravascular stent devices, implanted defibrillators and dental and gynaecological devices are considered. Basic management suggestions are provided. Our goal is to provide a comprehensive reference for use by those evaluating suspected cutaneous and systemic metal hypersensitivity reactions.
Background
Occupational contact dermatitis (OCD) is the most commonly recognized occupational disease in Denmark.
Objectives
To examine the impact of recognized OCD on degree of employment, sick ...leave, unemployment, and job change.
Methods
Data on all recognized individuals with OCD notified in Denmark between 2010 and 2015 (n = 8940) were linked to information on social transfer payments in the years before and after notification. The number of weeks on unemployment benefits or sick leave and the degree of employment during the 2 years prior to notification was compared with the 2 years following notification.
Results
The degree of employment decreased on average 8.9 work‐hours/month, corresponding to an average annual loss of income per worker of approximately €1570. The average number of weeks that workers were receiving unemployment benefits and paid long‐term sick leave rose by 2.5 and 3.4 weeks, respectively, corresponding to an average additional annual cost per worker of approximately €420 and €770, respectively. Longer case‐processing time was significantly associated with lower degree of employment and higher levels of unemployment and sick leave.
Conclusions
OCD has a significant negative impact on employment and economics, thus highlighting the need for a national, strategic action plan for effective prevention of OCD.