Atopic dermatitis at preschool age and contact allergy in adolescence: a population-based cohort study.

BACKGROUND: Atopic dermatitis (AD) is characterized by an impaired skin barrier, which can allow enhanced penetration of allergens. It is not clear whether AD influences the risk of developing contact allergy. OBJECTIVES: To examine the association between AD at preschool age and contact allergy at 16 years of age. METHODS: At 16 years of age, 2215 adolescents from the population-based cohort BAMSE were included. These adolescents had been followed with repeated questionnaires regarding AD throughout childhood, and contact allergy was assessed by skin patch test at 16 years. RESULTS: AD at preschool age was associated with contact allergy to at least one of the tested substances at 16 years of age among boys [adjusted odds ratio (OR) 1·51, 95% confidence interval (CI) 1·03-2·20] but not among girls (adjusted OR 0·77, 95% CI 0·54-1·10). AD at preschool age was not associated with contact allergy to nickel in either boys or girls. In contrast, AD at preschool age was associated with contact allergy to fragrance mix I (adjusted OR 3·10, 95% CI 1·66-5·80). This association was observed especially for AD at preschool age in combination with IgE sensitization to airborne or food allergens (adjusted OR 3·80, 95% CI 1·67-8·61). CONCLUSIONS: The results suggest that AD in early childhood may be associated with contact allergy to fragrances, but not to nickel, in adolescence.

Short contact with nickel causes allergic contact dermatitis: an experimental study.

BACKGROUND: Knowledge about the required duration of exposure for elicitation of allergic nickel dermatitis in nickel-allergic individuals is limited. However, it often has been proposed that short skin contact is safe. OBJECTIVES: To examine whether repeated skin contact with nickel over short time periods (3 × 10 min) can elicit allergic nickel dermatitis. METHODS: Sixteen nickel-allergic adults and 10 controls were exposed to, respectively, nickel- and aluminium-containing discs on each volar forearm and on each earlobe for 3 × 10 min. One arm was pretreated for 24 h with sodium lauryl sulfate (SLS) 0·5% under occlusion before exposure. One aluminium and one nickel exposure site were clinically evaluated, and blood flow was measured with laser Doppler flowmetry at day 2 and day 4. RESULTS: Ten of 16 (63%) nickel-allergic participants developed allergic nickel dermatitis on SLS-pretreated arm skin and three of 16 (19%) developed it on normal skin on the earlobe. On the SLS-pretreated arms of nickel-allergic participants, blood flow increased significantly more on the nickel-exposed skin than on the aluminium-exposed skin on days 2 and 4. No change in clinical reactivity or blood flow was found on normal forearm skin in nickel-allergic participants or on any skin in controls. CONCLUSIONS: This experimental study showed that relatively short repeated skin contact (3 × 10 min) with metallic nickel elicits allergic nickel dermatitis in irritated skin and at sites with previous dermatitis. The results support the restrictions in current nickel regulation.

Hand eczema and atopic dermatitis in adolescents: a prospective cohort study from the BAMSE project.

BACKGROUND: There is a well-known association between atopic dermatitis (AD) and hand eczema but less is known about how age at onset, persistence and severity of AD influence the risk of developing hand eczema. OBJECTIVES: To examine the role of AD in the occurrence of hand eczema in adolescence. In addition, associations between asthma and rhinoconjunctivitis, sensitization to common airborne and food allergens, and hand eczema were studied. METHODS: From the population-based birth cohort BAMSE, 2927 adolescents who had been followed up repeatedly concerning allergy-related disease were included. Questionnaires identified adolescents with hand eczema at 16 years, and their blood was analysed for specific IgE. RESULTS: A total of 152 (5·2%) adolescents had hand eczema at the age of 16 years. Many of these adolescents had a history of AD (n = 111; 73·0%) and asthma and/or rhinitis (n = 83; 54·6%), respectively. Children with AD (aged 0-16 years) had more than threefold increased odds ratios (OR) for having hand eczema; those with persistent or severe AD had a crude OR of 6·1 [95% confidence interval (CI) 4·0-9·1] and 5·3 (95% CI 2·9-9·6), respectively. CONCLUSIONS: We confirm a strong association between AD during childhood and hand eczema in adolescence. Children with persistent or more severe AD are at greater risk of developing hand eczema. Asthma and/or rhinoconjunctivitis, positive specific IgE or age at onset of AD are not associated with hand eczema in adolescence.

Methylisothiazolinone in rinse-off products causes allergic contact dermatitis: a repeated open-application study.

BACKGROUND: In recent years, the prevalence of contact allergy to the preservative methylisothiazolinone (MI) has increased dramatically. Cosmetic products are one of the major sources of exposure. OBJECTIVES: To examine whether allowed concentrations of MI in cosmetic rinse-off products have the potential to cause allergic contact dermatitis. METHODS: Nineteen MI-allergic subjects and 19 controls without MI allergy applied two liquid hand soaps five times per day on areas of 5 × 10 cm(2) on the ventral side of their forearms. One soap contained 100 ppm MI, the maximum allowed concentration in cosmetics, and was used by 10 allergic subjects and all controls. Another liquid soap with 50 ppm MI was used by nine allergic subjects. As the negative control, all subjects used a similar soap that did not contain MI. The repeated open applications proceeded until a positive reaction occurred or up to 21 days. The study was conducted in a randomized and blinded fashion. RESULTS: Ten out of 10 MI-allergic subjects developed positive reactions to the soap with 100 ppm and seven out of nine reacted to the 50 ppm soap, while none of the 19 controls had a positive reaction during 21 days of application. No reactivity was seen to the soap without MI. The difference in reactivity to MI between MI-allergic subjects and controls was statistically significant (Fisher's exact test, P ˂ 0.0001). CONCLUSIONS: Rinse-off products preserved with 50 ppm MI or more are not safe for consumers. No safe level has yet been identified.

Prevalence and incidence of hand eczema in adolescence: report from BAMSE--a population-based birth cohort.

BACKGROUND: BAMSE is a Swedish population-based birth cohort. OBJECTIVES: To estimate prevalence proportions and the incidence rate of hand eczema in Swedish adolescents, and to compare information given by adolescents and parents. Further aims were to study sex distribution, age at onset and extension of hand eczema. METHODS: At 16 years of age, 2927 adolescents were included in this study; both adolescent and parental questionnaires were used, as well as clinical examination. RESULTS: The 1-year prevalence of hand eczema was 5·2% (n = 152) and 4·0% (n = 116) (P < 0·03), and lifetime prevalence was 9·7% (n = 284) and 7·0% (n = 206) (P < 0·01), respectively, when adolescents and parents reported. The incidence rate was 573/100 000 person-years according to the adolescent report. The level of agreement between adolescents and parents was fair for 1-year and lifetime prevalence (κ = 0·56 and κ = 0·49, respectively). According to the Hand Eczema Extent Score, 27·0% (n = 36) had moderate-to-severe hand eczema. CONCLUSIONS: At the age of 16 years, the 1-year prevalence of hand eczema was substantial, with an incidence rate of the same magnitude as in adults. Female predominance was seen in adolescence. It is preferable that the occurrence of hand eczema is reported by adolescents themselves, as they are the ones most aware of their symptoms.

Excessive nickel release from earrings purchased from independent shops and street markets--a field study from Warsaw and London.

BACKGROUND: Nickel allergy is frequent and cause morbidity and increased health care costs. OBJECTIVE: The aim of this study was to determine the proportion of inexpensive earrings randomly purchased from stores and street markets in two capitals that gave positive dimethylglyoxime (DMG) test reactions and to determine whether the degree of nickel release was related to shop category. METHODS: Random inexpensive metallic earrings were purchased from stores and vendors in London and Warsaw. A qualitative investigation of nickel release by using the DMG test was performed. RESULTS: DMG testing revealed that respectively 15.1% (n=205) and 18.4% (n=206) of earrings purchased in London and Warsaw released nickel as indicated by positive test outcomes. Stratification by store category showed that DMG test-positive jewellery were mainly purchased from street markets and from stores that were not part of national or international chains. CONCLUSIONS: Despite the EU Nickel Directive having resulted in decreasing prevalence of nickel allergy, a large proportion of inexpensive earrings still release nickel in concentrations that may result in nickel allergy and dermatitis. Authorities should prioritize information campaigns and random inspections as a legislation that is not followed is of limited value.

Occupational skin exposure to water: a population-based study.

BACKGROUND: Occupational exposure to skin irritants, in particular to water, is an important risk factor for hand eczema. OBJECTIVES: To assess occupational skin exposure to water in the general population. METHODS: As part of a public health survey in Stockholm, Sweden, 18,267 gainfully employed individuals aged 18-64 years completed a questionnaire with previously validated questions regarding occupational skin exposure to water. RESULTS: Altogether 16% reported exposure to water for (1/2) h or more a day, and 13% reported exposure to water more than 10 times a day. Furthermore, 7% reported water exposure of more than 2 h and 6% of more than 20 times a day. Women reported more water exposure than men and many female-dominated occupations were seen to comprise water exposure. Women were also more exposed than men within the same jobs. Young adults were more exposed than older. A total of 18% were employed in high-risk occupations for hand eczema. Fifty-nine per cent of individuals employed in high-risk occupations reported water exposure at work, compared with 11% in low-risk occupations. CONCLUSIONS: A total of 20% of the population of working age acknowledged occupational skin exposure to water, which was found to be more common in young adults and women. Using job title as a proxy for water exposure gives an underestimation due to misclassification. In assessing occupational skin exposure to water, both exposure time and frequency should be considered.

Accumulation of eosinophils and T-lymphocytes in the lungs after exposure to pinewood dust.

Exposure to wood dust within the woodworking industry has been shown to cause a variety of respiratory disorders. The aim of this study was to investigate the cellular effects in bronchoalveolar lavage (BAL) fluid and peripheral blood from healthy individuals exposed to pinewood dust. Eleven healthy volunteers were exposed to pinewood dust for 1 h in a whole-body exposure chamber. BAL fluid and blood cells were differentially counted and the expression of activation, adhesion and subset markers on alveolar macrophages and T-lymphocytes was determined 2-6 weeks before and 20 h after the exposure. Following pinewood dust exposure, the total BAL fluid cell concentration increased from 81.4 (64.1-97.5) x 10(6) cells x L(-1) (median (interquartile range)) to 195.3 (154.6-341.2) x 10(6) cells x L(-1). The BAL fluid T-lymphocyte concentration increased from 3.8% (3.5-6.5%) to 7.6% (4.9-11.2%), and BAL fluid eosinophil concentration from 0.0% (0.0-0.2%) to 1.8% (0.6-3.5%). Inhalation of pinewood dust leads to the recruitment of inflammatory cells to the airways of healthy individuals. The increase in numbers of eosinophils, T-lymphocytes and mast cells, i.e. cells of crucial importance to airway inflammation, in the lungs may be related to the increased risk of developing respiratory disorders among woodworkers.

Lung accumulations of eosinophil granulocytes after exposure to cornstarch glove powder.

Starch is a main component of wheat flour, which, besides being an occupational allergen can also induce irritative symptoms in the airways. A purified starch product (cornstarch glove powder) was used to investigate whether starch alone could induce airway inflammation. The aim of the study was to investigate a role for starch in wheat flour-induced airway inflammation. Ten healthy individuals were exposed to cornstarch glove powder in a whole-body exposure chamber. Bronchoscopy with bronchoalveolar lavage (BAL) was performed 2-3 weeks before and 1 day after exposure, and the BAL cells were counted differentially. In addition, the expression of activation, adhesion and subset markers on alveolar macrophages and BAL T-cells were investigated using flow cytometry. A three-fold increase in BAL cell concentrations was found, with a selective accumulation and activation of eosinophilic granulocytes, as well as an influx of nonactivated monocytes and polyclonal CD4+ T-cells into the airways. The results show that inhalation of cornstarch glove powder leads to the development of a subclinical inflammation in the airways, with an accumulation of eosinophilic granulocytes. The authors suggest that such exposure may be an interesting model for studying factors contributing to lung accumulations of eosinophil granulocytes in humans.

Metals and women's health.

There is a lack of information concerning whether environmental-related health effects are more or less prevalent or manifested differently in women compared to men. Previously, most research in the area of toxicology and environmental and occupational health involved male subjects. The present work aims at reviewing exposure and health effects of cadmium, nickel, lead, mercury, and arsenic manifested differently in women than in men. The gender difference in exposure to nickel results in a much higher prevalence of nickel allergy and hand eczema in women than in men. The internal cadmium dose is generally higher in women than in men, due to a higher gastro-intestinal absorption at low iron stores. This was probably one major reason why Itai-itai disease was mainly a woman's disease. Yet, data are sparse regarding the risk for women relative to men to develop cadmium-induced kidney damage in populations exposed to low levels of cadmium. Lead is accumulated mainly in bone and increased endogenous lead exposure has been demonstrated in women during periods of increased bone turnover, e.g., menopause. Both lead and mercury exposure in pregnant women has to be kept low in order to prevent neurodevelopment effects in the developing fetus and child. Limited data indicate that women are more affected than men following exposure to methylmercury at adult age, while males seem to be more sensitive to exposure during early development. Regarding arsenic, some data indicate gender differences in the biotransformation by methylation, possibly also in susceptibility to certain arsenic-related cancers. Obviously, gender-related differences in exposure and health effects caused by metals are highly neglected research areas, which need considerable focus in the future.

Experiences from long-term research cooperation between Costa Rican, Nicaraguan, and Swedish institutions.

This paper summarizes experiences from long-term ongoing cooperation between Swedish research institutions and institutions at the National Universities in Nicaragua and Costa Rica. 24 researchers and teachers from the Central American institutions and ten Swedish research students have been trained. In addition to three full doctoral and three licentiate (two-year PhD program) theses, the two programs have so far published 15 articles in English-language, international, refereed journals and about three times as many abstracts for conferences in more than ten countries. A "sandwich" model for training is recommended, where the southern researchers come to the wealthier partner for collaborative analyses and write-ups of the publications, while spending 50-75% of their time in their home countries for data collection. Such collaboration should be planned for a time span of at least eight years and include substantial numbers of researchers and students. Means to minimize the risk of brain drain are suggested. The collaboration has been important for the globalization of the research cultures at the participating institutions and has trained international experts.

Legislative and preventive measures related to contact dermatitis.

Legislation can be a useful tool in the prevention of contact dermatitis. This is particularly true for dermatitis due to exposure to the many contact allergens that are chemical substances in products. A brief review is given of the most important European legislation--the EU Nickel Directive, the Cosmetics Directive, the Hazardous Substances Directive and the Hazardous Preparations Directive--and of some national regulations and standardization projects. It is concluded that it is essential that experts on contact dermatitis support, with their expert knowledge, national and European authorities.

Nickel release from coins.

Nickel allergy is the most frequent contact allergy and is also one of the major background factors for hand eczema. The clinical significance of nickel release from coins was discussed when the composition of euro coins was decided. Current European coinage is dominated by cupro-nickel coins (Cu 75; Ni 25); other nickel-containing and non-nickel alloys are also used. Nickel release from used coinage from the UK, Sweden and France was determined. It was shown that nickel ions are readily available on the surface of used coins. After 2 min in artificial sweat, approximately 2 microg of nickel per coin was extracted from cupro-nickel coins. Less nickel was extracted from non-nickel coins. Nickel on the surface was mainly present as chloride. After 1 week in artificial sweat approximately 30 microg/cm2 was released from cupro-nickel coins: less nickel was released from coins made of other nickel alloys. Theoretically, several microg of nickel salts may be transferred daily onto hands by intense handling of high-nickel-releasing coins.

Nickel on the Swedish market before the Nickel Directive.

Nickel allergy is by far the most frequent contact allergy, affecting 10-15% of women in the general population, and causing dermatitis and hand eczema. The EU Nickel Directive, aimed at the prevention of nickel allergy, comes fully into force by July 2001. The Directive covers piercing materials, items in contact with the skin, and requirements on resistance to wear. We carried out a study of the prevalence on the market, before the Nickel Directive, of items that release nickel and of nickel in piercing posts. Nickel release, as shown by a positive dimethylglyoxime (DMG) test, was detected in 25% of 725 items intended for direct and prolonged contact with the skin. Of 15 posts intended for use during epithelialization after piercing, 60% contained more than 0.05% nickel. These products do not comply with the requirements of the EU Nickel Directive. It is suggested that experts in contact dermatitis participate in the prevention of nickel allergy by explaining its effects: the r le of skin exposure and which parts of an item are in contact with the skin, and the crucial question of nickel release versus nickel content.

Self-diagnosed dermatitis in adults. Results from a population survey in Stockholm.

In a population-based survey of public health issues in Stockholm, Sweden, self-reported hand eczema, history of childhood eczema, nickel allergy, occurrence of skin symptoms on the face and intolerance to cosmetics and hygiene products, were investigated. A postal questionnaire was sent to 15,000 inhabitants aged 19-80 years. The response rate was 73%. The 1-year prevalence of hand eczema was 8% (females 10%, males 6%). History of childhood eczema was reported by 15% and, of these, 42% also stated positively that they had had hand eczema at some time. Hypersensitivity to nickel was owned to 15% of the females and 3% of the males. Of the nickel-sensitive, 30% reported ever having had hand eczema. The combination of nickel allergy and history of childhood eczema resulted in a cumulative prevalence of hand eczema of 56%. Females reported more hand-washings per day than did males, and a relation between number of hand-washings and hand eczema was found. Self-reported 1-year prevalence of skin symptoms on the face was 14% and, of these, 33% also owned to hypersensitivity to cosmetics. Dermatitis appears to be a common health problem. This fact should be made clear to those who give priority and allocate resources to health problems, e.g., by participation of dermatologists in performing population-based surveys.

Sensitizing potential of chlorothalonil in the guinea pig and the mouse.

The fungicide chlorothalonil is used extensively under several tradenames for the protection of various horticultural and fruit crops and bananas against fungal infections. It is also used as fungicide in wood preservation and as a preservative in paints. Clinical experience has shown chlorothalonil to be a contact allergen and several cases of allergic contact dermatitis attributed to chlorothalonil have been described. 2 previous guinea pig maximization test studies have shown the sensitizing potential of chlorothalonil to be high. The sensitizing property of chlorothalonil was studied by us with the predictive test methods the local lymph node assay and the cumulative contact enhancement test. In the local lymph node assay, chlorothalonil induced a dose-dependent increase in proliferation with a maximal stimulation index of 19.2 and 27.2. In the cumulative contact enhancement test, a statistically significant dose-dependent high sensitization rate was seen with a maximal sensitization rate of 100%. In conclusion, it is evident that chlorothalonil is an extremely potent contact allergen, inducing sensitization using only topical exposure on intact skin.