The prevalence of contact allergy in the general population has traditionally been investigated through population-based epidemiological studies. A different approach is the combination of clinical epidemiological (CE) data and the World Health Organization-defined drug utilization research (DUR) method. The CE-DUR method was applied in Denmark to estimate the prevalence of contact allergy in the general population and compare it with the prevalence estimates from the Glostrup allergy studies. Contact allergy prevalence estimates ranging from very liberal ('worst case') to conservative ('best case') assumptions were based on patch test reading data in combination with an estimate of the number of persons eligible for patch testing each year based on sales data of the 'standard series'. The estimated 10-year prevalence of contact allergy ranged between 7.3% and 12.9% for adult Danes older than 18 years. The 10-year prevalence of contact allergy measured by CE-DUR was slightly lower than previous prevalence estimates from the Glostrup allergy studies. This could probably be explained by a decrease in nickel allergy. The CE-DUR approach holds the potential of being an efficient and easy monitoring method of contact allergy prevalence.
In the summers of 2001 and 2002, we quantitatively sampled human-biting flies in twelve sites located 1.6 to 63 km from a large copper-nickel smelter at Monchegorsk on the Kola Peninsula, Russia. We collected 429 specimens of three species of Ceratopogonidae, 92 specimens of seven species of Culicidae, 76 specimens of seven species of Tabanidae, and 4,788 specimens of 19 species of Simuliidae. Culicoides chiropterus was for the first time reported from the Kola Peninsula. Catches of Culicidae and Simuliidae decreased near the smelter, presumably due to the combined action of toxicity of pollutants, pollution-induced forest damage, and decline in vertebrate density. An abundance of Ceratopogonidae and Tabanidae, the size of the most common black fly species, Simulium pusillum, and the diversity of all families did not change along the pollution gradient.
The aim of the present study was testing the hypothesis that the adoption of nickel-titanium rotary instrumentation (NTRI) will improve the technical quality of root-fillings. The investigation was carried out within a mandatory continuing education program (CEP) for general dental practitioners (GDPs). The study was conducted amongst GDPs employed by the Public Dental Health Service in the County of Stockholm. Identical questionnaires were distributed before the CEP (Pre-Q) and 9 to 12 months after the course (Post-Q). The CEP consisted of two parts: lectures and hands-on training. From each GDP, radiographs of two cases completed before the course and two cases treated 9-12 months after the course were randomly selected. Primarily molars were selected for evaluation. The radiographs were individually evaluated by two endodontists. Teeth treated before and after training were presented in random order. Adoption rate of NTRI increased from 35% to 75%. Cases from 124 GDPs were included in the final analysis. The rate of good quality root-fillings increased from 27% to 49% (p
Our aims in this study were to assess adverse patient reactions during orthodontic treatment with nickel-containing appliances and to investigate the need for and the use of nickel-free devices in orthodontic practices in Finland and Norway.
A questionnaire was mailed to orthodontists and dentists versed in orthodontics in both countries. They were asked to retrospectively assess the number of patients with adverse reactions and to describe the reactions, the appliances used, and any implications on treatment. Previous history of nickel allergy of patients with adverse reactions, and use of and need for nickel-free appliances in clinical practice were also addressed.
Forty-six percent of the respondents (n = 298) reported at least 1 adverse patient reaction during the last 5 years. More than half of the reactions had implications for the treatment. Finnish respondents observed significantly more adverse patient reactions than their Norwegian colleagues, and, in Finland, the adverse reactions were most frequently attributed to headgear treatment. Using nickel-containing fixed appliances in nickel-allergic patients was more common in Finland (77% of the respondents) than in Norway (65%).
Nearly half of the dentists regularly working with fixed appliances had observed at least 1 adverse patient reaction during treatment. Nickel-containing fixed appliances are generally used in most patients-even those with a suspected nickel allergy.
The effect of airborne pollution, especially nickel, from Kola has been studied in 10,612 persons who participated in a cardiovascular screening survey in Finnmark in 1974-75. The age-range was 35-49 years and a follow-up for death was conducted up to 1985. Men living in the community of Sør-Varanger (close to the border) had a relative risk (RR) for death from diseases of 1.2 (95% confidence intervall; 0.9-1.6) compared with the rest of Finnmark, for women RR = 1.1. The increase in mortality for men was due to infactus cordis RR = 1.5 (1.0-2.4), and was not consistent for women (RR = 0.9). The study does not support the view that air pollution in this area has increased the risk of death.
Allergic contact dermatitis in children is a significant clinical problem. Patch testing is a diagnostic tool for the evaluation of patients with suspected allergic contact dermatitis.
To determine the frequency and relevance of positive patch-test results in children and to identify the most common allergens in children at our clinic.
Retrospective chart review of 100 children and adolescents, aged 4 to 18 years, who were patch-tested at the Ottawa Hospital patch-testing clinic between 1996 and 2006. The children were patch-tested with the North American Contact Dermatitis Group (NACDG) standard series, supplementary series if indicated, and their own products if available.
Seventy percent of children had at least one positive patch-test reaction; 55.8% of positive patch-test reactions were relevant. The ratio of females to males was 62:38. The most common allergens were nickel sulfate (26%), cobalt (14%), fragrance mix (7%), neomycin (7%), colophony (6%), formaldehyde (4%), lanolin (4%), quaternium-15 (4%), and para-phenylenediamine (4%). Nickel co-reacted with cobalt (68%) and palladium (100%). Of children tested, 41% had a history of atopic dermatitis.
The frequency of positive and relevant allergens in children is similar to that in adults as compared with data from the NACDG 2001-2002 study period. Differences between the top 10 allergens in children and adults were seen. Nickel and cobalt were more common allergens in children, and colophony, lanolin, and para-phenylenediamine ranked in the top 10 allergens among children.
Although contact allergy among children was previously considered to be rare, data from the past decade have shown that it is common among children and that the prevalence may be increasing.
To describe the demographics of all children referred for patch testing in Denmark during 2003-2011, to examine the frequency and relevance of positive patch test reactions, and to assess the most common allergens.
A retrospective analysis of the patch test data from the Danish National Database of Contact Allergy was performed.
Of 2594 children and adolescents aged 1-17?years, 25.1% had one or more positive patch test reactions. The associated relevance was 66.4%. The most common sensitizers were metals, fragrances, and hair dyes. The frequency of positive patch test reactions and allergic contact dermatitis was significantly higher among girls.
Allergic contact dermatitis in children is a significant clinical problem. Contact allergy should always be considered when children with recalcitrant eczema are encountered, and special attention should be paid to girls. Patch testing is important, and children may be tested with the same patch test concentrations as adults.
A study of the prevalence of allergic patch test reactions to palladium chloride compared to nickel sulfate was performed in a group of Finnish schoolchildren. All adolescents 14-18 years of age in a Finnish town with 40,000 inhabitants, who had received orthodontic treatment with metallic appliances at a municipal dental clinic, were included in the study. The selection of patients was based on patient records. A non-treatment control group was randomly selected from the same age groups of the town population. A total of 700 subjects (77% of those invited), 417 (60%) girls and 283 (40%) boys, participated. The majority (91%) of the girls had pierced ears. Orthodontic treatment was equally common (67-70%) in the boys and the girls. The girls had a much higher frequency of allergic patch test reactions to both nickel sulfate and palladium chloride. Of the 700 adolescents tested, 48 (7%) had an allergic patch test reaction to palladium chloride. Of the 417 girls, 44 (11%) were palladium-chloride-positive, whereas only 4 of the 283 boys tested (1%) had an allergic patch test reaction to palladium chloride. 3 patients reacted to palladium chloride only, whereas all other patients with allergic patch test reactions to palladium chloride also had an allergic patch test reaction to nickel sulfate. The results support the concept of cross-reactivity between nickel sulfate and palladium chloride. The clinical significance of the allergic patch test reactions caused by palladium chloride remains unclear.
After inhalative occupational exposure to certain compounds containing nickel and chromium (mostly over many years), an accumulation of these metals may occur in the lung tissue. This is of particular importance, both from a toxicological point of view and with regard to expert reports, since certain nickel and chromium compounds may induce lung cancers. In the context of this study, samples of pulmonary tissue from 34 deceased persons from the Bergen area (Norway) were analysed by atomic absorption spectrometry with regard to their content of chromium and nickel. The deceased comprised 21 men and 13 women. In 15 cases, death resulted from lung cancer; in the other 19 deceased, there was no indication of a malignant disease of the airways. The concentrations of nickel found in the lung tissue do not differ between patients with lung cancer and patients with healthy lungs. On the other hand, the concentration of chromium in the pulmonary tissue in the patients who had died of lung cancer and who had all been inhalative smokers, are higher (statistically significant) than in the nonsmokers or in those with healthy lungs. An accumulation of these two metals in the tumor matrix could not be detected. Both the average nickel and the average chromium concentrations were higher in the persons who had probably been exposed occupationally. Considering the present state of scientific knowledge, the aspects relevant to expert reports which result from the analyses of metals in the pulmonary tissue are discussed.
Industrial hygiene surveys were conducted at three hot dip galvanizing plants to determine occupational exposure to nickel, zinc, and lead. All three plants employed the "dry process" and used 2% nickel, by weight, in their zinc baths. A total of 32 personal and area air samples were taken. The air samples were analyzed for nickel, zinc, and lead. Some samples were also analyzed for various species of nickel (i.e., metallic, soluble, and oxidic). The airborne concentrations observed for nickel and its three species, zinc, and lead at the three plants were all well below the current and proposed threshold limit values recommended by the American Conference of Governmental Industrial Hygienists (ACGIH).