The association between hand eczema and nickel allergy has weakened among young women in the general population following the Danish nickel regulation: results from two cross‐sectional studies

Background: An association between nickel contact allergy and hand eczema has previously been demonstrated. In 1990, Denmark regulated the extent of nickel release in the ear‐piercing process as well as nickel release from consumer products. Objectives: This study aimed to evaluate the effect of the Danish nickel regulation by comparing the prevalence of concomitant nickel allergy and hand eczema observed in two repeated cross‐sectional studies performed in the same general population in Copenhagen. Materials: In 1990 and 2006, 3881 18–69 year olds completed a postal questionnaire and were patch tested with nickel. Data were analysed by logistic regression analyses and associations were expressed as odds ratios (ORs) with 95% confidence intervals (CIs). Results: The prevalence of concomitant nickel contact allergy and a history of hand eczema decreased among 18–35‐year‐old women from 9.0% in 1990 to 2.1% in 2006 (P < 0.01). The association between nickel contact allergy and a history of hand eczema decreased in this age group between 1990 (OR = 3.63; CI = 1.33–9.96) and 2006 (OR = 0.65; CI = 0.29–1.46). Among older women, no significant changes were observed in the association between nickel contact allergy and hand eczema. Conclusions: Regulatory control of nickel exposure may have reduced the effect of nickel on hand eczema in the young female population.     

Nickel and cobalt allergy before and after nickel regulation--evaluation of a public health intervention

Over the 20th century, the frequent use of nickel in consumer products resulted in an increasing prevalence of nickel allergy. Risk items included suspenders in the 1950s-1960s; buttons, zippers and rivets in the 1970s; and ear-piercing jewellery in the 1980s. When subjects allergic to nickel were exposed to nickel in high concentrations, it often resulted in allergic nickel contact dermatitis and hand eczema. In 1990, the Danish government began to regulate consumer nickel exposure as a response to the increasing nickel allergy problem. In 1994, the EU Nickel Directive was passed, a regulation that was based on the Danish and Swedish nickel regulations. These major public health interventions were expected to change the epidemiology of nickel allergy and dermatitis in Europe. Furthermore, it was debated whether nickel would be replaced by cobalt in inexpensive jewellery and result in higher prevalence of cobalt allergy. An evaluation of the possible effects of the European nickel regulations is of importance to ensure protection of consumers and dermatitis patients. This doctoral thesis aimed to evaluate the effects of regulatory interventions on nickel exposure by investigating the development of nickel allergy and dermatitis before and after nickel regulation. Furthermore, a change in the association between nickel allergy and hand eczema was evaluated. The nickel spot test was validated to determine its value when used for screening purposes. Possible explanations for the persistence of nickel allergy were explored including genetic predisposition and consumer nickel exposure from jewellery and accessories. A cobalt spot test was developed and validated. Finally, it was evaluated whether a cobalt allergy epidemic had replaced the nickel allergy epidemic after nickel regulation in terms of increasing cobalt sensitization and cobalt exposure. The thesis showed that the prevalence of nickel allergy decreased significantly after nickel regulation in young Danish women from the general population (18-35 years) and in young Danish female dermatitis patients from a university patch test clinic (0-30 years). Stratification by ear-piercing status revealed that women ear pierced before 1990 had a significantly higher prevalence of nickel allergy and dermatitis than women ear pierced after 1990. Furthermore, the association between hand eczema and nickel allergy decreased in young women aged 18-35 years when a comparison was made between women who were patch tested and questioned in, respectively, 1990 and 2006. Despite the decreasing prevalence of nickel allergy, this condition remains prevalent in young Danish women, as about 10% are nickel allergic. Genetic predisposition to nickel allergy was evaluated by investigating the possible association between filaggrin null mutation status and nickel allergy. A positive association was found but it was also concluded that environmental nickel exposure is of much greater importance. Thus, of 354 consumer items purchased from 36 different stores in Copenhagen, 22% released nickel in concentrations that may result in nickel dermatitis in sensitized subjects. Therefore excessive consumer nickel exposure remains common in Denmark and may be an important explanation for the persistence of nickel allergy. Excessive nickel release was also frequent when samples of earrings purchased in Warsaw and London were examined with the nickel spot test, in particular earrings purchased from street markets and shops with independent ownership. Only very weak indications of an emerging cobalt allergy epidemic were found, as the prevalence of cobalt allergy has not yet increased in young people and only four of 354 consumer items purchased in Copenhagen released cobalt in concentrations that may result in cobalt dermatitis in sensitized individuals. The specificity of the nickel spot test was 98% and the sensitivity 59%. Also, a cobalt spot test was developed and validated and seemed to be a useful diagnostic tool. In conclusion, the Danish nickel regulation and the EU Nickel Directive have changed the epidemiology of nickel allergy in Denmark. However, the Nickel Directive and its reference methods need to be revised to better protect consumers and dermatitis patients.     

Nickel sensitization in adolescents and association with ear piercing,use of dental braces and hand eczema. The Odense Adolescence Cohort Study on Atopic Diseases and Dermatitis (TOACS)

The prevalence of nickel allergy (sensitization) and the associations with ear piercing, use of dental braces and hand eczema were assessed in a cohort of 1,501 8th grade schoolchildren (aged 12-16 years) in Odense, Denmark. Nickel allergy was found in 8.6% and was clinically relevant in 69% of cases. Nickel allergy was found most frequently in girls and the association with ear piercing was confirmed. Application of dental braces (oral nickel exposure) prior to ear piercing (cutaneous nickel exposure) was associated with a significantly reduced prevalence of nickel allergy. In adolescents a significant association was found between hand eczema and nickel allergy. A follow-up study of this population is planned in order to assess the course and development of contact dermatitis, hand eczema and atopic diseases in adulthood and after choice of occupation.     

Contact allergy and allergic contact dermatitis in adolescents: prevalence measures and associations. The Odense Adolescence Cohort Study on Atopic Diseases and Dermatitis (TOACS)

The aims of this cross-sectional study were to establish the prevalence measures of contact allergy and allergic contact dermatitis in 8th grade schoolchildren (aged 12-16 years) in Odense, Denmark, and to examine the associations with atopic dermatitis, inhalant allergy and hand eczema. Contact allergy to a standard series allergen was found in 15.2% of schoolchildren. The point prevalence of allergic contact dermatitis was 0.7% and the lifetime prevalence 7.2%, predominantly in girls. The most common contact allergens were nickel (8.6%) and fragrance mix (1.8%). Nickel allergy was clinically relevant in 69% and fragrance allergy in 29% of cases. A significant association was found between contact allergy and hand eczema while no association was found between contact allergy and atopic dermatitis or inhalant allergy. In the future this cohort of schoolchildren will be followed with regard to the course and development of atopic diseases, hand eczema and contact dermatitis. Key words: school-     

Nickel allergy and hand eczema--a 20-year follow up

The aim of this study was to investigate the occurrence of hand eczema after 20 years in women patch tested to nickel during childhood. In 1982-1983, 960 schoolgirls were patch tested for nickel allergy; its prevalence was found to be 9%. 20 years later, the same individuals received a questionnaire regarding hand eczema and factors of importance for the development of hand eczema. 735 of 908 women (80.9%) answered the questionnaire. In total, 17.6% of respondents reported hand eczema after the age of 15 years, and the 1-year prevalence was 12.8%. There was no statistically significant difference in the occurrence of hand eczema between the groups who had previously tested positive and negative for nickel allergy. 38.3% of the respondents considered themselves to be nickel sensitive at the time they answered the questionnaire; in this group, the reported prevalence of hand eczema after age 15 was 22.5%. 31.4% of those with a history of atopic dermatitis reported hand eczema after age 15, compared with 10.6% of those without (P < 0.001). In conclusion, contact allergy to nickel in childhood did not seem to increase the prevalence of hand eczema later in life.     

Allergic contact dermatitis from dyes in wigs following diphencyprone treatment

Objectives:  To investigate symptoms from the eyes and airways, elicited by perfume and fragrance products and associations between such symptoms and skin prick test reactivity, metacholine bronchial hyperreactivity (BHR), contact allergy, and eczema in a population based sample.
Methods:  A questionnaire on mucosal symptoms elicited by fragrance products was mailed to 1189 persons who had participated in a Danish population‐based study of allergic diseases in 1997/98. The study included measurement of BHR, skin prick testing, patch testing and history of hand eczema.
Results:  The response rate to the questionnaire was 80%. Symptoms from the eyes or airways elicited by fragrance products were reported by 42%. There were no significant associations between these symptoms and skin prick test reactivity. Positive and independent statistical significant associations were found between BHR, perfume contact allergy and hand eczema, and symptoms from the eyes and airways elicited by fragrance products, also when adjusting for nickel contact allergy, age, gender psychological vulnerability, educational level and social class.
Conclusions:  Individuals with BHR, hand eczema and/or perfume contact allergy, as opposed to those without, are more frequently and more severely bothered from the eyes or airways after volatile exposure to fragrance products. The lack of association with skin prick test reactivity indicates that IgE mediated allergic mechanisms do not play a major role in the development of these symptoms. Having hand eczema has the greatest impact on reporting mucosal symptoms elicited by fragrance products.     

Prevalence of atopic dermatitis, asthma, allergic rhinitis, and hand and contact dermatitis in adolescents. The Odense Adolescence Cohort Study on Atopic Diseases and Dermatitis

BACKGROUND: Atopic diseases are common in children and adolescents. However, epidemiological knowledge is sparse for hand eczema and allergic contact dermatitis in this age group. Furthermore, no population-based studies have evaluated the prevalence of atopic diseases and hand and contact dermatitis in the same group of adolescents. OBJECTIVES: To assess prevalence measures of atopic dermatitis (AD), asthma, allergic rhinitis and hand and contact dermatitis in adolescents in Odense municipality, Denmark. METHODS: The study was carried out as a cross-sectional study among 1501 eighth grade school children (age 12-16 years) and included questionnaire, interview, clinical examination and patch testing. RESULTS: The lifetime prevalence of AD was 21.3% (girls 25.7% vs. boys 17.0%, P < 0.001) using predefined questionnaire criteria. The 1-year period prevalence of AD was 6.7% and the point prevalence 3.6% (Hanifin and Rajka criteria). In the interview the lifetime prevalence of inhalant allergy was estimated as 17.7% (6.9% allergic asthma, 15.7% allergic rhinitis). The lifetime prevalence of hand eczema based on the questionnaire was 9.2%, the 1-year period prevalence was 7.3% and the point prevalence 3.2%, with a significant predominance in girls. A significant association was found both between AD and inhalant allergy, and between AD and hand eczema using lifetime prevalence measures. The point prevalence of contact allergy was 15.2% (girls 19.4% vs. boys 10.3%, P < 0.001), and present or past allergic contact dermatitis was found in 7.2% (girls 11.3% vs. boys 2.5%). Contact allergy was most common to nickel (8.6%) and fragrance mix (1.8%). CONCLUSIONS: High prevalence figures were found for atopic diseases, hand eczema and allergic contact dermatitis, and the diseases were closely associated. A considerable number of adolescents still suffers from AD, and a considerable sex difference was noted for hand eczema and allergic contact dermatitis. Nickel allergy and perfume allergy were the major contact allergies. In the future this cohort of eighth grade school children will be followed up with regard to the course and development of atopic diseases, hand eczema and contact dermatitis.     

Allergic contact dermatitis from natural latex.

BACKGROUND: Reports on natural latex allergy have increased steadily during the last 10 years. Latex allergy generally refers to a type 1 reaction to natural rubber latex (NRL) proteins with clinical manifestations ranging from contact urticaria to asthma and anaphylaxis. Previous United States studies on NRL allergy largely have been reported by allergists with little detailed information on hand eczema, contact allergy, or on outcome. The present study was performed from March 1998 to November 1999 with the aim of finding out the prevalence of type IV hypersensitivity to latex in patients with suspected rubber allergy. MATERIALS AND METHODS: A total of 167 patients with hand eczema and contact with rubber products underwent patch testing with the standard screening and rubber components (test series Deutsche Kontaktallergiegruppe), and NRL pure provided by Regent (liquid high ammonia 0.7% NRL, accelerator, and preservative-free latex) between March 1998 and November 1999. The charts of all NRL positive patients are reported with the results of history, prick, patch tests, total IgE, specific IgE to latex (FEIA) test and follow-up data (after 6 months). RESULTS: Four patients (3 men) showed positive patch test results to NRL. One of these patients also reacted to the rubber chemical tetraethylthiuram monosulfide, and another one of these patients revealed a type 1 reaction to NRL, diagnosed by positive reaction to prick test. The other 3 patients with patch test reactions to NRL had negative reactions to prick tests to NRL extracts after 20 minutes. All 4 patients had a positive delayed prick test reaction to NRL. Latex FEIA test result was negative in all 4 patients. The contact eczema healed after elimination of the latex gloves and medical latex devices in all patients. Furthermore, 10 of the 167 patch testing patients (6%) were positive for tetramethylthiuram monosulfide 1%. CONCLUSION: In the present study with 167 patients, the prevalence of type IV hypersensitivity to latex was 2.4%. We recommend that the patch test with NRL as well as with rubber additives should be performed in patients of suspected contact dermatitis caused by rubber products.     

Incidence of allergic contact sensitization in Danish adults between 1990 and 1998; the Copenhagen Allergy Study,Denmark

BACKGROUND: Studies of incidence of contact allergy in a general population have not been reported. Data from incidence studies may support and direct strategies for prevention of contact allergy and allergic contact dermatitis. OBJECTIVE: To study the incidence of contact allergy and evaluate risk factors for developing contact allergy in an adult general population sample. PATIENTS AND METHODS: In 1990 a random sample of 567 persons of the 15-69-year-old population living in the western part of Copenhagen County (Denmark) was patch tested in a cross-sectional study. In 1998 a follow-up study was performed. Of 540 invited, 365 (68%) were patch tested again. RESULTS: In the follow-up study, 37 persons (12%) of the 313 patch-test-negative persons in 1990 had developed one or more positive patch tests (incident contact allergy). Twenty cases (6%) of incident nickel allergy and 25 cases (8%) of incident contact allergy to one or more haptens other than nickel were found. The data indicate that female sex, young age and ear piercing (before 1990) were risk factors for developing nickel allergy. Between 1990 and 1998 metal contact dermatitis was reported in seven women with incident nickel allergy. Six of these women had bought the eliciting item in Denmark before 1995, when vigorous control of the Danish nickel legislation was introduced. CONCLUSIONS: We found a considerable number of incident cases of contact allergy in the adult population. The results of the study support the actions taken to restrict the use of the allergens most frequently encountered, and to increase the labelling demands to products intended for prolonged contact with the skin or a combined action.     

Genetic factors in nickel allergy evaluated in a population-based female twin sample

Environmental exposures are important for development of allergic contact dermatitis, but genetic factors have been proposed to be of additional importance for contact sensitization. Recently genetic factors were shown to be of significance for hand eczema. In this study, a sample of twins recruited on the basis of hand eczema has been evaluated with respect to influence of genetic factors on development of nickel sensitization. A total of 1076 individual twins were patch tested and underwent clinical examination, and in the final genetic statistical analysis 630 females were available, of which 146 had a positive patch test to nickel. The aggregation of nickel allergy among twin pairs was measured by the casewise concordance and the twin odds ratio. The twin odds ratio were adjusted for effects of risk factors known to be associated with nickel allergy, namely, wet work, atopic dermatitis, and self-reported hand eczema. There was a small tendency for larger odds ratio among monozygotic twins than among dizygotic twins, which was not statistically significant. As a result of the statistical analysis, it is concluded that allergic nickel contact dermatitis is mainly caused by environmental and only to a lesser degree genetic factors. The selection of twins on the basis of hand eczema may theoretically influence the prevalence of nickel allergy and concordance estimates, which should be considered before extrapolating the data to a random population-based twin sample.     

Nickel allergy from adolescence to adulthood in the TOACS cohort

Background In 1995, we established a cohort of 1501 unselected eighth‐grade schoolchildren to investigate the course of nickel allergy into adult life. Objectives To follow the course of nickel allergy and clinically relevant nickel dermatitis over 15 years from adolescence to adulthood, and the effect of ear piercing, atopic dermatitis and degree of nickel patch test reactivity. Methods One thousand two hundred and six young adults from the cohort were asked to complete a questionnaire and participate in a clinical examination including patch testing with TRUE Test® including a nickel dilution series. Results The questionnaire was answered by 899 (74.6%), and 442 (36.7%) had patch tests performed. The point prevalence of nickel allergy was 11.8% (clinical relevance 80.8%). The 15‐year incidence rate was 6.7%. Most new sensitizations were clinically relevant with strong reactions, and many participants reacted to low concentrations. Only a few positive reactions were lost. Nickel allergy was more common among women with childhood atopic dermatitis, whereas no association with ear piercing was found. However, there was a significantly higher prevalence of nickel allergy among women ear pierced before implementation of the nickel regulation in Denmark. Conclusion This follow‐up study in young adults 15 years after leaving primary school showed a high prevalence and a high incidence rate of nickel allergy, despite the nickel regulation. Most reactions from childhood could be reproduced and were clinically relevant. In women, childhood atopic dermatitis was associated with nickel allergy in adulthood, whereas only ear piercing before the Danish nickel regulation was associated with adult nickel allergy.     

Hand eczema in car mechanics

To estimate the prevalence of hand eczema, a questionnaire was distributed to 901 male car mechanics. Of the 801 persons who responded, 15% reported hand eczema on some occasion in the previous 12 months, and 57% admitted dry skin on the hands. In a 2nd part of the study, those who reported hand eczema were examined and patch tested with a standard series and a special "car mechanics' series". The most common diagnosis was irritant contact dermatitis, 55%, and 2nd was allergic contact dermatitis, 19%. 35/105 (33%) had a total of 51 positive patch test reactions, all to substances in the standard series, except for 2 persons who reacted to oxidized d -limonene. The most frequent reactions were to thimerosal (9%), nickel (8%) and colophony (5%). One plausible explanation for the high prevalence of nickel allergy was the common use of nickel-plated tools. 5 individuals had a history of contact urticaria, but scratch tests were negative. It was concluded that car mechanics are at high risk for contact dermatitis on the hands, irritant as well as allergic.     

Prevalence of nickel allergy among Finnish university students in 1995

Nickel allergy was studied in a sample of 1st-year university students starting their studies in 1995. A total of 296 subjects (72%) of 413 invited participated in the clinical examination, and 284, 96 male and 188 female, were patch tested (69%). A history of nickel sensitization was enquired for. Prick tests and serum specific IgE levels were determined. Occurrence of atopic dermatitis, hand eczema, and current exposure to metals were recorded. Nickel allergy was encountered in 39% of all female students, in 42% of females with pierced skin, and in 14% of females without pierced skin. The corresponding figures for males were 3%, 7% and 3%. In the multiple regression analysis, the risk factors for nickel allergy were female sex (OR 8.1, p<0.01), current metal exposure at examination (OR 4.1, p<0.01) and skin piercing (OR 3.6, p<0.05). Positive prick tests or elevated IgE levels to common allergens were not significantly associated with nickel allergy. In female students, the prevalence of nickel allergy has increased from 13% in 1986 to 39%. The prevalence among males has remained low at 3%. The results indicate that, in addition to skin piercing, current metal contacts are important risk factors for nickel allergy. This finding gives support to the EU Nickel Directive.     

Occupational hand eczema in an industrial city

Hand eczema in relation to occupation was studied in an industrial city. Questionnaires were sent to 20,000 individuals aged 20-65 years, randomly selected from the population register of the city. Those subjects (1385) considering themselves to have had hand eczema within the previous 12 months were invited to a dermatological examination including patch testing. It was found that the reported 1-year period prevalence of hand eczema in the total sample was 11.8%. The only occupational group reporting a statistically significant higher 1-year period prevalence was service work, 15.4%. Among all occupations, cleaners turned out to have the highest period prevalence, 21.3%. Hand eczema was more common among people reporting some kind of occupational exposure. The most harmful exposure turned out to be to unspecified chemicals, water and detergents and dust and dry dirt. The use of protective gloves is reported and analysed. The most common contact allergy was nickel, followed by cobalt, fragrance-mix, balsam of Peru and colophony. A statistically significant increase in contact allergy to colophony for women in administrative work was found. It is concluded that the type of hand eczema that is mostly dependent on occupation is irritant contact dermatitis.     

Fluctuations in the prevalence of chromate allergy in Denmark and exposure to chrome-tanned leather

Background. A recent Danish study showed a significant increase in the prevalence of chromate contact allergy after the mid‐1990s, probably as a result of exposure to leather products. Objectives. To reproduce the results by analysing data from the period 1992–2009 at Odense University Hospital, Denmark. The temporal development in the occurrence of chromate contact allergy and assumed causative exposures were investigated. Patients, Materials and Methods. A retrospective analysis of patch test data was performed (n = 8483), and medical charts from patients with chromate allergy (n = 231) were reviewed. Comparisons were made using the χ²‐test. A test of the reproducibility of the TRUE Test^® was also performed. Logistic regression analyses were used to test for associations. Results. No significant changes in the prevalence or exposure sources of chromate allergy during 1992–2009 were identified. Leather shoes (24.4%) were the most frequent exposure sources in chromate allergy, and were mainly registered in women, although the difference between men and women was not significant (P = 0.07). Cement and leather glove exposure occurred significantly more often in men than in women (P = 0.002). Foot dermatitis (40.3%) was the most frequent anatomical location, apart from hand eczema (60.6%). The reproducibility of the TRUE Test^® was 93.3%. Conclusions. Apart from hand eczema, the most frequent clinical picture of chromate allergy was foot dermatitis caused by leather shoe exposure. A tendency for an increasing prevalence of chromate contact allergy from 1997 was shown, but no significant change was detectable.     

Cobalt release from implants and consumer items and characteristics of cobalt sensitized patients with dermatitis

Background. Cobalt allergy is prevalent in dermatitis patients. Very little documentation exists about current sources of cobalt exposure. Objectives. To investigate and discuss putative sources of cobalt exposure and to present selected epidemiological data on cobalt allergy from patch‐tested dermatitis patients in an attempt to better understand cobalt allergy. Materials and methods. 19 780 dermatitis patients aged 4–99 years were patch tested with nickel, chromium or cobalt between 1985 and 2010. The cobalt spot test was used to test for cobalt ion release from mobile phones as well as cobalt‐containing dental alloys and revised hip implant components. Results. Six of eight dental alloys and 10 of 98 revised hip implant components released cobalt in the cobalt spot test, whereas none of 50 mobile phones gave positive reactions. The clinical relevance of positive cobalt test reactions was difficult to determine in the majority of patients. Isolated patch test reactivity to cobalt was less associated with occupational dermatitis and hand eczema than patch test reactivity to cobalt in combination with other contact allergies. Conclusions. It is often difficult to interpret the relevance of a positive patch test reaction to cobalt, and there is a need for further studies to determine sources of cobalt exposure.     

An epidemiological comparison between hand eczema and non-hand eczema

Thirty four per cent of 2110 patients with eczema attending a contact dermatitis clinic presented with hand eczema. An epidemiological comparison was made of patients with hand eczema and non-hand eczema (defined as eczema on parts of the body other than the hands). Occupational eczema was significantly more common in the hand eczema than the non-hand eczema group (P = 0.0011). The prevalence of atopy was the same in both groups (13%). The prevalence of irritant contact dermatitis was higher in the hand eczema group (32%) than the non-hand eczema group (13%) (P less than 0.0001). The rate of allergic contact dermatitis was lower in the hand eczema group (23%) than the non-hand eczema group (39%) (P less than 0.0001). The rate of positive patch test reactions was lower in the hand eczema group (41%) than the non-hand eczema group (56%) (P less than 0.0001). Nickel sulphate (8%), cobalt chloride (3%), potassium dichromate (3%), and fragrance mix (4%) were common allergens encountered in hand eczema group. None of these allergens was specifically more prevalent in the hand eczema than the non-hand eczema group. However, the prevalence of allergy to nickel, colophony, epoxy resin and medicaments was significantly higher in the non-hand eczema group.     

Contact sensitivity and urticaria in "wet" work

A selected group of 142 hospital “wet” workers with hand eczema was studied. 91% were female. Atopy (58%), metal dermatitis (41%), and hand eczema prior to the current wet work (67%) were more common than in the total cohort to which these patients belonged. Patch tests were carried out on 120 patients and prick tests on 41 with a history of contact urticaria. Water, cleaning agents, hand disinfectants, the wearing of gloves and other trivial irritant factors were claimed to have elicited the current episodes of hand eczema in 92.3% of cases. In 35%, a considerable part of the exposure to irritant factors look place at home or during leisure time. Delayed contact sensitivity was found in 45 patients, nickel, cobalt, balsam of Peru and rubber chemicals being the most common allergens. Nickel and/or cobalt allergy was found in approximately half of the patients with contact allergy. Positive prick tests relevant for contact urticaria were found in 22 patients, and were most often obtained with various foods or rubber gloves. Although contact sensitivity and contact urticaria were common, they seemed to play a minor rôle in the etiology of the current hand eczema compared to endogenous factors and trivial irritants.     

Individual variation in nickel patch test reactivity.

BACKGROUND AND OBJECTIVE: Various factors such as hormones, drugs, and ultraviolet (UV) radiation may influence patch test reactions. The aim was to study the individual variation in nickel reactivity, also in relation to the menstrual cycle. METHODS: Thirty women allergic to nickel were studied for 7 months with patch tests with a serial dilution of nickel sulfate in water on four different test occasions. The patients belonged to two different eczema groups, one with nickel allergy, atopy, and pompholyx (12 patients); and the other with nickel allergy, but without both atopy and hand eczema. RESULTS: None of the patients showed the same patch test reactivity on all four occasions, and the highest individual difference noticed was 250 times for the four test occasions. Furthermore, two of the patients had completely negative test reactions on at least one test occasion. CONCLUSION: The variation in nickel reactivity as shown in this article is of great importance and should be kept in mind when a patient has a positive history of allergic contact dermatitis but negative patch test results to nickel.