Water Exposure on the Hands in Adolescents: A Report from the BAMSE Cohort

Water exposure on the skin of the hands has previously been studied in adults. The aim of this study was to investigate self-reported water exposure in adolescents in the BAMSE cohort in Stockholm, Sweden. A questionnaire including a question on daily water exposure on the hands was answered by 3,091 adolescents at age 16 years. Exposure < 10 times/day was reported by 28.7% and < 20 times/day by 3.1%; boys had somewhat higher exposure than girls (p = 0.03). In a multivariate analysis, adolescents with dry skin reported higher exposure (adjusted odds ratio (ORadj) 1.4; 95% CI 1.2-1.7), while no statistically significant exposure differences were found in relation to hand eczema or atopic dermatitis. Reported exposure may be considered as baseline exposure during a period of life with limited occupational and domestic duties.

Scoring of Hand Eczema: Good Reliability of Hand Eczema Extent Score (HEES)

There is good agreement between dermatological staff and patients using the Hand Eczema Extent Score (HEES). The aim of this study was to assess inter- and intra-observer reliability of the HEES in dermatologists and intra-observer reliability of the HEES in patients with hand eczema. Six dermatologists assessed 18 patients twice. Only the hands of the patients were visible to the assessors. Patients performed a self-assessment twice. Inter- and intra-observer reliability was tested with intraclass correlation coefficient (ICC). The mean HEES score for all dermatologists' assessments was 21.0 (range 3.6-46.3). The corresponding mean scores for all patients' own assessments were 24.9 (range 4.0-54.0). Inter-observer reliability in the dermatologists' observations ICC classification was very good, median value 0.82 (range 0.56-0.92). The overall intra-observer reliability for the 6 dermatologists' ICC classification was very good (range 0.88-0.94). Intra-observer reliability in the patients' 2 self-assessments ICC classification was very good (ICC 0.95). In conclusion, HEES is a reliable tool for both dermatologists and patients to grade the extent of hand eczema.

Disability Pensions due to Skin Diseases: A Cohort Study in Swedish Construction Workers

Disability pensions due to skin diseases in Swedish male construction workers were studied by linking data from pension registers and an occupational health service. Incidence rates of disability pensions for cement workers, painters and plumbers were compared with 2 control groups. A total of 623 disability pensions were granted during 4 decades of follow-up. The main diagnoses were eczema (36%) and psoriasis (49%). Pensions were mostly granted in the age range 55-64 years. Among painters, cement workers and plumbers the incidence rates for disability pensions were 33.3, 24.5 and 20.4 cases/100,000 person-years, respectively, compared with 13.7 and 9.2 cases/100,000 person-years in control groups. Relative risks were highest for eczema, and were notable for psoriasis. Attributable fractions for eczema were 90% in cement workers and painters and 75% in plumbers compared with control groups. Attributable fractions for psoriasis in the occupational groups studied were in the range 54-67%. In conclusion, eczema and psoriasis have a high impact on loss of work ability, as reflected by disability pensions.

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.

Hand eczema and use of snus (moist snuff) - a population-based study

A possible association between use of snus (Swedish moist snuff) and hand eczema was studied. 27,466 individuals responded to questions regarding hand eczema, tobacco use and other life style factors in a Swedish Public Health Survey in 2006, response rate 58%. Of these persons, 12.2% reported daily snus use (men 22.0%, women 4.3%), 15.5% daily smoking (men 14.4%, women 16.5%). Of snus users 7.5 % reported hand eczema (men 6.5%, women 11.8%), of smokers 11.7% (men 8.6%, women 13.6%) and of non-tobacco-users 9.7% (men 7.9%, women 11.0%). In multivariate analysis hand eczema was significantly less common in snus users, in total prevalence proportion ratio (PPR) =  0.813, in men PPR =  0.820, but significantly more common in smoking women, PPR = 1.238. Physical exercise was a confounder; gender an effect modifier. No positive association was demonstrated between snus use and hand eczema in contrast to the positive association found between smoking and hand eczema in women.

Exposure of hairdressers to ortho- and meta-toluidine in hair dyes

BACKGROUND

Carcinogenic aromatic amines derived from hair dyes have recently received new attention. One of these is ortho (o)-toluidine, which is classified as carcinogenic to humans.

OBJECTIVES

To clarify exposure of hairdressers to potentially carcinogenic aromatic amines, including o-toluidine.

METHODS

We measured eight potentially carcinogenic aromatic amines in the blood of 295 hairdressers, 32 users of hair dyes and 60 controls. The study was restricted to female non-smokers. Lifestyle data were collected for all participants using self-administered questionnaires. Blood samples were taken for analysis of ortho-, meta (m)- and para (p)-toluidine; 2-, 3- and 4-ethylaniline, 2,3- and 3,4-dimethylaniline as haemoglobin adducts. The samples were analysed with gas chromatography-tandem mass spectrometry.

RESULTS

Generally, adduct concentrations were in the range of 0-200 pg/g haemoglobin. A comparison of the adduct concentrations found in hairdressers, consumers and controls showed no statistically significant differences. However, for hairdressers, o- and m-toluidine concentrations increased significantly with the weekly number of hair waving (p=0.020) and permanent hair dyeing treatments (p=0.026), respectively. o-Toluidine and m-Toluidine concentrations also tended (p=0.076 and 0.080, respectively) to increase with the frequency of light-colour permanent hair dye treatments.

CONCLUSIONS

Hairdressers who use light-colour permanent hair dyes, other permanent hair dyes and hair waving treatments seem to be exposed to o- and m-toluidine as indicated by associations with the number of treatments performed. Analyses of hair waving and hair dye products should be performed to identify the possible sources of exposure to o- and m-toluidine.

Is skin exposure to water mainly occupational or nonoccupational? A population-based study

BACKGROUND

Skin exposure to water is considered to contribute to hand eczema. Knowledge about total water exposure during a day is scanty.

OBJECTIVES

To investigate self-reported water exposure at work as well as throughout the day.

METHODS

Skin exposure to water was assessed from two questionnaire-based health surveys: the nationwide Environmental Health Survey 2007 (EHS), which enquired about water exposure throughout the day, and the Stockholm Public Health Survey 2006 (PHS), which probed water exposure at work. Answers from 19,667 individuals (EHS) and 18,318 individuals (PHS) were available for analysis.

RESULTS

In total, 22% of respondents (women 30%, men 12%) reported skin exposure to water more than 20 times during an entire day (EHS) compared with 6% (women 8%, men 4%) at work (PHS). In a univariate analysis, using a merged file comprising data from the EHS and the PHS, water exposure more than 20 times a day was more common in the EHS (prevalence proportion ratio 3·570, 95% confidence interval 3·353-3·802). In multivariate models the variables studied did not fulfil the criteria for being confounders. Water exposure at work declined with increasing age in both women and men (P < 0·0001) as did water exposure during the entire day in men (P < 0·0001). However, women were equally exposed during the entire day across age groups (P = 0·205).

CONCLUSIONS

High water exposure over the entire day was found to be considerably more frequent than exposure at work. Thus, a significant proportion of water exposure seems to occur outside work. This should be considered in prevention of hand eczema and when counselling patients with hand eczema in clinical practice.

Primary prevention of latex allergy in healthcare-spectrum of strategies including the European glove standardization

IgE-mediated allergy to natural rubber latex was first noted from rubber gloves in 1979. The initial reports in dermatological journals described contact urticarial reactions; later, severe generalized allergic reactions and asthma were documented. A considerable proportion of the people involved in medical and dental care were found to be sensitized to latex. This article describes and surveys a broad range of primary prevention measures at the local and national levels. Examples are given from paediatrics, dental education, and medical care. National strategies and position papers on latex allergy are presented in which medical professionals, manufacturers and public authorities have cooperated. Special reference is paid to the European work to standardize medical gloves, which led to document EN 455:3.

Validation of self-testing as a method to estimate the prevalence of nickel allergy

The aim of this study was to investigate the validity of self-patch testing for nickel allergy, in order to determine a cost-effective method for surveillance of the prevalence of nickel allergy. Population-based study including patch testing is the most reliable method to study the prevalence of allergy, but it is expensive and has logistical problems. A total of 191 dermatology patients referred to patch testing were provided with a self-test package with written instructions. The self-test was applied on the arm by the patient, on the same day that the regular patch test was applied on the back. The patient evaluated the self-test before patch test reading at the clinic. Patch test at the dermatology clinic detected 46/191 (24%) nickel-positive individuals. The sensitivity of the self-test was 72% (95% confidence interval (CI) 57-84), the specificity 91% (95% CI 85-95), and the proportion of agreement 86% (95% CI 81-91). Thus, in the population studied, the validity of self-testing for nickel allergy was adequate.

Treatment with a barrier-strengthening moisturizer prevents relapse of hand-eczema. An open, randomized, prospective, parallel group study

Hand eczema influences the quality of life. Management strategies include the use of moisturizers. In the present study the time to relapse of eczema during treatment with a barrier-strengthening moisturizer (5% urea) was compared with no treatment (no medical or non-medicated preparations) in 53 randomized patients with successfully treated hand eczema. The median time to relapse was 20 days in the moisturizer group compared with 2 days in the no treatment group (p = 0.04). Eczema relapsed in 90% of the patients within 26 weeks. No difference in severity was noted between the groups at relapse. Dermatology Life Quality Index (DLQI) increased significantly in both groups; from 4.7 to 7.1 in the moisturizer group and from 4.1 to 7.8 in the no treatment group (p < 0.01) at the time of relapse. Hence, the application of moisturizers seems to prolong the disease-free interval in patients with controlled hand eczema. Whether the data is applic-able to moisturizers without barrier-strengthening properties remains to be elucidated.

Validity of self-reported nickel allergy

BACKGROUND

To estimate the prevalence of nickel allergy, self-reports are sometimes used in epidemiological studies. Self-reports are practical and may facilitate estimation of prevalence provided that the questions are validated.

OBJECTIVES

To investigate the validity of self-reported nickel allergy.

METHODS

Three hundred and sixty-nine women, aged 30-40 years, from the general population participated in the study. The participants answered a questionnaire before a clinical examination and patch testing. The two questions being validated were 'Are you sensitive/hypersensitive/allergic to nickel?' and 'Do you get a rash from metal buttons, jewellery or other metal items that come in direct contact with your skin?'

RESULTS

Patch test showed nickel-positive reaction in 30% of the subjects. Self-reported prevalence of nickel allergy as indicated by the two respective questions was 40% and 35%. Positive predictive values for the two questions were 59% (95% CI 50-67) and 60% (95% CI 51-69). History of childhood eczema was over-represented among women with 'false-positive' self-reported nickel allergy (P = 0.008). Self-reported hand eczema or 'high wet exposure' did not influence the validity.

CONCLUSIONS

The validity of self-reported nickel allergy is low. The questions regarding nickel allergy overestimate the true prevalence of nickel allergy.

Dermatology in public health - a model for surveillance of common skin diseases

Aims: The aim was to establish a baseline prevalence of skin conditions of public health importance in the general population and taking the validity of the questions into account. Our model is intended for future surveillance of skin conditions. Methods: The suggested questions have for the first time been used in Swedish population surveys. A random sample was taken from the general population aged 16 to 84 years of the participating areas. Results: During the past 12 months, hand eczema was reported by 9.4%, childhood eczema by 15.7% and nickel allergy by 13.7% of the population. Hand and childhood eczema questions have previously been validated. Taking the validity into account, the actual population prevalence of hand eczema (11.7%) is underestimated, and the prevalence of atopic childhood eczema (10.0%) is overestimated based on the results of the questionnaire. In addition to presenting prevalence, population survey results can be used for risk analyses. A 10-fold risk of hand eczema in individuals with childhood eczema and self-reported nickel sensitivity is shown in our study. Conclusions: Questionnaires can be used for epidemiologic surveillance so long as the questions are validated and that the validity is taken into account when estimating the occurrence of the conditions. Public health surveys such as this one lay the basis for future epidemiological surveillance of skin conditions that can be subject to interventions. We propose that these, or similar, questions should be used regularly in population surveys and supplemented by questions on skin exposure.

Hand eczema and quality of life: a population-based study

BACKGROUND

Hand eczema is a common disease in the population and is of interest from a public health perspective. Health-related quality of life (HRQoL) is increasingly being measured in dermatology.

OBJECTIVES

To investigate HRQoL in relation to hand eczema in the general population.

METHODS

In the Public Health Survey of Stockholm County Council 2006, a questionnaire was sent to 57 009 randomly selected individuals aged 18-84 years. The response rate among persons of working age (18-64 years) was 58%. The questionnaire included a validated question concerning hand eczema and a generic instrument for measurement of HRQoL, the EQ-5D.

RESULTS

The proportion of individuals reporting problems was significantly larger among those with than without hand eczema in all five dimensions of the EQ-5D. Gender differences were found in some age subgroups. The EQ-5D index was lower for individuals with hand eczema than for those without, and on the same level as for psoriasis and asthma. Beta regression showed that the strongest confounding factors were low back pain, depression and hay fever/asthma.

CONCLUSIONS

HRQoL was negatively affected in individuals with hand eczema irrespective of age. With the EQ-5D instrument it is also possible to detect certain gender differences. The EQ-5D index for hand eczema was of the same size as for psoriasis and asthma, all common diseases with an impact on public health. It is of importance to acknowledge the influence of hand eczema on daily life, in order to give the patients good care.

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.

Skin exposure in geriatric care ? a comparison between observation and self-assessment of exposure

The aim of this study was to compare observation and self-assessment of skin exposure to irritants during a working day in nursing in geriatric care. The study group consisted of 40 volunteers, 13 nurses, and 27 assistant nurses. Before the start of a working day, the participants completed a questionnaire regarding skin exposure to water, gloves, hand disinfection, and moisturizers. Observers subsequently used a hand-held computer to register the time and frequency of each exposure. The total mean skin exposure time was 96 min per working day, including glove use. The mean exposure time to water was 9 min per working day. A tendency to overestimate was found for all exposures. A strong correlation between self-reports and observations was found for hand disinfection and moisturizers, while a moderate correlation was found for gloves and number of water exposures and a weak correlation for total time of water exposure. Despite the differences between self-assessment and observation of the exposure, we consider the questionnaire to be useful for surveying skin exposure in nursing. Furthermore, the observations in this study suggest that nursing work in geriatric care may comprise limited exposure to water.

Hand Eczema Extent and Morphology – Association and Influence on Long-term Prognosis

Hand eczema extent was a strong negative prognostic factor in a previously published follow-up study of 868 individuals. The present aims were to study in the same cohort the association between the extent and the morphology of the hand eczema and to examine whether registering both improves the prediction of long-term prognosis. The cohort was divided into subgroups regarding eczema extent and morphology. An association between eczema extent and morphology was found, with a Spearman's correlation coefficient of 0.36. Thus, widespread eczema clearly tended to be polymorphic, and vice versa. More than two-thirds (68%) of the subjects with visible signs of eczema at the examination ended up in corresponding "high" or "low" subgroups according to extent and morphology. Both widespread eczema and polymorphism were negative prognostic factors, but recording morphology did not significantly add any information to the long-term prognosis for the groups with high or low extent scores. In conclusion, the results show a clear association between extent and morphology of hand eczema, both predicting prognosis. Recording morphology did not add significant information when assessing long-term prognosis. Consequently, our study indicates that preference should be given to uncomplicated assessment of eczema extent in studies on hand eczema.

Permeability of hair dye compounds p-phenylenediamine, toluene-2,5-diaminesulfate and resorcinol through protective gloves in hairdressing

Dermal exposure to skin irritants and contact allergens is frequent in hairdressing. Hair dyeing is popular today and involves exposure to highly potent contact allergens, such as p-phenylenediamine (PPD). Use of protective gloves to prevent contact with skin-damaging substances is essential. The aim of the present study was to determine the resistance to permeation by PPD, toluene-2,5-diaminesulfate (TDS) and resorcinol (RES) through protective gloves used in hairdressing in Sweden. The permeation of PPD, TDS and RES through four types of protective gloves made of natural rubber latex (NRL), polyvinylchloride (PVC), nitrile rubber (NR) and polyethene (PE) was tested using the American Society for Testing and Materials (1-inch) test cell. Exposure solutions were 5% PPD (w/v), 0.75% TDS and 10% RES in borate buffer with 0.2 M ascorbic acid. The cumulative breakthrough, the so-called 'time-lag breakthrough' (Lag-BT), and permeation rate were determined for each substance and glove. For the NRL glove, the permeated amounts were below the analytical detection levels for all the tested substances. The NR glove was permeated only by RES, with a Lag-BT of 183 min. The PE glove was the thinnest glove and had a Lag-BT of 32 min for PPD; however, the steady-state permeation rate was only 0.031 nmol cm(-2) min(-1). The PVC glove gave the lowest protection against PPD and RES. TDS did not permeate any of the tested gloves. All the tested gloves were disposable, and all need to be changed often and disposed of after use. In conclusion, if properly used, all the tested gloves give considerable protection against permeation of PPD, TDS and RES.

Remembering childhood atopic dermatitis as an adult: factors that influence recollection

BACKGROUND

Atopic dermatitis (AD) is common in the population, and studies have shown that the disease is on the increase. Studies based on hospital records reflect selected populations and may miss less severe cases of AD, and the use of self-reported questionnaires has the drawback of recall bias.

OBJECTIVES

To investigate some possible factors influencing recall bias when questionnaires are used to establish the prevalence of childhood eczema in an adult population.

METHODS

A questionnaire regarding past and present eczema was sent to 557 cases (with signs suggesting the diagnosis AD) and 554 matched controls (subjects lacking signs of AD) born during 1960-1969 and identified in school health medical records. Cases and controls were aged 31-42 years at the time of the study and 70.5% returned the questionnaire.

RESULTS

Of 403 cases, 29% did not report childhood eczema in the questionnaire. There was a difference between those who did recall their childhood AD (remembering group, RG), and those who did not (forgetful group, FG) in who had documented the diagnostic signs in the school health records. In the RG the signs were reported by both parents and school health personnel in 51% of cases, and in the FG this was true of only 16%. The RG had a higher prevalence of eczema after 15 years of age and of hand eczema. The RG also reported more visits to physicians after the age of 15 years and more time taken as sick leave due to eczema.

CONCLUSIONS

Several factors influence how well people remember their AD in childhood. These factors include disease activity in adult life, disease severity, and who noticed the eczema in childhood.

Self-reported skin exposure--validation of questions by observation

The aim of this study was to validate questions regarding skin exposure using observation. The study group consisted of 40 individuals in 5 different occupations: nurse in an intensive care unit, car mechanic, hairdresser, kitchen worker, and office worker. The participants completed a questionnaire before the start of a working day. The questionnaire covered total skin exposure times to water, foodstuffs, chemicals, and occlusive gloves and also covered the frequency of hand-washing during a working day. Observers subsequently used a hand-held computer to register the time and the frequency of each exposure. A strong correlation between self-reports and observations was found for questions regarding exposure times to water, foodstuffs, and occlusive gloves and also a moderate correlation for questions regarding frequency of hand-washing. The present observation method was insufficient for estimating total exposure times to chemicals as the true exposure time is influenced by, e.g. the use of contaminated protective gloves and the efficacy with which the chemicals were removed. The inter-observer reliability showed a very strong correlation. We consider the questions regarding skin exposure to water, foodstuffs, protective gloves, and hand-washing to be useful for future studies. The observation method seems to be reliable, useful, and easy to apply.

Is the question 'Have you had childhood eczema?' useful for assessing childhood atopic eczema in adult population surveys?

Atopic eczema (AE) is a major risk factor for hand eczema. In Scandinavian population-based studies, the occurrence of AE in childhood has often been assessed by the question 'Have you had childhood eczema?' In the present study, this question was validated. A questionnaire was sent to 600 cases with AE and 600 controls without eczema or allergic disease, identified in school medical records from the 1960s. The response rate was 70.5%, and the mean age of the respondents was 36.7 years. The specificity of the question was 70.7% and the sensitivity 89.9%. The sensitivity was higher and the specificity lower in a subgroup with current hand eczema compared with a group without hand eczema. The results showed that the question overestimated the prevalence of AE in childhood by a factor of 1.6. When used for risk assessment, the question provided a better estimate of the risk of current hand eczema as compared with the lifetime risk of hand eczema. In conclusion, the validated question overestimated prevalence of childhood AE and may overestimate AE as a risk factor for hand eczema in adult population surveys.

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.

Self-reported skin exposure -- a population-based study

The aim was to study self-reported skin exposure in individuals from the general population with or without hand eczema. In a population-based study in 1996 using postal questionnaires to 3000 individuals, 215 of 2218 (9.7%) reported hand eczema during the past 12 months. 182 (85%) of those with hand eczema and 182 without hand eczema, matched for age and sex, participated in telephone interviews in 1997 regarding exposure to skin irritants at work and in leisure time. No differences were shown in occupational exposure to water, hand washing or chemicals in individuals with or without hand eczema. Women reported more wet exposure than men at work and in leisure time. A correlation was found between occupational wet exposure and wet work at home. Persons in high-risk occupations reported more frequent exposure to skin irritants. However, 53% in high-risk occupations reported exposure to water and detergents for less than half-hour a day and 11% in low-risk occupations for more than half-hour a day. In conclusion, individuals with or without hand eczema seem to have similar exposure to skin irritants. Using job titles as a proxy for exposure gives misclassification, which may result in underestimation of the hand eczema risk.

Incidence of hand eczema in female Swedish hairdressers

OBJECTIVE

To estimate the occurrence of hand eczema in hairdressers in Sweden.

METHODS

The occurrence of hand eczema was estimated in a Swedish longitudinal retrospective cohort study including all female graduates from vocational schools for hairdressers from 1970 to 1995. A stratified sample from the general population acted as controls. A self-administered questionnaire including questions on the occurrence of hand eczema, skin atopy, working periods and number of hair treatments performed per week was sent to the participants. Incidence rate ratios (IRRs) of hand eczema were estimated.

RESULTS

The incidence rate of hand eczema in hairdressers was 23.8 cases/1000 person-years, whereas in hairdressers who were aged <25 years it was 37.1/1000 person-years. The corresponding IRR for hairdressers compared with controls was 2.5 (95% confidence interval (CI) 2.2 to 2.8), and that for younger hairdressers was 3.1 (95% CI 2.6 to 3.5). The mean age at onset of hand eczema was 21.6 years for hairdressers and 21.2 years for controls. The 1-year prevalence of hand eczema was 18.0% for hairdressers and 12.1% for controls. A large number of hair treatments involving exposure to skin irritants and sensitisers were reported. The incidence rate of hand eczema was higher among individuals with a history of childhood eczema, both for hairdressers and for controls, giving an (age-adjusted) IRR of 1.9 and 2.2, respectively. The attributable fraction of hand eczema from skin atopy was 9.6%. A synergistic effect of skin atopy and hairdressing was found on the occurrence of hand eczema. The relative excess risk due to interaction was 1.21 (95% CI 0.21 to 2.21; p = 0.01).

CONCLUSION

Hairdressers are highly exposed to skin-damaging substances. The self-reported incidence of hand eczema was substantially higher in female hairdressers than in controls from the general population and than that found previously in register-based studies. For many individuals, onset of hand eczema occurs early in life. Only about 10% of the hand eczema cases among hairdressers would be prevented if no one with skin atopy entered the trade.