Smoking and obesity are associated with chronic hand eczema and severity of hand eczema: Data from the Dutch general population

Funding information The LifeLines Biobank initiative has been made possible by subsidy from the Dutch Ministry of Health, Welfare and Sport, the Dutch Ministry of Economic Affairs, the University Medical Center Groningen (UMCG The Netherlands), University Groningen and the Northern Provinces of The Netherlands. There was no involvement in study design, data collection, data analysis, manuscript preparation, and/or publication decisions. K E YWORD S : general population, hand dermatitis, hand eczema, lifestyle factors, obesity, smoking, stress

With an increasing focus on preventive and personalized treatment programs in medicine, lifestyle behavior also becomes an important research topic in skin diseases. Several studies reported on the association between lifestyle factors and hand eczema (HE) before, and recently the association between HE and lifestyle factors was also investigated in a large sample of the Dutch general population. 1 However, only a small subset of the previous studies included severity of HE as outcome measure, [2][3][4] and only a few of them focused specifically on chronic hand eczema (CHE). Therefore, the aim of the current study was to assess the association between lifestyle factors and HE from the same large sample of the Dutch general population, however, this time with a focus on prevalence of CHE and severity of HE.

METHODS
This cross-sectional questionnaire-based study used data from the Lifelines Cohort Study, a multi-disciplinary prospective populationbased cohort study examining the health and health-related behaviors of 169 729 persons living in the North of The Netherlands. 5 At baseline, 2006-2013, information on lifestyle factors was collected and an additional questionnaire including questions regarding HE was sent out to all adults (n = 135 950) in 2020. In total, 58 198 participants responded (42.8%) of which 57 046 were 18 years or older at baseline and were included in the present analysis. Institutional review board approval was obtained at the University Medical Center Groningen, and all participants provided informed consent.
Details on definitions and categorization of CHE and all lifestyle factors has been published before and can be found in Appendix S1;

RESULTS
Data regarding prevalence and severity of HE for the whole study population have been described previously. 6 The 1-year-prevalence of CHE in the current study population was 4.6%. In total, 7.4% of all subjects with HE in the past year reported having severe or very severe HE at worst in the past year, resulting in a 1-year prevalence of severe-to-very severe HE at worst in the past year of 0.5%. Multivariate analysis showed a positive association between being female, AD, exposure to wet activities, and CHE. In addition, smoking, especially smoking ≥8 cigarettes/day, a smoking history of ≥15 packyears, stress, overweight and obesity, and a higher waist circumference (all at baseline) were also positively associated with having CHE in the past year. Age showed a negative association with CHE in the past year. Furthermore, the highest category of physical activity at baseline showed a negative association with CHE in the past year (Table 1).
For severe-to-very severe HE in the past year, multivariate analyses showed a negative association between age and severity of HE, and a positive association between AD, exposure to wet T A B L E 1 Patient characteristics and lifestyle factors for the total study population, stratified by subjects with chronic hand eczema, subjects without hand eczema ever, and severity of hand eczema found a positive association between smoking and severity of HE and no association between stress or BMI and severity of HE. The selfadministered photographic guide was used to assess current severity. 3 These results are partly in line with the current study and conflicts might be explained by the varying study setting and methods of severity assessment and diagnosis between the studies. In addition, the current study design needs to be taken into consideration, were data from lifestyle factors was collected several years before the questionnaire regarding CHE and severity of HE was send out, which could have altered the results due to fluctuations of some lifestyle factors.
In conclusion, smoking and obesity were associated with CHE and severity of HE. Replication of these results in an independent cohort will be important to support these findings. Ideally, future  as gel nails and long-lasting nail polish, and in dental plastic fillings.
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CASE REPORT
A 61-year-old woman presented because of a one-sided facial rash that had occurred following dental plastic fillings for gingival recession.
She had no history of previous allergies, hand eczema, atopic dermatitis, and did not use any prescription medicine. She had for 28 years