Water, soap, and hand‐disinfectant exposure during the COVID‐19 pandemic and self‐reported hand eczema in frontline workers: A cross‐sectional study

During the COVID‐19 pandemic, increased hand hygiene practices were implemented. Impaired skin health on the hands among healthcare workers has been reported previously. Knowledge of how worker in other occupations have been affected is scarce.

2][13][14][15][16] The studies show enhanced usage of personal protective equipment, such as gloves and face masks, and increased hand hygiene procedures leading to an increase in eczema.A Swedish study, performed within the healthcare sector, reported an association between both washing hands with soap more than 20 times/day and wearing gloves for more than 3 h daily with hand eczema. 13Furthermore, the study showed that the point prevalence of self-reported HE was 14%, which is in line with a German study where the selfreported point prevalence was 15% among HCWs. 12,13Although most of the published studies have focused on HCWs, several other frontline workers have been in close contact with other people during the COVID-19 pandemic.A newly published study from Norway, 16 reports that increased frequencies in hand washing, use of hand disinfectants, and gloves were associated with an increase in skin symptoms on hand, wrists, and forearms among HCWs, hospital cleaners, and day-care workers.
To study frontline workers, not working within primary health care, we conducted a questionnaire-based cross-sectional study among six occupational groups.The aim of the study was to investigate self-reported HE and to characterise skin exposure to water, soap, and use of hand disinfectants before and during the first year of the COVID-19 pandemic in Sweden.

| METHODS
The study was approved by the Swedish Ethical Review Authority (NO.2020-06684).The questionnaire comprised 52 questions covering the following subjects: • Demographic background information: employment status and time (%) spent at workplace.
• Exposure patterns: frequency contact with water, soap, and hand disinfectant (HD) per day both at the workplace and at home.
• Skin symptoms: prevalence and development of HE.
• Medication, medical assistance, and sick leave: usage of corticoid steroids, contact with medical doctors, and sick leave duration.
Questions regarding HE and water exposure to the hands have previously been validated and were modified to be appropriate during the COVID-19 pandemic. 8,17,18In our current study "during the pandemic" lasts around 12 months (from March 2020 to March-April 2021).Exposure was reported using the following frequency groups: 0, 1-10, 11-20, 21-30, and more than 30 (Supporting Information Table S1).For convenience, the two highest response intervals (21-30 and more than 30) are here represented as >20.In addition to the variables collected via the questionnaire, the following register variables were retrieved: sex, birth year, occupation, education level, and region of birth.

| Statistical analysis
RStudio software was used for chi-square tests and bubble chart illustrations (version 2022.07.2.576).GraphPad Prism (version 9.0) was used to generate the graphics of hand exposure to water and disinfectant.
Chi-square tests were performed for group comparisons and a p-value <0.05 was considered to be statistically significant.The Svensson's statistical method was used to analyse differences on water-and hand-disinfectant exposure before and during the COVID-19 pandemic. 19,20This statistical method can be used to identify and measure systematic disagreements in paired ordinal data.The degree of systematic change is expressed as the relative position (RP), a non-zero RP indicates a systematic change between the paired rank assessments.An RP whose 95 percent confidence interval (95% CI) does not include zero was considered to be a statistically significant change.

| RESULTS
The overall response rate was 24.3% in the study (Table 1).Respondents were between 20 and 67 years (mean age 45.9 years, SD 12.5) at the time of questionnaire distribution.Slightly more than half (51.2%) were women.Frontline workers represented 69.1% (mean age 46.3 years, SD 13.2) and IT personnel 30.9% (mean age 45.1 years, SD 10.7) of the study population.Time spent at work or at home is presented in Table S2, supporting information.Overall, the frontline workers remained at the workplace, whereas most of the IT personnel worked from home during the COVID-19 pandemic.

| Self-reported prevalence of hand eczema and treatment
In the total population, 33% of respondents reported to have had HE at least once before the COVID-19 pandemic started and 21% reported having HE during the pandemic (Table 2).When stratifying by occupational group, frontline workers reported a significantly higher frequency of HE during the COVID-19 pandemic compared to IT personnel (23% and 15%, respectively; Chi-square p <0.001).Furthermore, frontline workers also reported newly debuted HE to a larger extent than IT personnel (8.6% and 4.9%, respectively; chisquare, p = 0.012).Newly debuted HE was reported by 7.4% of the population and a relapse of the HE during the pandemic was reported by 6.9%.
Among those with HE during the pandemic (n = 304), 41.5% reported topical treatment with corticosteroid, and medical care because of HE was sought by 9.9%.Sick leave because of HE was taken by 1.6%.

| Water and soap exposures per day and use of hand disinfectant
Water exposure and use of HD increased for the entire study population during the COVID-19 pandemic (Figure 1) compared to before the pandemic.This change was statistically significant for water (RP 0.19; 95% confidence interval (CI) 0.17-0.21)and for HD (RP = 0.38: 95% CI 0.36-0.41).

| Exposure pattern stratified by occupational group
The number of water and soap exposures and HD per workday is presented for both frontline workers and IT personnel in Figure 2.During the COVID-19 pandemic, 35% of the frontline workers and 8.5% of the IT personnel reported water exposure more than 20 times per day.The corresponding numbers before the COVID-19 pandemic was 22% and 2.2%, respectively.Furthermore, a concordance was displayed between water and soap exposures for all the respondents (Figure S1, Supporting Information).
Similarly, using HD more than 20 times per day, was more frequently reported among frontline workers than IT personnel, both before (13% and 0.6%, respectively) and during the COVID-19 pandemic (26% and 1.9%, respectively), Figure 2.
Increased water and soap exposures and use of HD were also shown in the home environment (Supporting information Figure S2).
Change in water exposure for the six different occupational groups is presented in Supporting information Table S3.

| Exposure pattern stratified by hand eczema status
When stratified according to self-reported HE status, increases during the COVID-19 pandemic were seen for water, soap, and use of HD per workday (Figure 3).For those who reported no HE before or during the pandemic, the proportion reporting water exposure more than 20 times per day increased from 16% to 25%.For those with newly debuted HE during the COVID-19 pandemic, the corresponding figures were 21% to 44% (Figure 3).Respondents with relapse HE, reported an increase, from 24% to 43% (Figure 3).
Water exposure and use of HD for all three groups (never HE, newly debuted HE, and relapse HE) in the home environment is presented in Figure S3, Supporting Information.

| DISCUSSION
In the present study, frontline workers (outside the hospital setting) and IT personnel (working mostly from home) were surveyed with regards to self-reported water-, and soap exposures and use of HD per workday, as well as prevalence of self-reported HE.A main finding of the study is the increase in reported water exposure and HD usage T A B L E 1 Description of the study population.Response rate calculated from the number of respondents per occupational group who received the questionnaire (n = 1010).Numbers of respondents (n), response rate (%), sex (%), and age (years).per workday during the COVID-19 pandemic.In our study exposure to soap correlates closely to the water exposures, hence water exposures as reported herein could be classified as hand washing, which is a strong risk factor of HE. 4 Our results show that respondents with HE during the COVID-19 pandemic, compared with those without HE, more frequently reported above 20 hand washes per day during the pandemic.Other research has shown that already 8 to 10 hand washes per day substantially increase the risk for HE, 5 which further emphasises that the increase in hand hygiene behaviour during the COVID-19 pandemic poses a risk for HE.There is no cut-off value for the causal relationship between water/soap exposure and development of HE, however, wet exposure more than 20 times per day has become commonly used as an arbitrary level to estimate the risk of developing HE. 8,17,18The wet-dry cycle, that is, frequency of exposure may be more important than duration of water exposure. 21There was also a statistically significant increase in HD use across the full study population, comparing before and during the COVID-19 pandemic.Although not as harmful as exposure to water and soap, it still indicates an additional strain on the skin.HD is regarded as an independent skin irritant, causing lipid depletion of the skin barrier mainly through reduction of natural moisturising factors.Alcohol-based hand disinfection, such as isopropyl alcohol or n-propanol (60%-90%) are less irritant on the skin compared to soap and detergents, especially when an emollient is added. 22,23Furthermore, during the pandemic, there was a lack of alcohol-based products 24 and in our clinical experience, HD products containing substances with an inherent ability to irritate the skin barrier such as sodium hypochlorite, hydrogen peroxide, and chlorohexidine gluconate had been used by patients seeking medical care for skin problems.
In our study, we observed that the water exposure significantly increased for both IT personnel, mainly working from home, and for frontline workers.However, the frontline workers already had a F I G U R E 1 Water exposure and use of hand disinfectant (times per day) before-and during the first year of the COVID-19 pandemic for the total population.The flow distribution describes how the respondents changed their behaviour during the first year of the pandemic.The change is statistically significant when tested with the Svensson's method. 19,20he pandemic, hence there are no data to compare with.Nevertheless, the increased exposures reported by respondents in this study point towards an increased risk for skin issues also for occupations beyond HCWs.
An important finding is that 7.4% of the surveyed population reported a newly debuted HE during the COVID-19 pandemic.Frontline workers were more affected by having newly debuted HE during the pandemic than the IT personnel.Relapse as well as continuous HE were also more common among the frontline workers.2][13] Hamnerius et al. studied wetwork exposure and HE among HCWs in Sweden, and saw an increase from 21% to 29% for 1-year prevalence of self-reported HE 13,25 during the pandemic.Similarly, in HCWs from Turkey, examined by a dermatologist, the prevalence of HE was 30%. 11Another study from Germany found that 15% of HCWs reported HE, although the authors suggest the actual point-prevalence HE percentage to be higher, as 90% stated to have symptoms associated with acute hand dermatitis. 12Taken together, this shows that frontline workers both within and outside of the healthcare sector have developed HE during the COVID-19 pandemic and that it is likely due to the increased hand hygiene procedures implemented to minimise the spread of the SARS-CoV2 virus.Furthermore, our study also shows that workers who spent more than 80% of their time working from home also reported having HE.
The current state of knowledge shows the importance of providing recommendations for protection of the skin barrier when increased hand hygiene behaviour is called for in future situations such as the COVID-19 pandemic.The strain from hand hygiene practices and wet work can be prevented in different ways.[28] Furthermore, moisturisers should be used regularly after use of soap and water as a preventive measure to hand dermatitis. 9,27,29though skin protection programmes and guidelines for the prevention of HE have been in place for over a decade, 2 moisturisers are frequently used as a therapeutic rather than as a preventive measure. 2,11,30limitation of the present study is the low response rate (24.3%) which limits the ability to study the behaviour differences of each occupational group.Additionally, when interpreting the results regarding risk or increase of self-reported hand eczema, it is important to bear in mind that the present study design is cross-sectional, with unadjusted data.Hence, HE prevalence could have been affected by different factors.First, there is a likelihood of subjects with skin concerns participating in this study rather than those without, causing an  S4).Given the relatively small sample sizes, it is difficult to evaluate these factors.Furthermore, although previously validated questions were used when possible, self-reported data are subject to uncertainties, and thus must always be interpreted with caution, since participants may overestimate their exposure.

From
the total population of Stockholm County council, The Swedish Occupational Register with Statistics, 2018, and the Register of Total Population, updated 30-11-2020, individuals who worked in one of the following six occupations: bus drivers, shop assistants, home care assistants, preschool teachers, cleaners, and IT personnel were identified.The five first occupational groups were selected as being frontline occupations, requiring work from outside of the employees' homes in direct contact with other people outside of the immediate family.The group of IT personnel was included as a group that could largely work from home during the pandemic.To identify occupations, the Standard for Swedish occupational Classification (SSYK, 2012) was used, which corresponds to the International Standard Classification of Occupations 2008.From the eligible population of 130,836 individuals a random sample of 6060 individuals was drawn by Statistics Sweden (SCB).
The questionnaire was distributed by Statistics Sweden, which sent out information and access to the electronic questionnaire by post in March 2021.Reminders were sent to those who had not yet answered on 23 March and 6 April.The data collection closed on 30 April 2021.
higher water exposure of the hands before the pandemic.Indeed, cleaners, preschool personnel, and home care assistants are considered wet-work occupations, while little is known about the bus drivers' and daily goods workers' water exposure before the pandemic.There also is very limited information on how these wet-work occupations have changed their water exposure of the hands during T A B L E 2 Prevalence of self-reported ever having hand eczema (HE ever) and during the COVID-19 pandemic among frontline workers and IT personnel.: Yes/No.b Pearson's Chi-squared statistical test comparing frontline workers and IT personnel, p-value for HE during COVID-19 versus not HE during COVID-19 <0.001, p-value for Yes Debutant versus remaining = 0.012.c Percentage calculated from the total population N = 1470.

F I G U R E 2
Number of water and soap exposure and use of hand disinfectant at work (times/day) for the frontline workers (top row) and IT personnel (bottom row).White bars: before the COVID-19 pandemic; Grey bars: during the COVID-19 pandemic.overestimation of HE across both investigated groups.The difference among the response rate of Frontline workers (20.1%) and IT personnel (45.0%) together with the sex distribution between the two groups could have affected the results.It is well known that women have a higher prevalence of HE, and in our sample frontline workers have a larger share of women than IT workers.However, in contrast, a history of atopic dermatitis in childhood is more frequent among IT workers (Supporting information Table

5 |
CONCLUSIONDuring the COVID-19 pandemic, self-reported exposures to water, soap, and usage of hand disinfectants increased in frontline workers and IT personnel.In the present study, 21% of all respondents (23% of frontline workers and 15% of IT personnel) reported having HE during the pandemic.Furthermore, 7.4% of the respondents reported having newly debuted HE during the pandemic.This together with the increased exposure to irritants during the COVID-19 pandemic, highlights the importance of introducing preventive measures for protecting the skin, also in other occupations than HCWs.We propose that more attention is paid to communication and implementation of preventive measures in a future pandemic situation.F I G U R E 3 Number of water and soap exposure and use of hand disinfectant at work (times/day) stratified for HE status; top row: never had hand eczema, middle row: newly debuted hand eczema during the COVID-19 pandemic; bottom row: relapse of hand eczema during the COVID-19 pandemic.White bars: before the COVID-19 pandemic; Grey bars: during the COVID-19 pandemic.[Correction added on 27 May 2024, after first online publication: In Figure 3, the label on third graph was misspelled and has been corrected to 'Hand disinfectant use'.]