A Relationship between Physical Activities and Hand Dermatitis: An Epidemiology Study of the USA Population.

BACKGROUND: Hand dermatitis is a common, chronic relapsing skin disease, resulting from a variety of causes including endogenous predisposition and environmental exposures to irritants and allergens. Physical activities have been reported to be beneficial for patients with hand dermatitis.
OBJECTIVES: We aim to evaluate the association between self-reported physical activities and hand dermatitis using the 2003-2004 National Health and Nutrition Examination Survey (NHANES) database.
METHODS: Information regarding 2,688 participants aged 20 to 59 years from the 2003-2004 NHANES cycle were retrieved and analyzed. Diagnosis of hand dermatitis was based on standardized photographs of the hands read by two dermatologists. Physical activity during leisure time for the prior 30 days was assessed using standardized questionnaire. Based on the suggested MET scores provided for each response in the questionnaire section of the NHANES methodology, the MET scores for average level of physical activities, walking/bicycling, and performing tasks around home/yard for the past 30 days was calculated.
RESULTS: There were 42 (1.56%) diagnosed cases of active hand dermatitis among the 2,688 participants. Those who reported recent vigorous or moderate physical activities were less likely to have a diagnosis of active hand dermatitis (OR: 0.436, 95% CI: 0.200 to 0.947, P = 0.036 and OR: 0.489, 95% CI: 0.261 to 0.916, P = 0.025, respectively). This negative association remained statistically significant even after adjusting for age, gender, ethnic groups and atopic diathesis.
CONCLUSIONS: Moderate and vigorous levels of physical activities appeared to be beneficial for hand dermatitis. Therefore, it is important to advise patients with active hand dermatitis to remain physically active. However, clinicians should also be cognizant of the fact that the heat and sweat generated from physical activities might also exacerbate the condition.

What was known?

Hand dermatitis is a known inflammatory condition that is associated with endogenous and exogenous factors. Lifestyle factors such as smoking and physical exercise have been implicated in mediating the course of hand dermatitis.

Introduction

Hand dermatitis is a common, chronic relapsing skin disease resulting from a variety of causes including atopic diathesis, contact with irritants/allergens, and wet works.[1234] Lifestyle factors such as physical exercise have been implicated to be negatively associated with hand dermatitis, which is an inflammatory condition of unknown mechanism.[56] Physical activity has been shown to modulate inflammatory processes by influencing granulocytes, lymphocytes, monocytes, as well as cytokines.[789] Few studies, however, evaluate the relationship between exercise and hand dermatitis. In this study, we aim to evaluate the association between physical activity and hand dermatitis using the National Health and Nutrition Examination Survey (NHANES) database.

Methods

Study population

NHANES is a periodic, annual population survey that targets the civilian, noninstitutionalized USA population. It utilizes a stratified multistage probability sampling design. In our analysis of interest, randomly selected individuals aged 20–59 years are interviewed in their homes about the below-mentioned variables of interest. A total of 2688 participants subsequently completed health examinations. Data on hand dermatitis diagnosis, and information on physical activity during leisure time in the cycle year 2003–2004 were retrieved and analyzed.

Outcome

Diagnoses of active hand dermatitis were identified from the 2003 to 2004 NHANES examination data. All study participants had standardized photographs of dorsal and palmar views of the hands. These photographs were read by two dermatologists for the presence of hand dermatitis. When the findings of the two dermatologists disagreed, the image reading software program required a third consensus reading. For the consensus readings, both dermatologists reviewed the image simultaneously and came to a unified decision.

Exposure

Physical activity during leisure time for the past 30 days was assessed using questionnaire data in NHANES. The participants were asked the following questions to determine their level of physical activity, frequency, as well as the duration of each exertion. The participants were asked if they were doing any vigorous activities for at least 10 min that caused heavy sweating or a significant increase in breathing or heart rate. Examples of these activities included running, lap swimming, aerobics classes, or fast bicycling. Similarly, they were asked if they did any moderate activities for at least 10 min that cause only light sweating or a slight to moderate increase in breathing or heart rate. Examples of such activities included brisk walking, bicycling for pleasure, or dancing. They were also asked to rate their average level of physical activity each day by choosing one of the following four descriptions of their usual daily activities: (1) Sits during the day and does not walk about very much, (2) stand or walk about a lot during the day but does not have to carry or lift things very often, (3) lift light load or has to climb stairs or hills often, and (4) do heavy work or carries heavy loads. Since the frequency of the activities and the time spent during each session were provided, the total time spent in walking/bicycling for the past 30 days could be determined. Based on the suggested metabolic equivalent (MET) scores provided for each response in the questionnaire section of the NHANES methodology, separate MET scores for average level of physical activities and walking/bicycling for the past 30 days were calculated.

Questionnaire data variables

Demographic variables such as age, gender, and ethnic groups were included for analysis as possible confounding factors.

Ethnic groups were categorized as “Mexican American,” “other Hispanic,” “non-Hispanic white,” “non-Hispanic black,” and “other race.” As there were no direct questions about any personal history of atopic diatheses, a positive response to any one of the following: a personal or family history of asthma or a recent history of hay fever was assigned a positive history of atopic diathesis.

Data analysis

The analysis of the association between hand dermatitis and physical activity during the leisure time was done using Chi-square or Fisher exact tests. Using two sample t-test and Mann–Whitney U-test, the total amount of time spent in walking/bicycling and performing tasks around home/yard were compared between those with and without hand dermatitis. In order to examine the potential confounding effect of selected variables, we performed multivariate logistic regression with hand dermatitis as the dependent variable and aforementioned confounding factors as the independent variables.

The statistical package for social sciences (IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp.) was utilized to perform the analysis. Odds ratio (OR), 95% OR confidence interval (CI), and P values were calculated to test the null hypotheses of the association between physical activities with a diagnosis of hand dermatitis.

Clinical information and questionnaire data of the 2003–2004 NHANES cycle were available from the publicly accessible U.S. Centers for Disease Control and Prevention database. The NHANES was approved by the Institutional U.S. National Center for Health Statistics Ethics Review Board and documented consent was obtained from participants.

Results

A total of 2688 participants were included in the analysis. There were 42 (1.56%) diagnosed cases of active hand dermatitis. Among cases of active hand dermatitis, there was a strong male predominance (90.5%). Those who were diagnosed with active hand dermatitis had a slightly older mean age, compared to those who did not, however, this did not reach statistical significance (P = 0.129). Other characteristics of patients with and without hand dermatitis are summarized in Table 1.

Table 1

Characteristics of patients with and without hand dermatitis

The participants who reported moderate and vigorous physical activities for at least 10 min for the past 30 days were less likely to have a diagnosis of active hand dermatitis (OR: 0.489, 95% CI: 0.261–0.916, P = 0.025 and OR: 0.436, 95% CI: 0.200–0.947, P = 0.036, respectively). However, those who described their average daily activities as doing heavy work or carrying heavy loads were more likely to have active hand dermatitis, compared to those who reported sitting around and not walking about (OR 4.351, 95% CI: 1.473–12.857, P = 0.008). The mean MET scores for average daily activities were also significantly higher in participants with active hand dermatitis. The amount of time spent in walking/bicycling did not differ significantly between those with and without active hand dermatitis. The mean MET scores for walking/bicycling also did not differ significantly between the two groups.

To adjust for possible confounding factors such as age, gender, ethnic groups, and atopic diathesis; multivariate logistic regression was performed. The negative association between recent moderate or vigorous physical activities and active hand dermatitis remained statistically significant even after adjusting for the aforementioned confounders (adjusted OR: 0.515, P = 0.043 and adjusted OR: 0.396, P = 0.011, respectively). The significant association between level of average daily activities and hand dermatitis, however, became attenuated after adjusting for confounders. The results of adjusted ORs from the logistic regression models are summarized in Table 2.

Table 2

Univariate and multivariate logistic regression of physical activity with hand dermatitis

Discussion

In this study, the risk of having active hand dermatitis was significantly lower in participants who reported moderate or vigorous physical activities in the past 30 days. The activities examined in NHANES database mostly involved aerobic exercises and typically would not cause friction over the hands. The beneficial effects of physical activities on hand dermatitis have been documented in various epidemiological studies.[12310] A study by Wrangsjö et al. suggested that physical exercise was associated with a lower prevalence of hand eczema.[11] A Sweden study similarly reported that the prevalence of hand eczema was lower in individuals with high levels of physical exercise.[10] The physical exercise has been postulated to promote muscle fibers’ production of interleukin-6 (IL-6), which stimulates the production of anti-inflammatory cytokines, such as IL-1 receptor antagonist and IL-10, and inhibits the production of pro-inflammatory cytokines like tumor necrosis factor-α (TNF-α).[12] Alterations in cytokines such as IL-1, IL-2, IL-8, IL-10, and TNF-α were suggested to be responsible for the pathogenesis of hand dermatitis.[10] Therefore, it is likely that physical exercise influences hand dermatitis through the modulation of inflammatory cytokines.

Though physicians’ assessment of standardized photographs is a very specific screening method, it may be less sensitive to detect cases of hand dermatitis that were mild or relapsing infrequently. Instead of identifying past diagnoses of hand dermatitis, the photographs would likely reflect a more current condition of the hands. Therefore, the cases of hand dermatitis identified in this study likely represented a more severe and persistent form. Although study participants who were engaged in heavy work or carried heavy loads were more likely to have active hand dermatitis, compared to those who have sedentary lifestyles, this relationship was attenuated after adjusting for confounding factors. However, it is also conceivable that participants who used their hands to carry heavy loads as part of their usual daily activity were more likely to have hand dermatitis because of the mechanical stress and friction involved in these activities, despite a beneficial effect of physical activities on hand dermatitis. The total amount of time spent and means MET scores were calculated in order to evaluate a potential dose-response relationship between physical activity and hand dermatitis. In our analysis, however, the amount of time spent and mean MET scores for walking/bicycling did not differ significantly between those with or without hand dermatitis. In contrast, Anveden Berglind et al. demonstrated a significant negative dose-response relationship between hand dermatitis and physical exercise in men.[10] More research would be needed to further explore this relationship.

One of the strengths of this study is the specific screening method for hand dermatitis among a representative general population. The diagnosis of hand dermatitis was made from standardized photographs by at least one dermatologist. However, there was no information on the type of hand dermatitis and the duration of the condition for each case. Given that the more severe and persistent forms of hand dermatitis were identified, the results of this study may be more generalizable to those with more chronic and occupation-related hand dermatitis. Given the cross-sectional nature of this study, it was not possible to establish any causal relationship between physical activity and hand dermatitis. There might be reverse causation such that participants with significant hand dermatitis avoid performing physical activities. The participants were also asked to self-report their recent physical activities for the past 30 days. This can lead to recall bias and potential over- or under-reporting of their physical activities. Other possible confounding variables like contact allergies, and the habits of frequent hand washing were also not available in the database.

Conclusion

Moderate and vigorous levels of physical activities had significant negative associations with hand dermatitis. However, those with severe and persistent forms of hand dermatitis may be more likely to avoid physical exercise due to pain or sweating. An observational longitudinal cohort study with objective assessments of physical activity and hand dermatitis severity would be useful to evaluate a possible dose-dependent association. It is important to advise patients with active hand dermatitis to remain physically active while being cognizant of the fact that resulting heat and sweat can also exacerbate the condition.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

What is new?

Moderate and vigorous physical activities may be beneficial for hand dermatitis. However, the patients with severe hand dermatitis may avoid physical activities due to pain or sweating.