Do lifestyle factors influence the occurrence of hand eczema?

Keywords::

• alcohol consumption
• dose–response relationship
• epidemiology
• obesity
• physical exercise
• smoking
• stress

Hand eczema is a common skin disease with a 1-year prevalence of 10% in the Swedish population of working age [1]. Many factors are known to contribute to the onset of hand eczema, and also to the chronic course observed in many patients [2,3]. Well-known risk factors for hand eczema are endogenous factors such as skin atopy [4,5], and exogenous factors such as exposure to skin irritants and contact allergens [6]. Women are more often affected than men and the prevalence of hand eczema is highest among young adults [1]. The gender and age differences are considered to be mainly related to skin exposure. Women and people with entry-level jobs are more frequently occupationally exposed to wet conditions. Nonoccupational wet exposure is also an important factor to consider, particularly since the extent of such exposure is substantial [7].

Growing interest has lately been focused on the influence of lifestyle factors such as alcohol consumption, smoking, eating habits, stress and physical exercise on many health conditions. Such a relationship should also be considered in the context of skin diseases. The relationship between tobacco smoking and hand eczema has been investigated in a number of studies but the results have not been consistent. In about half of the published studies, a positive relation between smoking and hand eczema was found [5,8–11], while in the rest of the studies no such relation was shown [12–14]. In a previous study our group found an association between hand eczema and smoking in a subgroup that included female hairdressers, who smoked more than ten cigarettes per day, although the results when analyzing smokers versus nonsmokers in total were negative [15]. This made us consider the possibility of a dose–response relationship for the association between hand eczema and smoking.

In a later population-based study we examined a possible association between occurrence of hand eczema and tobacco smoking, with the focus on a possible dose–response relationship [16]. Self-reported data from a national environmental health survey in a random sample from the general population of Sweden was used. More than 25,000 individuals had responded to the questionnaire items regarding hand eczema and smoking at different intensity levels. A simple comparison of daily smokers versus nonsmokers did not reveal any statistically significant difference in 1-year prevalence of hand eczema (p = 0.095). Multivariate analysis considering potential confounders revealed a moderately increased risk of hand eczema among heavy smokers (more than 15 cigarettes per day; prevalence proportion ratio [PPR]: 1.40; 95% CI: 1.15–1.71). A dose–response relationship between level of smoking and 1-year prevalence of hand eczema could be shown, with a PPR of 1.05 (p < 0.001) for the continuous variable of smoking habits, indicating an increased prevalence of hand eczema among individuals with higher consumption of tobacco. It appears that more is required than just smoking a few cigarettes if the harmful effect is to be detectable. This is the probable reason why some of the previous studies could not identify an association between smoking and hand eczema. Thus, it is crucial to perform careful data analyses considering both levels of exposure and potential confounders to obtain informative results.

Are there additional lifestyle factors that might have a relationship with hand eczema and that should be taken into consideration? In a recent paper from our research group, a possible association between several different lifestyle factors and hand eczema was studied [17]. In a public health survey in Stockholm, Sweden, almost 28,000 randomly selected individuals answered a postal questionnaire regarding physical and mental health, social relations, economic status and work. The association between hand eczema and lifestyle factors such as obesity, physical exercise, stress, smoking and alcohol consumption was analyzed by PPRs using a generalized linear model. In a multivariate analysis adjusted for confounders (neck/shoulder pain, low-back pain, depression, occupational water exposure, reduced well-being and job strain) hand eczema was found to be more common in individuals who reported stress (PPR: 1.33; 95% CI: 1.30–1.35), in individuals with obesity (BMI exceeding 30; PPR: 1.20; 95% CI: 1.17–1.23) and in daily smokers (PPR: 1.03; 95% CI: 1.01–1.04). In individuals who reported high physical exercise levels hand eczema was less common (PPR: 0.78; 95% CI: 0.77–0.79). For alcohol consumption, the effect was marginal. Thus, these results strongly indicate an association between hand eczema and lifestyle factors.

The population surveys that generated data for these two studies have a cross-sectional design [16,17]. Thus, data regarding exposure and disease are collected at a certain point in time. This precludes drawing any conclusions regarding the causal relationship between lifestyle factors and hand eczema. Nonetheless, the results are interesting and prompt us to think along new lines and perhaps generate new hypotheses. Mechanisms underlying the observed associations between the lifestyle factors and hand eczema cannot be investigated in these types of studies but it is undoubtedly of great interest to investigate them. Stress is known to result in physiological changes, for example in the skin barrier, that might lead to eczema [18]. Tobacco smoking is a well-known risk factor for developing several other dermatological inflammatory diseases [19–21]. A possible influence of obesity on hand eczema has not been previously studied; nor has the immune response in patients with hand eczema during exercise, but an alteration of the inflammatory response is possible.

Questionnaire-based public health surveys have been performed regularly in Sweden since the 1970s. These surveys provide valuable data for epidemiological surveillance of several health conditions and exposures. The occurrence of common skin diseases and potential risk factors can also be followed up by such surveys [5]. Most of the questions regarding the lifestyle factors presented here have also been used in previous health surveys and have been found to be useful. The question regarding hand eczema “Have you during the past 12 months had hand eczema on some occasion?” has previously been validated [22] and the validity of questions on smoking habits have been evaluated [23]. Epidemiology seems to be a valuable source of new knowledge, provided that the methods are used judiciously.

To be able to offer patients with hand eczema good care it is important to consider their total life situation. It appears not to be enough just to focus on the traditional risk factors for hand eczema, such as skin irritation and contact allergy, one must also consider several lifestyle factors.

Financial & competing interests disclosure

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.