Occupational Contact Dermatitis in the Food Industry

Keywords

Occupational Dermatitis; Contact Dermatitis; Nordic Occupational Skin Questionnaire; Food Industry Workers.

Introduction

Occupational dermatosis (OD) or occupational skin disease (OSD) is described as any pathological condition of the skin, which is caused or worsened by an occupational exposure [1]. Skin diseases account for more than 30% of all occupational diseases, affecting approximately 1 per 1000 workers annually and are responsible for decreased productivity and lost workdays in different industries [1]. Environmental chemicals are among the main causes of OSDs and there are about 2000 substances known as contact allergens [1]. Approximately 90% of all OSDs are reported as contact dermatitis [9, 10]. The food and catering industries account for more than 10% of all occupational dermatitis, which is considered as a major occupational health threat. The most important workers at risk include chefs, cooks, kitchen and catering assistants and counter hands. Waiters, cleaners, bakers, confectioners, greengrocers and meat, poultry and fish handlers are among other workers at risk in this area [5]. In most of the food and catering jobs, prolonged contact with water, soap and disinfectants required for hygiene issues causes more than 55% of dermatitis cases. More than 40% of occupational dermatitis in industry is due to contact with foods, including sugar, flour, fruits, vegetables, seasonings, seafood, meat and poultry [5]. Occupational dermatitis may be seen mainly as irritant contact dermatitis and allergic contact dermatitis [6]. Various host factors may have a role in developing occupational dermatitis, such as history of atopy, pigmented skins, old and wrinkled skins and immune deficient workers. White people, compared with blacks are more prone to dermatitis [7, 8]. The primary aim of this research was to investigate contact dermatitis and its related occupational factors among food handlers and sellers.

Materials And Methods

This cross-sectional study was carried out under supervision of Mashhad University of Medical Sciences form 2017 to 2018. Regular training courses are conducted in Iran for food preparers, distributers and sellers including greengrocers, butchers, bakers, confectioners and restaurant, catering and fast-food staff. Subjects referred to these training centers were studied using random sampling method within one year period. Those who had foodrelated occupations for at least one year in the city of Mashhad were included in this study and exclusion criteria were as follows: dissatisfaction for entering the study, immunocompromised cases, using immunosuppressive drugs and previous history of a skin disease before employment. A two-part questionnaire, including a demographic checklist designed by the author and the validated Nordic Occupational Skin Questionnaire (NOSQ-2002/SHORT) was used. Cases with dermatitis were examined by occupational medicine specialists and referred to our dermatologist colleague for a precise diagnosis. Data were collected and entered into the SPSS V.20 Software. The relationship between the frequency of dermatitis and job-related factors were evaluated with the T-test, chi-squared test and Fisher’s exact test. The level of significance was 0.05 for all tests.

Findings

Demographic indices A total of 384 food handlers in the city of Mashhad were studied. 316 (82.3%) cases were male and 68 (17.7%) cases were female. Among the participants, 288 (75%) cases were married and 96 (25%) were single. According to education levels, 6 were illiterate (1.6%), 340 had a high school diploma or less (88.5%) and 38 had higher education (9.9%). Among the participants of this study 32 (8.3%) cases had a pet. 32 (8.4%) subjects were suffering from eczema, 25 (78.1%) of those had hand eczema, 6 (18.8%) had both wrist and hand eczema and 1 (3.1%) had eczema confined to the wrist. Subjects with hand and/or wrist eczema were asked regarding probable factors of dermatitis in or out of the work place. Among them 4 (12.5%) cases believed that the probable factor was outside the workplace while 17 (58.6%) cases blamed workplace for developing the disease. The number of subjects suffered from itchy, dry and scaly skin were 2 (0.5%), 54 (14.1%) and 2 (0.5%), respectively. 18 (4.7%) cases reported more than one skin symptom and 308 (80.2%) cases showed no skin symptoms. 42 (10.9%) cases stated that seasonal changes altered the skin symptoms and 342 (89.1%) believed that seasonal changes had no effect on their skin. Table 1 shows the frequency of hand eczema according to the time of occurrence.

The relationship between the quantitative and qualitative demographic and occupational variables was appropriate according to the statistical tests. Table 2 illustrates the qualitative demographic and occupational variables in two groups of patients with hand eczema and healthy individuals.

Table 3 shows the frequency of occupations in both study groups. Chi-squared test was used to compare the frequency of jobs in both study groups, through which no significant difference was detected between the two groups, in terms of current jobs (P=0.49).

Moreover, table 4 depicts the quantitative demographic and job variables in two groups of patients with hand eczema and healthy individuals. The relationship between annual eczema recurrence while working and occupation types was studied based on an appropriate statistical test and no significant relationship was found (P=0.67) (Table 5).

The relationship between eczema improvement during weekends within a year and occupation types was studies and no significant relationship was detected (P=0.86) (Table 6).

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Table 1:

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Table 1. Timing of Skin Symptoms in Patients with Dermatitis.

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Table 2:

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Table 2. Evaluating the Qualitative Demographic and Occupational Variables in Two Groups of Patients with Hand Eczema and Healthy Individuals.

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Table 3:

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Table 3. Comparing the Frequency of Jobs in Both Groups of Patients with Hand Eczema and Healthy Individuals.

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Table 4:

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Table 4. Evaluating the Quantitative Demographic and Job Variables in Two Groups of Patients with Hand Eczema and Healthy Individuals.

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Table 5:

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Table 5. The Relationship between Annual Eczema Recurrence while Working and Occupation Types.

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Table 6:

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Table 6. The Relationship between Eczema Improvement during weekends within a Year and Occupation Types.

Discussion and Conclusion

Of the 345 employees working as food preparers, distributers and sellers 32 (8.4%) subjects had eczema. The annual prevalence of dermatitis was 7.5% in this study. Recent studies on occupational health indicate that food-related occupations are among the major factors contributing to contact dermatitis [2, 5]. Smith et al. reported the annual prevalence of skin disorders in food industry among kitchen workers was 1414 people per million. The study was performed on 193,132 personnel using a questionnaire. Skin disorders were higher among cases who had wet-work exposure [21]. In another study on 1052 food industry workers in Finland in 1985, Peltonen et al. showed that 17% of their study population were suffering from skin diseases. The frequency of occupational eczema was 8.5% which was twice higher among fish, meat and vegetable handlers and also confectioners. Hand eczema existed in 15% of the food handlers and 6% of the office employees [19]. Other studies reported a higher prevalence. According to a study by Sylvia Teo et al. (2003), the prevalence of occupational dermatitis among 457 restaurant, catering and fast-food staff in Singapore was 10% within a year [22]. The incidence of occupational dermatitis was reported 34% among 90 food services workers in Poland [18] and in another research the annual incidence rates of occupational dermatoses in Germany were 33.2% and 23.9% among bakers and pastry cooks, respectively [23]. In a similar study conducted in Iran by Fathi et al., the incidence of occupational dermatitis among the food industry staff was 9.5% in a 5-year period in the city of Yazd [15]. In the present study, the one-year prevalence of dermatitis among food industry workers was 7.3%. The following factors may account for the significant difference in the rate of occupational dermatitis between Iranians and other populations:

1- Genetic: Genetic effects, particularly atopic backgrounds, vary in different populations (7 and 8).

2- Risk factors for contact dermatitis: Food consumption patterns of Iran is different from other countries. For example, mustard which is a popular ingredient of salad dressings and induces contact dermatitis, is less commonly used in our country (7 and 8).

Furthermore, seafood types, meat types and spices are different from each other in East Asia, Europe and Iran. In addition, cooking traditions in some countries are different from our country.

3- Hand washing: Based on the guideline for the workplace and environmental health center, the workers of food supply, distribution and preservation units should frequently wash their hands with a particular method. Considering the significant role of soap and water in developing contact dermatitis, dermatitis types in different countries may be due to the number of hand-washing episodes per day. In this study, 77 participants (20%) reported a low frequency of daily hand-washing. In addition, despite ensuring confidentiality, honesty of workers in completing questionnaires is still doubtful.

4- Unbalanced job distribution of the subjects: In the current study, different jobs related to raw foods, food preparation and preservation and food products were assessed. Similar studies were mostly concentrated on fast-food employees, bakers and confectioners. Hence, a reason for the presence of various prevalence rates may be the diversified variable in the subcategories of industry.

5- No defined job duty: Another distribution difference may be the duty of individuals in some units, so that there are no factors related to dermatitis. For example the exposure factors would change for a cook assistant working the whole day or all days of the week.

6- Climate conditions: The amount of moisture alters the frequency of dermatitis [2]. Current study demonstrated that a personal or family history of atopy and also gender differences affected the prevalence of the contact dermatitis, highlights the role of genetics in the outbreak of dermatitis in the study population. Similar studies showed a significant relationship between the hand washing frequency, job safety and etc., and the prevalence of contact dermatitis [22]. In this study, the aforementioned factors were different between dermatitis patients and healthy subjects. Nevertheless, no statistically significant difference was detected. The reasons to explain this issue may be explained as follows:

1- The presence of recall bias in symptom improvement during the holiday period. Considering the fact that symptom improvement requires at least one week off, the employees had probably no such long holidays since Mashhad is a touristic city. 2. The presence of reporting bias in hand washing frequency and using personal protective equipment, which is less frequent considering the random sampling.

3. Short-term employment record, economic status of the country and new employments may be among other influencing factors. The number of children under 4 years was considered as a contributing factor to dermatitis but no statistically significant result was achieved in our study. This outcome could be explained as the lower percentage of females (17.7%), who are more responsible for child care in our country (24). In this article, the average employment period in dermatitis group was more than the healthy group, however, the difference was not statistically significant. This may be due to a relatively low average of working years in the study population (7 years on average) according to the employment of young persons and frequent job change in industry. The findings of this study indicate that the annual prevalence of dermatitis is higher among men, which is probably because of the job type (women mostly work as packaging staff and men work as food preparers and have direct contact with raw materials). The incidence of chronic diseases was low in the study population (probably due to a lower average age) which made the application of statistical tests difficult. The level of education had no relationship with the prevalence of dermatitis, because of the proximity of the educational levels in the study groups. Moreover, the reporting bias (inaccurate reporting of educational level) was inevitable.

Advantages

The translation and assessment of reliability and validity of Nordic skin Questionnaire was a major advantage of this study. The study sample is relatively larger than similar studies.

Disadvantages

It was not possible to assure the job relatedness of a skin disease due to the unavailability of a certain paraclinical test for food materials and high costs of testing procedures.

Suggestions

1- Developing electronic records related to the information of personnel is one of the main infrastructure actions. Considering the reasonable initial costs of launching this system as well as training people, the industrial system and related occupational diseases could be assessed more accurately. Finally, this could lessen the financial burden of insurance and corporations and also reduces the inconvenience of employees in the upcoming years.

2- Detecting patients with atopy during periodical job examinations helps to regularly track any probable skin disorder in future.