Dermatitis

Background

What is dermatitis?

Contact dermatitis is a common work-related disease. It is an itchy or painful inflammatory skin reaction that looks like a rash or burn. It can present in mild forms, such as dryness with reddening, chapping and scaling, as well as in more severe forms, such as eczema-like dermatitis with swelling, blisters or fissures. It typically affects the hands, making it painful to continue work.

The Centre for Research Expertise in Occupational Disease (CREOD) reports that only 62% of contact dermatitis patients at their occupational disease clinic in Toronto returned to work 6 months after skin assessment. Of those who had returned to work, about one-third had changed jobs due to their skin problem.

 

Occupational Risk Factors
    • Wet work (work that requires extensive hand washing, immersing the hands in water or wearing gloves for extended periods of time)
    • Certain cleaning agents (soaps, shampoo, detergents)
    • Organic solvents
    • Chronic mechanical and frictional stress
    • Metalworking fluids
    • Rubber additives
    • Acids and alkalis
Key Findings

The greatest risks of contact dermatitis are observed among workers with exposure to wet work, cleaning agents, metal-working fluids, and chronic skin trauma.

Occupations associated with wet work and cleaning agents

Wet work is the main risk factor for occupational contact dermatitis and includes activities involving hand washing more than 20 times per shift, immersing hands in liquid for more than 2 hours per shift or wearing waterproof gloves. Prolonged exposure to wet work disrupts the natural barrier in the skin, so sensitizing agents can pass through the skin more easily and cause skin allergies.

Hairdressers and workers in food and beverage industries and other personal service occupations, such as laundering and cleaning, are particularly vulnerable to developing dermatitis because they are constantly exposed to both wet work and chemicals (e.g. soaps, shampoos, hair dye, cleaning agents). Food-handlers, including chefs, cooks, dishwashers and wait-staff, are legally required to wash their hands frequently and may wear gloves to prevent the spread of foodborne illness. They also clean kitchen surfaces, ovens, and dishes using various cleaning agents and detergents that could increase the risk of contact dermatitis.

    • Barbers and hairdressers: 1.5 times the risk
    • Food and beverage related occupations: 1.1 times the risk
    • Personal services: 1.1 times the risk
Occupations associated with chronic mechanical and frictional trauma and metal-working fluids

Increased risks of contact dermatitis are observed among machinists, workers in furniture and fixture industries and metal machining occupations. This may be due to chronic mechanical and frictional stress and exposure to chemicals such as metal working fluids within these occupations and industries.

Excessive friction and superficial skin injuries (i.e., abrasions, pressure, stretching, compression and cutting) damages the skin barrier. This allows allergens and irritants to pass through the skin more easily, increasing the risk of contact dermatitis. Metal-working fluids are used to lubricate metal during processes such as machining, grinding or cutting. Both frictional trauma and exposure to metal-working fluids are common in the manufacturing industry, specifically in metal machining occupations, increasing the risk of contact dermatitis among these workers.

    • Machinists: 1.3 times the risk
    • Metal machining: 1.3 times the risk
    • Furniture and fixture industry workers: 1.2 times the risk
Relative Risk by Industry and Occupation

Figure 1. Risk of dermatitis diagnosis among workers employed in each industry group relative to all others, Occupational Disease Surveillance System (ODSS), 1999-2016

The hazard ratio is an estimate of the average time to diagnosis among workers in each industry/occupation group divided by that in all others during the study period. Hazard ratios above 1.00 indicate a greater risk of disease in a given group compared to all others. Estimates are adjusted for birth year and sex. The width of the 95% Confidence Interval (CI) is based on the number of cases in each group (more cases narrows the interval).

 

Figure 2. Risk of dermatitis diagnosis among workers employed in each occupation group relative to all others, Occupational Disease Surveillance System (ODSS), 1999-2016 

The hazard ratio is an estimate of the average time to diagnosis among workers in each industry/occupation group divided by that in all others during the study period. Hazard ratios above 1.00 indicate a greater risk of disease in a given group compared to all others. Estimates are adjusted for birth year and sex. The width of the 95% Confidence Interval (CI) is based on the number of cases in each group (more cases narrows the interval).

Table of Results

Table 1. Surveillance of Dermatitis: Number of cases, workers employed, and hazard ratios in each industry (SIC)

SIC Code * Industry Group Number of cases Number of workers employed Hazard Ratio (95% CI) †
1 Agriculture 214 7,686 0.76 (0.67, 0.87)
2/3 Forestry, Fishing and Trapping 33 1,333 0.72 (0.51, 1.02)
4 Mines, Quarries and Oil Wells 80 2,938 0.81 (0.65, 1.01)
5 Manufacturing 4,254 106,619 1.11 (1.07, 1.14)
6 Construction 1,315 49,098 0.78 (0.74, 0.83)
7 Transportation, Communication and Other Utilities 1,621 46,208 0.96 (0.92, 1.01)
8 Trade 3,878 105,536 0.95 (0.92, 0.99)
9 Finance, Insurance and Real Estate 188 5,194 0.91 (0.79, 1.05)
10 Community, Business and Personal Service 7,311 170,758 1.02 (0.99, 1.05)
11 Public Administration and Defense 1,821 45,567 1.00 (0.96, 1.05)
         
* SIC: Standard Industrial Classification (1970)    
† Hazard ratio in each group relative to all others    

 

Table 2. Surveillance of Dermatitis: Number of cases, workers employed, and hazard ratios in each occupation (CCDO) group

CCDO Code * Occupation Group Number of cases Number of workers employed Hazard Ratio (95% CI) †
11 Managerial, administrative and related 498 11,973 0.98 (0.89, 1.07)
21 Natural sciences, engineering and mathematics 283 7,203 1.06 (0.94, 1.19)
23 Social sciences and related fields 532 10,389 1.13 (1.04, 1.23)
25 Religion <5 43
27 Teaching and related 888 17,718 1.09 (1.02, 1.17)
31 Medicine and health 1,731 40,325 0.90 (0.85, 0.94)
33 Artistic, literary, recreational and related 241 5,215 1.17 (1.03, 1.33)
41 Clerical and related 1,999 45,733 1.04 (0.99, 1.09)
51 Sales 1,862 46,968 0.96 (0.92, 1.01)
61 Service 3,852 91,788 1.03 (1.00, 1.07)
71 Farming, horticultural and animal husbandry 350 11,817 0.81 (0.73, 0.91)
73 Fishing, hunting, trapping and related 10 168 1.03 (0.46, 2.29)
75 Forestry and logging 33 1,110 0.87 (0.61, 1.22)
77 Mining and quarrying, including oil and gas field 50 1,818 0.82 (0.62, 1.09)
81 Processing (mineral, metal, chemical) 514 13,255 1.05 (0.96, 1.14)
82 Processing (food, wood, textile) 831 19,613 1.09 (1.02, 1.17)
83 Machining and related 1,143 29,146 1.14 (1.07, 1.21)
85 Product fabricating, assembling and repairing 2,075 53,765 1.08 (1.03, 1.13)
87 Construction trades 1,318 47,847 0.81 (0.77, 0.86)
91 Transport equipment operating 1,286 38,990 0.94 (0.89, 1.00)
93 Materials handling and related, not elsewhere classified 890 24,050 1.04 (0.97, 1.11)
95 Other crafts and equipment operating 154 3,481 1.20 (1.03, 1.41)
99 Other occupations not elsewhere classified 1,263 34,642 1.01 (0.95, 1.07)
         
* CCDO: Canadian Classification Dictionary of Occupations (1971)  
† Hazard ratio in each group relative to all others    

 

Please note that ODSS results shown here may differ from those previously published or presented. This may occur due to changes in case definitions, methodological approaches, and the ongoing nature of the surveillance cohort.