Download Module 6

Introduction
#outcomes
Learning Outcomes
After successfully completing this module, you will be able to:
1. describe basic skin structure and function.
2. name factors that are known to predispose some workers to occupational skin diseases.
3. describe primary irritant contact dermatitis and allergic contact dermatitis.
4. list some common marginal and absolute irritants encountered in the workplace.
5. list some common chemical agents that cause allergic contact dermatitis in the workplace.
6. list common biological agents responsible for occupational skin infections.
7. describe the significance of chloracne and pigment disorders in the workplace.
8. list and describe the elements of a complete occupational skin disease prevention program.
/outcomes
#reading
Read
Selected pages from:
Levy, B., Wegman, D., Baron, S., & Sokas, R. (Eds.). (2011). Occupational health: Recognizing and
preventing disease and injury (6th ed.). Toronto, ON: Oxford University Press.
/readings
#link
Web Resources
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Canadian Centre for Occupational Health and Safety. OSH answers: Allergic contact
dermatitis.
Canadian Centre for Occupational Health and Safety. OSH answers: Irritant contact
dermatitis.
/link
Skin Disorders in the Workplace
Depending on how the statistics are viewed, the importance of skin disorders in the workplace is
either greatly exaggerated or greatly underestimated. Either way, occupational skin diseases are
common in many workplaces and the number of chemical, physical, and biological agents that can
cause skin disease in the workplace is very large.
#case
Research
Title: Occupational Contact Dermatitis
Author: Sasseville, D.,University of Manchester.
Journal: Allergy Asthma Clinical Immunology, 2008, 4(2): 59-65
Summary: Occupational contact dermatitis accounts for 90% of all cases of work-related cutaneous
disorders. It can be divided into irritant contact dermatitis, which occurs in 80% of cases, and allergic
contact dermatitis. In most cases, both types will present as eczematous lesions on exposed parts of
the body, notably the hands. Accurate diagnosis relies on meticulous history taking, thorough
physical examination, careful reading of Material Safety Data Sheets to distinguish between irritants
and allergens, and comprehensive patch testing to confirm or rule out allergic sensitization.
/case
#link
Web Resources
National Institute of Health
/link
#Readings
Read: Levy and Wegman, Skin disorders, pages 476–488.
/Readings
#Activity
Learning Activity #1/Perspectives
#accordion
1. Why do you think that “it is estimated that the actual incidence of occupational
skin disease is 10 to 50 times higher than the reported incidence”?
It is difficult to say with certainty. It may be that because these diseases are often not disabling and
that many of the treatments are “routine,” neither the worker nor the doctor feels that reporting is
necessary. Also, non-occupational dermatitis often resembles occupational dermatitis.
2. Review the textbook information on skin structure and function. Then, in
nontechnical terms, describe the structure and function of the skin to a
nontechnically-oriented friend.
How did you do with your explanation? “Translating” technical information into terms that a worker
can understand is a critical skill for a health and safety professional.
3. Briefly summarize the pre-existing skin “conditions” that make some workers more
susceptible to skin disorders.
Atopic dermatitis, psoriasis, poorly pigmented skin, excessive sweat gland function, and disorders of
the pilosebaceous units, such as acne, can make workers more susceptible to some occupational skin
disorders.
/accordion
/activity
#case
Research
Title: Occupational dermatitis causing days away from work in US industry, 1993.
Authors: C.A. Burnett, B.D. Lushniask, W. McCarthy and J. Kaufman. NIOSH.
Journal: American Journal of Industrial Medicine, 34(6), 568-573, 1998.
Summary: In 1993 there were an estimated 8,835 cases of occupational dermatitis reported in an
annual survey by the Bureau of Labor Statistics, a rate of 1.12 cases per 10,000 workers. The largest
number of cases were seen in health care industries while the highest rate was in agriculture. The
occupation with the largest number of cases was non-construction laborers. Cleaning and polishing
agents, especially those containing calcium hydroxide and other oxides, caused the largest number of
cases and resulted in a median of nine days away from work.
/case
Occupational Skin Disorders
Occupational physicians and dermatologists have established a system of categorizing skin disorders
that is generally used throughout the world.
In some articles you may see references to substances that are classed as marginal irritants and
absolute irritants.
Marginal irritants are substances that require repeated or prolonged skin contact to produce
inflammation. Examples include many soaps, detergents and organic solvents.
Absolute irritants are substances that injure the skin immediately on first contact and include strong
acids and alkalis.
#activity
Learning Activity #2 Perspectives
Refer to Table 22-4, p. 486 in your textbook and the material in the readings.
1. Think about workplaces you have worked in. Were there opportunities in any of
these workplaces for you to have skin contact with any of the agents listed in the
table?
#reveal
button: Answer
With such a large list of agents that will cause occupational skin disorders, it is very likely that we all
have worked in situations where skin contact with at least one of these agents was possible.
/reveal
#accordion
2. What is primary irritant contact dermatitis?
A non-allergic reaction of the skin caused by exposure to irritating substances.
3. What is allergic contact dermatitis?
An allergic reaction of the skin caused by initial sensitization to an agent and the development of a
hypersensitivity to future contacts with the agent.
4. What symptoms are associated with acute contact dermatitis? What symptoms
are associated with chronic contact dermatitis?
Acute contact dermatitis is characterized by redness, swelling, vesicle and blister formation,
exudation, and crusting and scaling at the site of skin contact. Chronic contact dermatitis is
characterized by skin thickening, loss of external layers of the skin (excoriation), and changes in
pigmentation.
5. What is a ‘marginal irritant”?
Marginal irritants are those that require repeated or prolonged skin contact to produce inflammation.
Examples include many soaps, detergents, and organic solvents.
6. What is an ‘absolute irritant’?
Absolute irritants injure the skin immediately on first contact. Examples include strong acids e.g.
sulphuric acid or strong alkalis e.g. caustic soda.
/accordion
7. Many types of non-occupational dermatitis look exactly like occupational
dermatitis. How does a doctor distinguish between occupational and nonoccupational dermatitis?
#reveal
button: Answer
The most critical factor is for the doctor to take an “accurate, detailed, and discerning history” of the
worker (detailed job description, list of agents the worker is exposed to at work and at home).
/reveal
8. List one example for each of the following:
a. fungus that causes occupational skin infection
#reveal
button: Answer
examples of fungi include ringworm fungi and Candida
/reveal
b. bacterium that causes occupational skin infection
#reveal
button: Answer
examples of common bacteria are streptococci and staphylococci
/reveal
c. virus that causes occupational skin infection
#reveal
button: Answer
examples of viruses include wart-causing viruses and Herpes simplex
/reveal
9. Bigby et al. say that chloracne is not a disabling illness (page 544). If that is the
case, why should a health and safety professional be concerned about cases of
chloracne in the workplace?
#reveal
button: Answer
The lesions themselves are disfiguring. The fact that a worker has chloracne means that it is likely
that the worker is also experiencing absorption of halogenated aromatic hydrocarbons through the
skin. Some of these chemicals are associated with skin, lung, and bladder cancer.
/reveal
10. Pigment disorders are also not disabling illnesses. Why should a health and
safety professional be concerned about cases of pigment disorder in the workplace?
#reveal
button: Answer
The changes in pigmentation are disfiguring. There is some evidence that pigmentation changes
resulting from trauma to the skin can lead to the development of skin cancer.
/reveal
/activity
#case
Research
Title: Allergic contact dermatitis in American aircraft manufacture.
Author: J.P. Hackett.
Journal: American Journal of Contact Dermatitis, 10(3), 157-166, 1999.
Summary: There is a lack of generally available information on the materials used in modern aircraft
manufacture, and the allergic contact dermatitis caused by these materials. To develop more
information, the cases of 44 aircraft manufacturing workers with allergic contact dermatitis were
reviewed. More probably than not, all of these cases were caused by a specific material in the
workplace. Although, many common chemicals appeared in these cases with predictable frequency,
the use of “pre-preg” materials and modern sealants often led to allergic contact dermatitis, that could
not be diagnosed with standard screening test methods.
/case
Prevention of Occupational Skin
Disorders
We know enough about most occupational skin disorders that we can design very effective prevention
programs. Many of these programs have been used successfully for many years. However, some
prevention methods, particularly the use of “barrier creams,” are heavily marketed to health and
safety professionals and are often “oversold.”
#case
Research
Title: Efficacy of a barrier cream and its vehicle as protective measures against occupational irritant
contact dermatitis.
Authors: U. Berndt, W. Wigger-Alberti, B. Gabard and P. Elsner.
Friedrich-Schiller University, Germany.
Journal: Contact Dermatitis, 42(2), 77–80, 2000.
Summary: The advantage of barrier creams over standard skin moisturizers for skin protection is
hotly debated. In this randomized, double-blinded study, the efficacy of a newly introduced barrier
cream and the skin moisturizer used as a vehicle for the “active ingredients” in the barrier cream were
tested. The materials were tested on two groups of nurses suffering mild irritant contact dermatitis.
The results showed no significant differences between the barrier cream and the vehicle. In both
groups of nurses, clinical skin status improved significantly. In this case, the skin moisturizer alone is
capable of positively influencing skin status.
/case
#activity
Learning Activity #3/Perspectives
1. Protective or “barrier” creams are increasingly being marketed to the health and
safety professional. What are the four general types of barrier cream?
#reveal
button: Answer
Vanishing creams, water-repellent creams, solvent-repellent creams, special creams.
/reveal
2. Discuss the advantages and disadvantages of using barrier creams as part of an
occupational skin disease prevention program.
#reveal
button: Answer
Advantages: can be useful when other PPE is not possible, encourages workers to wash, some are
very effective for the job they are designed for.
Disadvantages: may be expensive, may provide a false sense of security, may allow employers and
workers to avoid considering other control methods.
/reveal
#accordion
3. What personal measures can a worker take to help prevent occupational skin
disease?
Personal cleanliness is critical. Personal responsibility for environmental cleanliness at the
workstation, where this is possible. Personal decisions by those workers with predisposing factors to
either avoid the employment or to carefully follow safe work procedures.
4. Name the three principal layers of the skin.
Epidermis, dermis, and subcutaneous tissue.
5. Describe the function of the most superficial layer of the skin.
The epidermis is the primary skin barrier that retains water and interferes with the entrance of
microorganisms and toxic substances.
/accordion
6. List any three factors that are known to predispose workers to developing
occupational skin diseases.
#reveal
button: Answer
Any three of: atopic dermatitis, psoriasis, poorly pigmented skin, excessive sweat gland function, and
disorders affecting the pilosebaceous units.
/reveal
7. List any four measures that are often part of an occupational skin disease
prevention program.
#reveal
button: Answer
Any four of:
 environmental cleanliness,
 personal cleanliness,
 protective clothing,
 protective creams, and
 pre-placement screening
/reveal
/activity