Skin Diseases
skin diseases
Contact dermatitis is of two kinds
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irritant and
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allergic.
These account for 60% of occupational dermatoses and from 40-70% of all occupationally-acquired illness!
Industries likely to result in dermatitis are:
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food handler/chef
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hairdresser/beautician
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medical/dental/nurse/veterinarian
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agriculture/florist/gardener
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cleaning/laundry
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painting
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mechanical/engineer
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printing/lithography
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construction.
Work-relatedness may be indicated by:
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the association of the condition with
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particular tasks
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exposure to particular substances
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its resolution when away from work.
Contact irritant dermatitis
Contact irritant dermatitis occurs when an irritant is applied to the skin:
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in high enough concentration
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over sufficient time and/or
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with sufficient frequency.
It is made worse by gloves, heat, friction and pre-existing disease. This form of dermatitis usually occurs on the hand or forearm. It is caused by:
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acids and alkalis
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solvents
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detergents/soaps
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abrasives
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enzymes
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oxidants
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oils
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reducing agents
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hygroscopic chemicals
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concentrated salt solutions
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low molecular weight plastics.
Contact allergic dermatitis
Over time, an allergic response develops. The time interval between the first exposure and the development of symptoms depends on:
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the chemical
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the exposure conditions
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skin thickness
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personal factors.
Notes:
- This time period is often measured in years.
- Skin damage increases the risk that an allergy will develop. Sites distant from most obvious contact may be affected (fingers touching the face carry the chemical).
- Some allergic dermatoses require the interaction of sunlight and a chemical - examples include some plants, lichens and sunscreens.
Contact urticaria
Redness and blistering at the site of contact with the chemical within an hour of exposure, and resolving within 24 hours. There are immunological and non-immunological types.
Causes are:
- Non-immunologic: Peru balsam; Ethyl alcohol, caterpillars, jellyfish and moths.
- Immunologic: Seafood, fruits, vegetables, meat/blood, animal secretions, rubber latex.
Control of all forms of dermatitis
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remove from work (if severe)
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prevent contact or at least reduce its frequency and the duration of exposure
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choose gloves carefully – they can make things worse if the chemical gets into them – through a cut or by penetrating the material
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avoid skin trauma
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avoid excessive heat/humidity
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avoid cold and chapping conditions
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use safe work habits
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clean hands with mildest possible cleansers – avoid solvent-soaked rags, dry hands carefully.
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use a different chemical
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use non-rubber gloves
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avoid using allergens.
Treatment: Refer to a specialist. See the Department of Labour A Guide to Occupational Skin Diseases.
Cement Dermatitis
Handling wet cement – or even cement that has not cured properly – may, over time, lead some people (10% according to the UK Health and Safety Executive) to develop a form of dermatitis. This is due to the alkalinity of the cement and contact with chromates that exist naturally in cement.
Cement dermatitis is very hard to treat because, once a person is sensitised, any further exposure to chromates will bring on the symptoms.
This makes it clear that prevention of contact is of paramount importance.
Control:
There are three main strategies.
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Prevent contact by using gloves – if other concrete handling methods won’t prevent contact.
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Wash hands – this implies that running water and adequate hand washing/drying facilities are needed on site.
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Report dermatitis to the employer – if there is not an active programme of health monitoring already
Occupational skin diseases are a widespread problem. Despite numerous protective mechanisms, the skin remains vulnerable to new irritants found in the workplace.
The skin is a good protective cover but it can fail if the load put on it becomes too much. As a result, many workers in different occupations suffer from occupational skin diseases.
What is dermatitis?
Skin diseases caused by substances and processes used in the workplace are commonly known as dermatitis and commonly involve inflammation of the skin.
Most of these skin diseases are due to contact with a harmful agent, which is why they are called contact dermatitis.
Irritant Contact Dermatitis
About 90% of all dermatitis inflammations are caused by contact with one or more of the many irritant agents, in the workplace or elsewhere. Irritant contact dermatitis can occur in anyone, and may occur suddenly after many years of exposure.
The skin becomes red at the site of contact (usually the hands) and blisters, swelling and itching may develop. Over time, the skin becomes thick, rough and cracked. A good example is that of dermatitis in motor mechanics caused by washing car parts with kerosene.
Allergic Contact Dermatitis
Some substances penetrate the dermis and sensitise the skin, so that even very low concentrations of the substance will trigger an allergic reaction in the future.
Sensitisation may occur within days of exposure, but usually takes months to years. That is why workers may suddenly develop an allergy to a substance that they have been working with for years without any problems. Once sensitisation occurs, however, it is life-long and any exposure to the sensitising chemical (or allergen) must be avoided.
Allergic responses vary from person to person, and the rash produced may look just like an irritant contact dermatitis.
Common industrial irritants
* Detergents, solvents, petroleum oils and grease
* Machining (cutting) fluids and various lubricants
* Food substances, plants and fibreglass
Common industrial allergens
* Metallic salts and compounds of nickel, chromate, cobalt and gold
* Uncured epoxy, acrylic and certain resins (hardeners and curing agents)
* Organic dyes, biocides and germicides
If a worker has had severe dermatitis (allergic or irritant) in the past, they need to be made aware of the risks involved in employment in which they will be exposed to high levels of irritant substances, for example hairdressing, catering, nursing or motor repairs.
In addition to these forms of dermatitis, there are other skin disorders in which workplace substances or processes may be involved. These include acne, calluses and scleroderma (a relatively rare disease affecting blood vessels and connective tissue).
The Commonwealth Government's National Industrial Chemical Notification and Assessment (NICNAS) agency found that more than 400 cleaning products used in Australia contain a chemical substance called 2-butoxy-ethanol. This chemical causes irritation of the skin but many of the products did not have adequate warning about the precautions that should be taken for its use.
If you are working with chemicals insist that your employer show you the Material Safety Data Sheet (MSDS) for the products you use. Your employer should take suitable measures to control any health effects and follow safe work procedures when using such products.
What jobs are most at risk?
Occupational skin diseases are a widespread problem. Some occupations where workers can contract severe skin problems are:
* Construction workers, painters - Cement, epoxy resins, paint
* Paint and plastic producers - Isocyanates
* Kitchen, hotel and health care workers - Surfactants, soap, detergents
* Metal machining workers - Mineral oils
* Degreasing workers, cleaners, painters - Solvents
* Drug manufacturers, preparation assistants - Pharmaceuticals
* Hairdressers - Hair treating chemicals
How can skin diseases be prevented?
The following control measures should be taken - the ones at the top of the list are most effective, and should be tried first. As you go down the list, the effectiveness of the control measure decreases.
1. A safer alternative to the product giving the problems should be sought. For example, paints containing epoxies can be replaced by non-epoxy paints, thereby decreasing the risk of sensitisation.
2. The work process should be totally or partially enclosed. For example, total or partial enclosures around machines, parts of machines, or conveyer belts can prevent oil mist and oil splashes contaminating workers' hands and clothing. If it is necessary to see the part being machined, these enclosures can be transparent. Mineral oils are one of the commonest causes of dermatitis.
3. Some work processes can be automated. For example, using a machine to wash paint trays instead of workers scrubbing the trays with solvents. This will eliminate the problems caused by breathing in solvent vapours, as well as skin problems caused by contact with solvents.
4. Work practices could be changed, to eliminate or reduce the chances of skin contact with chemicals. For example, automatic dispensing of organic solvents from drums to containers will reduce the risk of skin irritation from solvent vapours and splashes.
5. Good housekeeping is important. Work areas should be kept as clean as possible. Ensure that surfaces and the outside of bottles and their containers are not splattered with substances.
6. Insist that paper or disposable towels are provided for drying the skin. Toxic materials should not be wiped off with a reusable towel.
7. Isolate work involving chemicals likely to cause skin diseases, so that other workers are not exposed.
8. Protective clothing should be supplied, and laundered, by the employer. Protective clothing should never be taken home.
9. Get advice from manufacturers or suppliers of protective clothing (such as gloves, overalls) on whether the material used has been tested for resistance to the particular chemicals you use.
10. Some gloves used as protection against substances at work may themselves cause skin problems to some users. If a tight fit is not needed, PVC gloves can be used rather than latex gloves.
11. Hand care is important. During long periods of work, remove gloves and give hands an "airing" regularly - at least every hour.
12. Cleansing should be done with soap or other solvent-free hand cleansers, not organic solvents.
13. Hand creams should be provided to replace the oils in the skin removed by frequent washing.
Any substance that may irritate and affect your skin should be identified early and this is helpful in preventing an epidemic of dermatitis in your workplace.
* Read labels on containers, and ask your union delegate, safety committee representative or supervisor to find out more about the skin hazards associated with those chemicals. Follow any precautions that are recommended.
* A Material Safety Data Sheet (MSDS) should be available for each substance used at work. If not, ask for one from your supervisor or the supplier of the product. If you have difficulties in getting one, contact your union or the Workers Health Centre.
* If you notice any changes in your skin, see a doctor immediately. Early diagnosis and advice is essential in preventing occupational dermatitis.
Information on Dermatitis is also available from the ACC website