Dermatitis is an inflammation of the skin. The term dermatitis is synonymous with eczema. The skin becomes red, itchy, and can be blistered. The skin becomes hard, thickened and cracked. Many people suffer from skin conditions. Most of these are not work related. In some instances these started during childhood. Dermatitis is the main work-related skin disease.
An important clue for diagnosis is the site of the area affected. If it is the hands, contact dermatitis should always be suspected. The next question is whether the ‘contact’ arises from work or outside work.
A work related cause is suggested if:
- The rash is mainly on the hands and exposed skin
- The condition improves away from work and relapses on return
- More than one person is affected in same work area or handling same materials
The following suggest a non occupational cause:
- there is a history of childhood/ endogenous eczema
- there is major involvement of the body trunk or covered area of skin
Occupational dermatitis is a skin disorder caused by coming into contact with certain chemical products in the workplace. It is therefore termed contact dermatitis. Contact dermatitis is the most common work-related disease in Ireland. It can have long term consequences for workers' health and in extreme cases it can hinder their ability to continue working. Research has indicated that 10 years after the condition first occurs, up to 50% of affected workers will still have some skin problems.
It has financial implications in terms of ongoing medical treatment, absence from work, social welfare compensation and possible civil claims. It brings other costs in terms of pain and suffering to affected workers. In many instances it may be totally preventable by simple inexpensive measures.
The outer layer of skin is called the epidermis. New cells are constantly being formed and migrate to the surface over a period of 1-2 months where they die and harden. Here they form a protective layer called the horny layer. This is constantly being worn away by friction. The protective layer is normally worn away but is constantly being regenerated. The problem arises where the rate of damage or wearing to this layer exceeds the rate of repair.
There are 2 forms of contact dermatitis, irritant and allergic.
In contact irritant dermatitis the chemical product that damages the skin is known as the irritant. A highly irritant substance is known as a corrosive. Irritant dermatitis makes up about 80% of contact dermatitis. The other 20% is allergic.
There are several ways that skin damage can be caused.
- Detergents, soaps such as in repeated hand washing or the use of solvents can remove the protective oily layer and so leave the skin exposed to damage.
- Physical damage such as friction, minor cuts for example from fibre glass and grazes can breakdown the protective layer and allow substances access.
- Chemical such as acids or alkalis can burn the layer.
Irritation is analogous to a chemical burn. It acts by eroding or burning the outer protective layers of the skin. Irritant contact dermatitis usually occurs only on the parts of the body in direct contact with the irritant substance for example, hands, forearms, face.
Common irritants are wet work, cutting oils, solvents and degreasing agents which remove the skins outer oily barrier layer and allow easy penetration of hazardous substances, alkalis and acids. Wet cement coming into contact with exposed feet and hands is a particular example of a skin irritant.
In this case, the chemical product causes the worker to become sensitised or to develop an allergic reaction some time after initial contact. The type of allergic mechanism is known as Type IV or delayed hypersensitivity. People do not become allergic to a chemical product immediately at first contact. The sensitisation period (the time between contact and the development of an allergy) can vary from a number of days to months or even years. The risk of becoming allergic depends on several factors:
- The nature of the chemical product. A chemical product with a higher likelihood to cause allergy is known as a skin sensitiser.
- The nature of contact. The higher or more repeated the exposure the more likely it is for the individual to develop sensitisation.
- The vulnerability of the host. Typically people with other allergies are NOT particularly more vulnerable to developing contact allergic dermatitis. Individuals with a previous history of non allergic dermatitis ARE more vulnerable. This may be because the sensitiser may more easily enter the bloodstream in those individuals.
Once the individual becomes sensitised, each time he/she comes into contact with the sensitising product, even in very small amounts, dermatitis will develop. This is different to irritant dermatitis which is dose related. The long term health consequences and ability to remain at work can be significant. In general the majority of an exposed occupational group do NOT become sensitised. It is an idiosyncratic or individual reaction.
Sensitisation is specific to one chemical product or to a group of chemical products that are chemically similar. Once sensitised a person is likely to remain so for life. In allergic dermatitis the rash can occur in areas of the skin not in direct contact with the chemical product the so called “Id” reaction.
Common sensitisers are chromate's (found in cement), nickel (cheap jewellery), epoxy resins, formaldehyde, wood dust, flour, printing plates, chemicals and adhesives.
Both irritant and allergic contact dermatitis can occur together and it is not uncommon for an employee to be exposed to several irritants and sensitisers simultaneously. An irritant contact dermatitis may also develop first, rendering the skin more susceptible to penetration by sensitisers. It is also possible that an original allergic contact dermatitis might be later sustained by an irritant.
- H315: Causes skin irritation
- H314: Causes severe burns and eye damage
The following hazard statement and supplemental statements indicate a contact allergic dermatitis hazard:
- H317: May cause an allergic skin reaction
- EUH 203: Contains chromium(VI). May produce an allergic reaction
- EUH 204: Contains isocyanates. May produce an allergic reaction
- EUH 205: Contains epoxy constituents. May produce an allergic reaction
- EUH 208: Contains ‘name of sensitising substance’. May produce an allergic reaction.
The employer must ensure a safe working environment where exposure to chemical products which can cause dermatitis is prevented or controlled. The employer should have or provide the following:
- An up to date safety statement
- A risk assessment
- Adequate control measures
- Information to employees
- Health surveillance where appropriate
All employers are required to have a written safety statement which must be brought to the attention of all employees. It is a further requirement to implement all health and safety measures identified in the safety statement. The safety statement will include a written risk assessment which will identify if there are chemical products in the workplace that may cause dermatitis. The risk assessment should be able to answer the following questions:
- Are you using one of the chemical product groups listed in Table 1?
- Does the package containing the chemical product have the pictograms GHS07 or GHS05?
- Does the safety data sheet have any of the hazard statements H315, H317 or H314, or any supplementary statements EUH203, 204, 205 or 208?
- What amounts or concentrations are being used? Consider the work process and the collective concentration of all irritants and corrosives used in the process. Remember that the same sensitiser may also be used across multiple products in a given process, so you need to consider the collective concentration.
- Who is likely to be exposed?
- For how long?
- How often?
- Does the exposure exceed the daily occupational exposure level specified in the Chemical Agents Code of Practice?
- Has anybody in the workplace suffered skin problems in the past?
Note: Under the Chemical Agents Code of Practice substances with the Sen notation apply only to respiratory sensitisers. Also chemical products identified with the notation Sk have the capacity to penetrate intact skin and be absorbed directly into the body without necessarily having any effect on the skin.
Both contact irritant and allergic dermatitis can be prevented by prevention or at least minimisation of skin contact with that chemical product. If the Risk Assessment identifies that workers are being exposed to chemical products, the following control measures should be considered to remove, minimise or reduce the risk:
- Removal of the chemical product.
- Substitution with a less hazardous chemical product.
- Closed systems of work which minimise worker contact with the chemical product.
- of excess material using drainage, vacuuming or local exhaust ventilation.
- Washing, drying and applying hand creams. The most effective way of reducing dermatitis is to reduce skin contact with the hazardous chemical product and the easiest way to do this is to wash it off. Good welfare facilities are required including a sufficient number of wash hand basins with hot and cold running water or a mixture of both, hand cleaners, drying facilities and hand creams. The choice of hand cleaners is important as it needs to remove the chemical product but not damage the skin by removing the protective oily layer. They should not contain harsh abrasives or organic solvents. Clean dry towels or disposable paper towels or hot air dryers may be used. The use of hand creams or emollients after washing helps replace the skins natural oily layer.
- Barrier creams. Barrier creams must be used with caution. Very often they are not effective barriers. In general they are not a substitute for appropriately chosen gloves. Even creams which do provide an effective barrier when first applied can wear off quickly when actually working and provide much less effective protection. Unlike when gloves fail, the user will not usually be aware of decreasing protection. Barrier creams may sometimes be used with gloves and sometimes are used to facilitate cleaning of the skin after work.
- Use of personal protective equipment. The objective of personal protective equipment, in this case gloves and clothing is to prevent direct skin contact with the hazardous chemical product. Gloves are useful but care in their selection is vital. No glove provides protection from all chemicals and care must be taken that an appropriate glove is chosen. Glove suppliers can provide advice on the choice of appropriate gloves. If possible latex gloves should be avoided because of the risk of latex allergy but there are occasions when they are still the best option. Sweat is itself an irritant and sweating under gloves can be a problem. Regularly changing gloves and cotton under gloves can help. Apart from gloves and protective overalls, aprons and face masks may be required.
Employees are entitled to information about hazards in the workplace and those contained in the risk assessment. They are also entitled to information on the protective and preventive measures to be taken. Employees who are likely to work with and be exposed to chemical products causing dermatitis need information, instruction and supervision so that they know and understand the following;
- Label and safety data sheet for the chemicals used in the workplace
- Chemical products which are known to cause dermatitis in the workplace
- Risk assessment
- Proper use of control measures
- Need to report any failures in control measures
- Risks to health
- Symptoms of sensitisation
- Importance of reporting symptoms at an early stage
- Role of health surveillance
- Self examining and reporting
Health surveillance is used to detect the early onset or symptoms of dermatitis. The earlier a skin condition is discovered the better the prognosis. It is deemed to be secondary prevention and not as effective as the primary prevention measures outlined above. Health surveillance where used, has to be used in conjunction with these other control measures. Health surveillance can help to show that workplace control measures are working.
Pre-Employment Medical A pre-employment health questionnaire should be completed by all those going to work with chemical products which can cause dermatitis. There may be limitations in employing a person who currently suffers from dermatitis.
A health assessment is usually aimed at identifying an effect of work on health, in this case skin. It may be required before a worker commences work, especially for people with a previous known sensitivity to an irritant or sensitiser used in the workplace. People with pre-existing dermatitis are more likely to develop irritant dermatitis in the workplace. The person carrying out the assessment must be familiar with the chemical products and processes used, standards of cleaning and hygiene and the personal protective equipment used. The initial health assessment can be carried out by a health professional but the decision on whether an individual is suitable for a particular post is normally made by a doctor, preferably one with qualifications in occupational medicine. Dermatitis may be considered a disability and the obligations under Equality Legislation should be considered on the suitability for employment.
Routine Health Surveillance Again the decision whether to carry out health surveillance is based on the risk assessment. When the risk assessment suggests there is the potential for an employee to develop work-related dermatitis because of workplace exposure then usually health surveillance is required.
Because dermatitis is normally evident first to the individual, self-examination and reporting of problems is hugely important. This can only be successful if individuals know what to look out for, what to report and to whom. Employee education and training is vital and should include the principles of prevention, skin care, the early signs of dermatitis and who to report to - usually the occupational health nurse, if present or the company doctor.
Self reporting can be augmented by a skin questionnaire which should be completed again and results compared to pre-employment ones. Ideally, abnormal results should lead to the individual being assessed by a doctor qualified and experienced in occupational medicine or dermatology. If health surveillance indicates that an employee has developed dermatitis, it is important to try to identify the cause. If a suspect cause can be identified and the dermatitis goes way either by avoiding the suspect chemical product or changing work practices, such as using gloves then usually no further action is required. If however the condition persists, the opinion of a specialist occupational physician or dermatologist should be sought. The assessment may include an inspection of the workplace.
If allergic dermatitis is considered patch testing may be performed. The test involves the application of various test substances to the skin under adhesive tape that are then left in place for 48 hours. The skin is then examined on the removal of these patches and again a further 48 hours later for any response. This can help the doctor decide which allergens the employee may be allergic to and identify those that could be aggravating the dermatitis. This is normally carried out by a dermatologist.
Any new case of dermatitis may indicate that the existing control measures are inadequate and the risk assessment should be reviewed and any necessary changes made.