The interaction between the skin and its immediate environment is amazingly complex. Our knowledge on this, whilst extensive, is still far from complete. One consequence of this is that, no matter how carefully we develop and operate our skin management system, we can never exclude the possibility that someone will suffer an adverse reaction due to exposure to the working environment.
So, you have one or more employees suffering a skin reaction that appears to be due to workplace exposure. What should you do now?
Time for some serious detective work
Given the complexity of the interaction between the skin and the working environment, a simplistic approach may well not identify the true cause (or more probably, causes) of the skin reaction and the subsequent management may make the problem more serious. A further complication is that we have our skin for 24 hours every day, of which only part will be spent at work. If we also take into account the days not spent at work then we spend considerably less time during our working life at work compared with when not in the workplace. Since it matters not to the skin whether the environment is occupational or non-occupational our investigation will have to consider both. The diagram shows the factors that can be responsible for the skin condition, either alone or, more probably, in combination. Omitting any one of these from our investigation may result in an incorrect conclusion, followed by an inappropriate management strategy that could result in a worsening of the problem.
Of course, in many cases there may appear to be a single obvious cause. As case studies later in this article will show, however, omitting to consider alternative causes can easily result in the wrong conclusions being drawn.
Starting from the outside, consider briefly each of the factors shown in the previous diagram.
Occupational – endogenous
This is where the skin is reacting to conditions that are not due to direct contact between the skin and the external working environment. Examples here would be where the affected person has ingested a chemical that has initiated the condition known as systemic contact dermatitis. Dietary nickel in a nickel allergic person is one such condition. Keep in mind that skin uptake via inhalation and ingestion can result in systemic skin conditions. In addition, there are over 100 internal health conditions that can result in what appears to be a condition almost identical to a contact dermatitis.
Occupational – exogenous
This is where the skin is reacting to external exposure to factors in the immediate working environment. Non-occupational – endogenous
Non-occupational – exogenous
This is where the skin is reacting to skin exposure to chemical hazards that are occurring away from the workplace.
This is where exposure due to one or more chemicals is what is causing, or contributing, to the skin problem. Note that these can be occupational, non-occupational, or a combination of both.
Physical will include the effect on the skin of friction, abrasion and other physical effects. This could be occupational, non-occupational or a combination of the two. An example is skin rash that develops due to the presence of minute fibres of glass fibre when laying roof insulation.
For some people genetic make-up can have an important effect on their susceptibility to develop a skin reaction. The most common of these is a condition known as atopy. Atopic persons tend to have drier than normal skin and as a result a less effective skin barrier function than others. They are thus more susceptible to develop irritant and allergic skin reactions.
The skin can be strongly influenced by psychological factors. For example, it is well established that some who suffer from psoriasis may be able to manage this condition reasonably well most of the time, but react strongly to a stressful situation. There are other diseases that are well established to be the result of a psychological condition. In addition, a stressful situation may result in what has been termed dermatitis artefacta due to scratching as a result of a stressful situation.
“it should be clear that a simplistic response is not the ideal approach”
In addition, we may well be faced with a combination of these.
So, where do we start?
From what has already been stated it should be clear that a simplistic response is not the ideal approach. We need a structured approach that ensures that our investigation is properly conducted. The chart shows one possible sequence of steps. It is important to recognise that it is impossible to cover every aspect, consideration and investigative technique in detail in an article of this length. What it can achieve is to create a foundation that can help the reader to avoid some of the common mistakes that can easily be made and to recognise what information they will need to gather and where they may need to seek professional assistance and advice.
We can divide the investigation and management process into four main sections. These can be described as:
- Workplace based evidence collection
- Possible clinical investigation
- Assessment of nature and causation of skin problem
- Management strategy and implementation
The following is a brief examination of each of these.
Workplace based evidence collection
Given that we are investigating what appears to be an occupationally related skin condition it is obvious that we need to obtain comprehensive information about the working environment, the hazards to which the affected person is being, or could be, exposed as a result of their presence and their activities. Note that the exposure could be to something not directly related to their actual work. In addition, it will be necessary to obtain information on any previous skin relevant health issues. This aspect of the investigation will require time spent in the workplace reviewing first hand exactly what happens with this person. However, we should also conduct a more general investigation. It is not uncommon when one person complains about their skin that the workplace investigation reveals more generalised skin issues that others have not reported.
Given that non-occupational exposures could play a contributory role it will be necessary to obtain as much information on these as possible. This information would include, for example, any hobbies, DIY activities, etc. These are particularly important should the skin problem involve irritant skin damage, as irritant contact dermatitis is almost always the result of repeated exposures to different irritant chemicals, many of which will be found away from the workplace.
It may be that at this stage a firm conclusion can be drawn as to the cause of the skin problem; however, caution should be exercised as what may appear the obvious cause may not be substantiated from a clinical investigation. Where there is any doubt a clinical investigation is always recommended.
Possible clinical investigation
The clinical investigation involves the engagement of a dermatologist. Given the complexities of the specialised techniques, the dermatologist should be one who has specialised in contact dermatitis, i.e. holds regular contact dermatitis clinics. It is essential that the dermatologist is fully briefed about the findings from the workplace based evidence investigation as their approach and the tests they conduct will depend on the information available to them. The sequence that they will usually follow is shown in the chart on page 66.
If this is not done then their decisions, and the subsequent diagnosis, will be based on the information provided by the patient. There is then a risk that significant factors may be missed. The subsequent diagnosis may well be what could be termed ‘clinically accurate but occupationally irrelevant’.
Assessment of nature and causation of skin problem
Once the clinical diagnosis has been received it is advisable that this is considered together with the information obtained in the first stage of the investigation. It is always possible, as the case studies show, that a further examination of the evidence and the working environment may reveal that the true cause is not that diagnosed.
“the nickel spot test indicates whether there is any release of nickel molecules sufficient to cause an allergic reaction”
Management strategy and implementation
Assuming that we accept the diagnosis and that it is occupational exposure that is at least the major cause of the skin problem, then obviously we need to take action to eliminate or reduce this to a level where it will not cause an adverse skin reaction. This will depend to a large extent on the nature of the working environment and of the skin condition. Given the enormous variety of working environments and the complexity of the interaction between the skin and the working environment, it is not possible to provide a detailed proposal other than to state that our aim should be to manage the process so as to eliminate any exposure rather than rely on the personal action of the individual.
We may also need to provide the person with guidance on their nonoccupational management of their skin, in particular in the avoidance of exposure to harmful chemicals and in the use of suitable skin care products.
Case study 1 – Occupational allergic contact dermatitis to nickel
In a company producing very small metal components assembly was largely by hand. Several of the components were nickel plated. As there were no chemicals involved the risk assessment had not indicated any need for protective gloves, particularly since a high level of dexterity was required.
A young female employee who had been working on assembly for about two years had developed a severe hand dermatitis. This cleared when she was on holiday for two weeks, but reappeared within a few days of returning to work. She had been sent to the local dermatology clinic for patch testing and been diagnosed as allergic to nickel.
The conclusion from this was that the employer was dealing with an occupational allergic contact dermatitis to the nickel in the plated components. As a number of other employees performed the same work the employer was concerned that they might also develop the same skin problem. We were asked if we could advise on action needed to prevent this.
When the site visit was made, a test was carried out on all the metal components that these workers, as well as the lady with the existing skin problem, would have handled. The aim was to establish whether there was sufficient release of nickel to cause the skin reaction.
The nickel spot test involves using a special chemical to indicate whether there is any release of nickel molecules sufficient to cause an allergic reaction. As the picture shows, no colour change occurred with the stainless steel (chrome-nickel-steel) pen case, indicating that there was no significant release of nickel. By contrast, a test with a one Pound coin produced a substantial colour change, indicating nickel release.
Using this test during a visit to the workplace we were able to show that there was no release of nickel in any of the components that the affected person would have been working with. The diagnosis of sensitisation to nickel was accurate, but in this case irrelevant.
Further investigation revealed that her skin problem was an irritant contact dermatitis to hair styling chemicals as a result of a secondary occupation as a hair stylist. Being an irritant problem, it had not shown up in the patch test.
Of course, her dermatitis had cleared when she was on holiday as during that time she had no contact with the hair styling chemicals.
Case study 2 – Occupational allergic contact dermatitis to epoxy resin
In an aerospace plant a worker had developed what she was claiming was an allergic contact dermatitis due to her contact with epoxy preimpregnated carbon fibre mat. She had been diagnosed by her doctor as being allergic to the mat. The diagnosis was made on the basis that, when a piece of the mat was placed on her skin under adhesive tape for 48 hours, she showed a skin reaction.
Examining the safety data sheet the employer found that the mat contained a high level of tetraglycidyl methylenedianiline (TGMDA), a potent skin sensitiser. As a result they had more or less accepted their responsibility for having caused the skin problem. As a considerable number of other workers performed the same task we were asked to investigate and advise on action that they should take to prevent further skin issues.
The findings from the initial investigation can be summarised as:
- About 50 persons had handled this material on a daily basis, many for around five years. This was the first case of an allergic reaction.
- The mat was cut, using a computer operated cutting machine. Layers were then placed in a metal former until the required thickness was achieved.
- The former with the laminations was placed in a plastic bag and air removed. The bag was then sealed.
- The bag was placed in a large autoclave and baked to cure the resin.
- The carbon fibre mat was abrasive, so the workers wore gloves knitted from a cut resistant material. Such gloves protected against the abrasion, but offered no chemical protection. The material was absorbent, retaining sweat, the gloves becoming damp by the end of the working shift.
Given that the mat was abrasive there was concern about the validity of the clinical diagnosis, as the reaction could easily have been due to irritation under occlusion or due to sweat leaching chemicals out of the material. The patch test had not included the TGMDA as a separate chemical so there was no proper medical confirmation that this was the sensitiser responsible for the skin problem.
The fact that despite the long term use no other worker had ever developed an allergic reaction to the mat suggested to us that the true cause might lie elsewhere.
We argued that were the TGMDA to pass through these gloves to enter the skin, then we would find this chemical also in the used gloves. Normally the workers used a fresh pair of gloves each day. We arranged that a pair would be worn for four days so as to maximise the potential for detection of TGMDA. These were taken to an accredited analytical laboratory to see if TGMDA could be detected in the glove material.
The amount of TGMDA found was minimal and well below the level needed to elicit a reaction in a previously sensitised person, let alone cause sensitisation in the first place.
In other words, even though the gloves had been worn for four times the normal length of time, the TGMDA was insufficiently bioavailable to be responsible for the skin condition. Further investigation revealed a non-occupational cause for the skin problem.
Interestingly, in another location at the site the same mat was softened with a solvent in order to be able to shape it. In this case the solvent was extracting the TGMDA, so appropriate precautions had already been taken. Same material, different hazards!
Should a skin condition develop in a person that might appear to have its roots in the workplace, it is essential that it is correctly investigated. This article cannot be a detailed step-bystep instruction as the action will depend to a considerable extent on the nature of the activities and hazards within the working environment. What it attempts, however, is to describe an outline structure of how the investigation and management should be planned and executed. If correctly done this can frequently enable the affected person to remain at their work. It is not unusual that it also reveals other situations within the workplace that could be potential risks to the skin and thus contributes to a safer working environment.