SKIN DISORDERS

CLASSIFICATION OF SKIN CONDITIONS

Dermatoses can usefully be divided into two categories:

• non-occupational: not primarily caused by skin contact at work, though some (such as atopic eczema) may be aggravated by it.
• occupational: primarily caused by skin contact at work, though some (such as allergic contact dermatitis from chromate in cement) may continue even after this contact ceases.

The distinction between occupational and non-occupational dermatoses is often difficult to make, largely because the majority of occupational dermatoses and a sizeable proportion of non-occupational dermatoses have a similar clinical appearance. This clinical and histopathological entity is termed eczema or dermatitis; the two words are used synonymously by most dermatologists in this country. However, proper advice on fitness for work cannot be given until the distinction between occupational and non-occupational pattern of disease has been drawn as accurately as possible.

Occupational dermatoses may be broadly divided into two groups:

1. primary irritant contact dermatitis
2. allergic contact dermatitis

The vast majority of dermatoses are not infectious or contagious.

CLINICAL ASPECTS AFFECTING WORK CAPACITY

EFFECT OF THE COMMON OCCUPATIONAL DERMATOSES ON FITNESS FOR WORK

An accurate assessment and determination of the causal factors of the dermatosis is essential. Once guided by a precise diagnosis, changes in working methods and other preventive measures (such as substitution, enclosure, mechanical handling, ventilation, rotation and personal protective equipment) can be helpful. The Control of Substances Hazardous to Health (COSHH) Regulations now provide the legislative mandate for such an assessment, and require that every employee should have adequate information, instruction and training on the substances they handle at work. For those at special risk, regular health surveillance may be required to identify any indication of disease at an early stage.

In most cases of occupational dermatoses, continuation in the same employment is a realistic goal, sometimes with minor adjustments to work practices. This is particularly important in the many occupational dermatoses where prognosis is known to be little altered by change of job. Carefully considered preventive skin care programmes make both the primary and the secondary prevention of occupational dermatoses more effective.

Occasionally, a change of occupation may be in the best interests of the individual. It must be stressed that this should always be preceded by accurate diagnosis. There are certain groups in which a change of job is likely to be indicated. Those who have most of their working life ahead, such as first-year apprentices, may be well advised to give up a job that is already causing them persistent contact dermatitis.

When a decision has been made to advise a change of occupation, it is essential that the alternative occupation should genuinely be more suitable. Clearly, the major requirement is avoidance of the original contact factor(s). This may need expert guidance, particularly when the contact factor is widely used, e.g. allergens such as formaldehyde or irritants such as detergents.

EFFECT OF THE COMMON NON-OCCUPATIONAL DERMATOSES ON FITNESS FOR WORK

Atopic eczema is considered to render the potential employee more susceptible to contact irritants, but only if the condition was severe in childhood and particularly if it involved the hands. Indeed, there is some evidence that it is harder for the atopic to become sensitized to contact allergens than the non-atopic. However, atopics are more susceptible to contact urticaria from Natural Rubber Latex (NRL), and, in this situation, advice will be required not only about the prevention of urticaria but also about asthma and anaphylaxis.

There are few jobs for which a history of severe childhood atopic eczema with hand involvement can be regarded as an absolute contra-indication, but three notable exceptions are hairdressing (shampoo), catering (wet work and detergent), and production engineering (soluble oil). Other occupations that entail significant exposure to contact skin irritants are domestic cleaning, nursing, construction work, motor vehicle maintenance, horticulture, and agriculture.

Involvement of the hands in atopic eczema can pose an entirely separate problem in certain occupations. Lesions of eczema are may be colonized by Staphylococcus Aureus, and sometimes by Streptococcus pyogenes. Any organism which colonizes or contaminates the skin surface is dispersed into the environment on naturally shed skin scales. This has implications in healthcare (patient infection), catering (food poisoning), and the pharmaceutical industry (product contamination). The risk to hospital patients is increased in the immunologically suppressed, though it is not confined to such patients. Hospitals with methicillin-resistant S. aureus (MRSA) strains need to be particularly vigilant as to staphylococcal carriage in staff. The hazard posed by active eczema in these particular occupations is real and requires individual assessment of risk. One further consideration may influence the advice given to atopic subjects. Many essentially endogenous dermatoses are then stated to be aggravated by work exposure, especially if there is known to be a high risk substance, such as chromate, epoxy resin, or a powerful irritant, in the occupational environment.

Psoriasis: Mild psoriasis that does not affect the hands can probably be safely ignored from the point of view of fitness for work, although individual assessments may be necessary according to job requirements. Aggravation of psoriasis by physical or chemical trauma (Kobner phenomenon) can occur occupationally. Occupational factors may elicit it on the hands for the first time in psoriasis-prone individuals though patients with psoriasis vary widely in their liability to hand involvement. If the hands are affected, work involving heavy manual labour, such as scaffolding, or contact with irritants (e.g. in production engineering) may aggravate psoriasis. Colonization of psoriatic lesions with potentially pathogenic bacteria is less of a problem than in atopic eczema and occurs chiefly in people with severe psoriasis who have been hospital in-patients. People with psoriasis which is well-controlled do not generally present a risk to others from bacterial carriage. Psoriasis becomes a potential hazard in those working in hospitals, catering or the pharmaceutical industry if lesions involve the hands, forearms, scalp (common) and face (rare). Nevertheless, the lesser degree of staphylococcal colonization in psoriasis compared to atopic eczema, as well as the wider spectrum of suppressive treatments that now exist for psoriasis, allow greater scope for employment of psoriatics even in such high-risk occupations.

CLINICAL ASSESSMENT

HISTORY

How long (duration) have you had the rash?

Enquire about the rash - Colour Papular/vesicular/pustular/macular/scaly

Distribution- Where did it start?

Itchy?

Speed of onset?

Any known exacerbating factor?

Is there a history of a similar rash in the past?

Any known medical problems? (Hypertension, diabetes, connective tissue disease)

Use of prescribed or OTC medication?

What is your occupation?

Length of time in the job?

Any history of

contact with chemicals (length and duration of exposure)

contact with other substances (dusts, plants, perfumes, etc)

history of allergy, asthma, eczema, hayfever

Working environment (catering, cleaning)

Whether the condition improves away from work?

Anyone else at work with similar rashes?

swelling of face and/or hands

redness of face and/or hands

sneezing, runny eyes

cough, shortness of breath

latex allergy/confirmed(?)

Home environment? (hobbies, DIY, pets)

Anyone else in the family with similar rashes?

EXAMINATION

4 aspects of the lesion(s) need to be recorded: - Morphology - Shape - Distribution - Colour

Morphology

Macule: Flat, non-palpable lesion distinguished from adjacent normal skin by a change in colour.

Papule: Small solid raised lesion <5 mm.

Nodule: Larger raised lesion > 5 mm.

Plaque: Flat topped lesion with a diameter greater than its height

Wheal: Transient swelling of any size, often associated with surrounding localised erythema

Vesicle: A blister < 5 mm.

Bulla: A blister > 5 mm.

Pustule: Visible accumulation of pus

Erosion: An area of skin from which epidermis alone has been lost

Shape

DISTIBUTION

Majority of skin diseases have a characteristic distribution or a predilection for certain sites. Other dermatoses vary in extent of involvement according to their severity.

The distribution of lesions can also be described according to regional involvement, the recognition of which can help pinpoint a diagnosis.

Centrifacial - mostly involving the forehead, nose and chin, e.g. rosacea

Periorbital - distributed around the eyes

Light exposed - Involving skin routinely exposed to sunlight

Perioral - distributed around mouth e.g. perioral dermatitis

COLOUR

Cutaneous lesions can be flesh coloured, demonstrate a change in pigmentation or be characterised by redness. Erythema is redness due to microvascular dilation which can be blanched by pressure. Purpura is a darker cutaneous redness due to erythrocyte extravasation: purpura cannot be blanched by pressure.

ASSESSMENT OF THE JOB

• What does job involve - Describe a typical day or an atypical day
• Does any substance/process precipitate skin problem?
• If so, what?
• How long are you in contact with substance or involved in process?
• Are you required to wash your hands frequently?
• Any symptom free periods?
• If so when?
• What control measures are in place to avoid contact?
• What PPE is provided/worn?

Handwashing - How often?

Use of Detergents, Moisturising/emolients

State of toilets, washing facilities?

Records of risk assessments - Findings and recommendations?

Have the recommendations been acted upon?

ASSESSMENT OF A RASH IN A HEALTH CARE SETTING

COMPARISON OF IRRITANT AND ALLERGIC CONTACT DERMATITIS