It is generally agreed that skin disease is the commonest occupationally-caused disease. According to the United Kingdom Health and Safety Executive it accounted for 59% of all reported occupational disease in 1978-79. This reflects the Irish experience in proportional terms, although the total Irish figures are deceptively low. Although the skin is a remarkable and complex organ, the stresses applied to it in some workplaces are extreme and it is unable to perform it’s usual valuable functions. These include the provision of a barrier to harmful bacteria and retention of liquid in the body tissues.
The skin has a number of layers, the uppermost consisting of a thin layer of acid fat soluble secretions from the sebaceous glands. Solvents or prolonged immersion in water will remove this layer. The lower layers are subject to damage from acids, abrasions, cuts, and solvents.
The effects vary, but dermatitis is by far the most frequent manifestation, representing 80% to 90% of the problem. It may arise from a number of causes including physical sources such as heat or cold or excessive exposure to water but most of it is caused by contact with a chemical agent of one or more kinds. Some of these will cause dermatitis in every person exposed to sufficient concentrations, while others are active only as an allergic reaction in sensitive individuals. The symptoms are similar whether the agent is irritant or allergic. They can consist of redness, rash, dry scaling, wet weeping, sores or crust formation.
The agents are very numerous; they include cement, rubber, paint, some woods, tars, dyes, detergents, bricks, oil, leather. The following also cause dermatitis;
Acetic anhydride, Acetonitrile
Allyl alcohol, Anthraquinone
Antinomy, Barium Compounds
Benzene Hexachloride (Lindane), Calcium cyanamide
Chloride of Lime, Chlorinated biphenyls
Chlorinated naphthalenes, Chloronitroanilines
Dinitro-phenols, Epoxy resins
Ethyl acetate, Hexachlorobenzene
Hexamethylene tetramine, Hydroquinone
Phenols, Picric acid
Piperazine, Polychlorinated Biphenyls
Tin compounds, Toluene di-isocyanate
Vinyl acetate, Xylenols
Dermatitis is caused by exposure and appears at the point of contact. The agent may be air-borne, in which case any exposed skin will show symptoms. Skin covered by clothing will be untouched, often resulting in a sharp border line between affected areas and clear skin. If direct contact is involved, the hands are obviously most at risk, but the forehead or other parts of the head may be also affected through contamination from the hands. Occasionally, the wearing of gloves will have protected the hands and only the head will show symptoms. Sometimes the thighs are affected, even through clothing, by rubbing with the hands during work.
Allergic dermatitis requires a period of sensitization to the active agent. This may occur over a variable period of time during which there will be no symptoms. Thereafter, symptoms will appear with each contact with the agent.
Dermatitis is a prescribed occupational disease.