Types of Occupational Dermatitis

The vast majority of skin diseases that develop in the workplace are dermatitis related. There are other diseases such as psoriasis, tinea, scabies, etc. which can sometimes be confused with dermatitis but a qualified medical professional will be able to distinguish the symptoms of dermatitis from those of the other diseases.

Occupational dermatitis is a skin disease that is caused wholly or partially by the occupation of the individual and manifests as two distinct types; irritant contact dermatitis and allergic contact dermatitis.

Irritant contact dermatitis

The most common form of occupational dermatitis is irritant contact dermatitis. This is caused when a specific irritant in a high enough concentration comes in contact with the skin for a sufficiently long enough time to damage the skin cells.

If a mild irritant is in contact with the skin it will wash away the stratum corneum lipids and prevent the skins’ natural barrier from protecting and regenerating. If the exposure takes place over time the lipids will fail to regenerate and as a consequence dermatitis will often occur in the area of exposure on the skin. This type of dermatitis which occurs over time is sometimes referred to as chronic irritant contact dermatitis.

In the case of strong irritants such as caustic soda typically exposure to the skin will cause immediate damage to the keratinocytes which in turn will produce immediate damage.

There is a susceptibility amongst certain types of people and professions which can be read about in the respective section.

Allergic contact dermatitis

Allergic contact dermatitis occurs when an allergen penetrates the skin and combines with the skin immune cells. The allergen (or sometimes referred to as the sensitiser) then moves to the lymph glands where they react with T-lymphocytes which produce cells which remember the particular allergen.

Once sensitisation to the allergen has occurred, with every subsequent exposure the T-cells (T-lymphocytes) recognise the allergen and multiply releasing substances such as histamine which causes the symptoms of allergic contact dermatitis.

Hypersensitivity to the allergen can happen after the first exposure or over time after repeated exposure. This can depend on the type of allergen and the susceptibility of the immune system of the person exposed. Once a person has become sensitised to the allergen it is likely that the sensitisation will remain with that person for the rest of their life.

It is not uncommon for irritant and allergic contact dermatitis to occur together – often sufferers will get dermatitis on the hands. If an individual is already suffering from irritant dermatitis then the cumulative effect of that condition can contribute towards allergens being able to penetrate the damaged skin to a greater extent thus producing irritant and allergic contact dermatitis in the sufferer.

Overall, contact dermatitis is found to affect the hands in around 75% of cases and in cases of occupational contact dermatitis 90% of all cases affect the hands.

It is a very common condition in the workplace with around 35,000 new cases of occupational dermatitis being recorded in the UK between 2010 and 2012.