DermNet NZ

Facts about the skin from DermNet New Zealand Trust. Topic index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Irritant contact dermatitis

Irritant contact dermatitis occurs when chemicals or physical agents damage the surface of the skin faster than the skin is able to repair the damage. The dermatitis or eczema is often well demarcated with a glazed surface but there may be redness, itching, swelling, blistering and scaling of the damaged area. This may be indistinguishable from other types of dermatitis. The severity of the dermatitis is highly variable and depends on many factors including:

Irritants include such everyday things as water, detergents, solvents, acids, alkalis, adhesives, metalworking fluids and friction. Often several of these act together to injure the skin. Irritants damage the skin by removing oils and moisture from its outer layer, allowing the irritants to penetrate more deeply and cause further damage by triggering inflammation.

Irritant contact dermatitis may affect anyone, given sufficient exposure to irritants, but those with atopic dermatitis are particularly susceptible. 80% of cases of occupational hand dermatitis are due to irritants, most often affecting cleaners, hairdressers and food handlers.

Allergic contact dermatitis may look similar to irritant contact dermatitis, but it is caused by an immune response following skin contact with an allergenic substance. Tiny quantities may be sufficient to cause allergy, whereas a certain minimum exposure is necessary for irritant contact dermatitis. Irritant and allergic contact dermatitis may coexist.

Pompholyx eczema (dyshidrotic eczema) may also be difficult to distinguish. In this condition, there are itchy clusters of blisters along the sides of the fingers and on the palms, often triggered by sweating.

Clinical features of contact irritant dermatitis

The dermatitis is usually confined to the site of contact with the irritant, at least at first. If the dermatitis is prolonged or severe it may spread later to previously unaffected areas but it is less likely to do this than allergic contact dermatitis.

Contact irritant dermatitis can appear differently according to the conditions of exposure.

Irritant dermatitis Irritant dermatitis Irritant dermatitis
Contact irritant dermatitis due to saliva

Some typical examples of irritant contact dermatitis include:

In time, the skin may develop some tolerance to mild irritants.

Irritant dermatitis Irritant dermatitis Irritant dermatitis
Irritant hand dermatitis

More images of irritant contact dermatitis ...

Testing for irritant contact dermatitis

Sometimes it is easy to recognise irritant contact dermatitis and no specific tests are necessary. The rash usually heals once the irritant is removed and, if necessary, special treatment is applied. Whilst there are some tests that can provide an indication of the irritant potential of substances, there are no specific tests that can reliably show what the effect of an irritant will be in each individual case. Irritant dermatitis in any case is usually the result of the cumulative effect of multiple irritants.

Patch tests

Patch tests are used to confirm allergic contact dermatitis and identify the allergen(s). They do not exclude irritant contact dermatitis as the two may coexist.

What is the treatment of contact irritant dermatitis?

It is important to recognise how you are in contact with the responsible substance(s) so that, where possible, you can avoid it (them) or at least reduce exposure. Wear appropriate gloves to protect against irritants in your home and work environment.

Irritant contact dermatitis is usually treated with the following:

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Author: Vanessa Ngan, staff writer

DermNet NZ does not provide an on-line consultation service.
If you have any concerns with your skin or its treatment, see a dermatologist for advice.