Dermatitis describes a type of inflammation of the skin. Dermatitis and eczema mean the same thing. Contact dermatitis describes inflammation that is caused by direct skin contact with something in your environment. It is sometimes called contact eczema.
What causes contact dermatitis?
There are two main types of contact dermatitis:
- Irritant contact dermatitis develops when the skin is in contact with irritating substances like detergents and solvents. These strip the skin surface of it’s natural oils. Dermatitis develops when there is regular or prolonged contact with these irritating substances. The most important factors in causing this type of contact dermatitis are the amount and the concentration of the irritating substance touching the skin. It is very common in people who have their hands in water a lot such as nurses, hairdressers, bartenders, cooks and cleaners. People in these occupations often develop hand dermatitis. Anyone can develop an irritant contact hand dermatitis from handling irritating substances or with frequent hand washing.
- Allergic contact dermatitis occurs when allergy develops to a specific chemical or substance that has been in contact with the skin. Examples of these substances include metals such as nickel, rubber, chemicals in hair dye and perfumes or preservatives in creams and cosmetics. It is not known why some people develop allergy to these substances while others do not.
Less commonly substances in fruits and vegetables can cause an immediate allergic reaction when touched. This leads to itchy skin swellings known as contact urticaria (hives). This can lead to a flare of pre-existing dermatitis (eczema).
Contact dermatitis is not infectious and cannot be caught from or spread to other people.
Is contact dermatitis hereditary?
People with a tendency to asthma, eczema and hay fever develop irritant contact dermatitis more frequently than others without these conditions. The tendency to these conditions runs in families.
What are the symptoms of contact dermatitis?
Itching of the skin is the commonest symptom and can be intense. Sometimes the skin becomes sore and red with development of small blisters or painful cracks (fissures).
What does contact dermatitis look like?
The hands are the commonest area where contact dermatitis develops followed by the arms, neck and face. After contact with the irritant or allergenic substance the skin becomes red, dry and flaky. Occasionally weeping and blistering may develop.
How will it be diagnosed?
- Irritant contact dermatitis is diagnosed by the history of exposure to irritating substances and from the appearance of the rash.
- Allergic contact dermatitis is diagnosed by a test available in specialist dermatology departments known as skin patch testing. This involves placing patches containing known allergens on the back. The patches are taken off after 2 days, and the skin that has been tested is examined for the development of dermatitis. Your dermatologist will then be able to advise you what contact allergen you are allergic to.
Can contact dermatitis be cured?
Avoidance of skin contact with irritants or allergens will prevent development of contact dermatitis. Sometimes this may entail the need for a change in occupation e.g. if a hairdresser is allergic to hair dyes.
How can contact dermatitis be treated?
The main way of managing contact dermatitis is to identify the cause and remove the source of the irritant chemical or allergen from contact with the skin. Complete avoidance is not always easy. Therefore, measures to protect the skin, such as wearing gloves, improving the skin barrier with regular emollient creams and avoiding contact with soaps and detergents (see separate leaflet on Hand Dermatitis), are important. Exposure to irritants or allergens in certain occupations may be the cause and may lead to the need for a change of working practice or job.
It may take several months for contact dermatitis to settle. Steroid creams and moisturisers are used to reduce the inflammation of the skin. Topical steroid creams (Topical Corticosteroids) come in different strengths. It is important that you use the right strength for the right length of time. Your doctor or nurse can advise you on this. It is also very important to protect your skin by using an emollient several times a day. Thick emollients are best for the hands. It is important that you find one you tolerate well and that you are able to use regularly.
People with very severe contact dermatitis may need oral (by mouth) medication such as steroid tablets and oral antibiotics.
CAUTION: This leaflet mentions ‘emollients’ (moisturisers). When paraffin-containing emollient products get in contact with dressings, clothing, bed linen or hair, there is a danger that a naked flame or cigarette smoking could cause these to catch fire. To reduce the fire risk, patients using paraffin-containing skincare or haircare products are advised to avoid naked flames completely, including smoking cigarettes and being near people who are smoking or using naked flames. It is also advisable to wash clothing and bed linen regularly, preferably daily.
What can I do?
- If you think you might have contact dermatitis, you should think about measures to protect your skin, such as wearing gloves and avoiding skin contact with soaps and detergents
- Improve your skin barrier by applying non-perfumed emollient creams (moisturisers) such as seborgo daily moisturising cream several times a day.
- You should avoid the chemicals or substances which are causing your irritant or allergic reaction.
Take time to look after your skin both at home and at work and follow your doctor’s advice on using the various creams and treatments.
(Information from the British Skin Foundation)