Contact Dermatitis

What is contact dermatitis?

The words ‘dermatitis’ and ‘eczema’ are interchangeable and mean the same thing. Contact dermatitis, therefore, is the same thing as contact eczema. For simplicity we will stick to the word ‘dermatitis’ in this leaflet.
Dermatitis means an inflammation of the skin. The term ‘contact dermatitis’ is used when this inflammation is caused by contact with something in the environment.

What causes contact dermatitis? 

Two main groups of things in the environment cause contact dermatitis: irritants and allergens.

Irritants are substances like detergents and solvents that strip the skin of its natural oils, and cause dermatitis to develop if contacted frequently and without skin protection. When this happens, the skin changes are known as an irritant contact dermatitis. The most important factor in causing this type of contact dermatitis is the amount of irritants to which you are exposed. It is particularly common in people who do a lot of wet work, for example nurses, hairdressers, those who work in bars, and those in the catering trade.

Allergens are things to which your immune system can develop a specific reaction after you have come into contact with them. Good examples include substances such as nickel, rubber, and perfumes or preservatives used in some creams and cosmetics. This type of dermatitis is called an allergic contact dermatitis. It is not known why some people who are exposed to these allergens develop it while others do not.

Sometimes substances such as proteins in fruit and vegetables can cause an immediate allergic reaction leading to itchy skin swellings known as contact urticaria (hives), which in turn can aggravate your dermatitis.
Contact dermatitis is not catching or contagious. It is not caused by an infection.

Is contact dermatitis hereditary?

What are the symptoms of contact dermatitis?

Itching of the skin is the commonest symptom, and this can be intense. Sometimes the skin becomes sore, and painful cracks can develop over the backs of the fingers when dermatitis affects the hands.

What does contact dermatitis look like?

The commonest areas on which contact dermatitis occurs are the hands, arms, face and legs. During a flare, contact dermatitis inflames the skin surface making it look red and scaly. Sometimes, tiny water blisters develop and these leak fluid when scratched. When the contact dermatitis is less active, the skin looks thick and dry, and painful little cracks can form over joints.

How will it be diagnosed? 

Irritant contact dermatitis is diagnosed simply by knowing which irritant substances your skin is exposed to, and how often this occurs.
Allergic contact dermatitis is diagnosed by a procedure available in specialist dermatology departments known as patch testing. This involves putting sticky patches containing different substances on your back. The patches are taken off 2 days later, and the doctor or patch test nurse will then look at your back to see which ones have reacted, and will look again after a further 48 hours.

Can contact dermatitis be cured?

Yes - if you can greatly reduce your contact with irritants, then your irritant contact dermatitis will improve or clear.
If patch testing shows that you are allergic to a specific allergen, then avoiding that allergen will usually lead t o a big improvement or even complete clearance of your allergic contact dermatitis.

How can contact dermatitis be treated?

The main way of treating contact dermatitis is to identify its cause (irritant or allergen) and then to remove it or reduce contact with it. Complete avoidance may be easy for some types of allergic contact dermatitis, due for example to a substance such as rubber. But complete avoidance is impossible for some people whose irritant contact dermatitis is due to prolonged contact with water and soap, so measures to protect the skin, such as wearing gloves and using barrier creams, may help. Some people may have to change their job if they cannot otherwise avoid coming into contact with irritants.

It may take several months for contact dermatitis to settle, so topical steroid creams and moisturisers (emollients) are used to help the skin heal and to reduce the itching and redness. Topical steroid creams come in different strengths and it is important that you use the right strength for the right length of time – your doctor will advise you on this. It is also very important to protect your skin and to keep it supple by using a suitable moisturiser several times a day. Thick moisturisers are best for the hands, and it is important that you find one that you like to use.

People with very severe contact dermatitis may need other treatments such as steroid tablets, or medicines such as ciclosporin, to settle things down; these are normally available only from hospital dermatologists.

What can I do?

If you think you might have contact dermatitis, you should see your doctor who may then refer you to a dermatologist for further assessment and patch tests.

If you have contact dermatitis, you can look after your skin by avoiding the offending substances - though this is easier said than done.

Use your moisturisers several times a day.

Take time to look after your skin and follow your doctor’s advice on using the various creams. If they are not working, go back and see your doctor.

While every effort has been made to ensure that the information given in this leaflet is accurate, not every treatment will be suitable or effective for every person. Your own doctor will be able to advise you in greater detail.