What is dermatitis?

Dermatitis (also called eczema) is a skin inflammation that affects about 20% of people at some time. It causes red, itchy, crusted skin that can become swollen or blistered. Avoiding skin irritants and using emollients, moisturisers and steroid creams or ointments are the common treatments.

Common types of dermatitis

There is no one precise cause for dermatitis. A number of children are born with a tendency to develop a chronic form of dermatitis known as atopic dermatitis (eczema).

People with allergies can react to particular substances from time to time while those with no allergies can be sensitive to irritants - these are both forms of 'contact' dermatitis.

Atopic dermatitis (eczema)
Atopic dermatitis tends to affect the face and skin creases of about 15% of infants and young children. The affected areas (eg, behind the knee, inside the elbow) tend to be very dry and itchy. Scratching is a problem - it can lead to further itchiness, broken skin and skin infections.

Atopic dermatitis is often made worse by hot conditions (and hot baths), soaps and perfumes, woollen clothing, dust or pets. The cause is unknown and there is no permanent cure, but it can be controlled with appropriate advice and treatment. It generally improves with time - most children grow out of it but it can recur, particularly if the skin is exposed to irritants later in life.

Irritant contact dermatitis
This form of contact dermatitis can follow repeated contact with detergents, skin cleansers, acids or alkalis, solvents and other products. Such contact eventually dries the skin and breaks down its protective layers. Irritant dermatitis usually affects the hands.

People in some occupations are more prone to this: nursing and hairdressing (soaps, hot water, shampoos), building and cleaning (solvents) and motor mechanics, for instance. People in such jobs who have had atopic dermatitis should be aware of the risk of flare ups.

Allergic contact dermatitis
This form of contact dermatitis is much less common. It affects people who become oversensitised (allergic) to contact - even very occasionally - with certain everyday substances (unlike irritant dermatitis where regular contact with a range of irritants is the problem).

When you touch a substance you are allergic to, your body's immune system reacts to form a rash at the point of contact (usually the hands), but it may spread, making it difficult to know where it started and what caused it. Only substances you have an allergy to will cause this. Allergies to nickel in jewellery, latex in rubber gloves and clothing elastic, and medical strapping and plasters are quite common.

Possible causes of dermatitis

Looking after your skin

The cause of a rash or scaly patch may not be obvious, so letting your doctor make a proper diagnosis is the first step. You may need to try a cream or medication, have a skin test for allergies or have skin or nail scrapings taken to test for other (secondary) infections.

By carefully avoiding irritants and substances causing allergy, looking after your overall health, taking medications as advised by your doctor and products to keep your skin moist (moisturisers), soft and supple (emollients), you can help improve and protect your skin.

Treatment for dermatitis

Ways to treat dermatitis include:

• Irritants – protect your skin from detergents, chemicals, dust and water
• Bathing – shower rather than take baths, in lukewarm not hot water, use a soap-free cleanser and pat yourself dry rather than rub.
• Moisturisers/emollients – apply liberally and frequently (at least daily).
• Topical corticosteroids – apply to red, itchy patches only. Different strengths may have to be used for different areas. A course is usually two weeks or less.
• Pimecrolimus cream – a non-steroid cream used in specific situations where corticosteroids are not working or are inappropriate.
• Antibiotics – may be needed if infection is also present.
• Antihistamine tablets – may help reduce itching.

Corticosteroid creams

Hydrocortisone is a weak corticosteroid; there are many stronger ones that require much more care. You may be given more than one cream; if so, make sure you understand how to use each one, and:

• use according to a doctor or pharmacist’s advice
• apply only where recommended (and not to broken skin)
• use sparingly – overuse can cause the skin to thin
• use carefully in children or if applied to the face.

TIP: Ask for specific instructions on how to use your topical steroid(s): which one, where, when, how often, and for how long?

Living with dermatitis

Dermatitis is often a long term problem. If your skin tends to be dry, try to avoid excessive bathing and soaps (they are alkaline and the perfumes in them can irritate your skin). Soap substitutes (eg, aqueous cream) can be used instead, and emollients or moisturisers are an important core treatment as they help maintain the skin’s protective barrier function (keeping moisture in and irritants out). They also prevent dry skin and the inflammation that can lead to a flare up of the rash.

TIP: Dry skin is itchy skin. Apply emollients liberally and frequently, ideally after bathing/showering within a few minutes of patting skin dry. Your doctor can prescribe emollients on prescription to cost you less.

When your skin is clear, use emollients to keep skin healthy. If the itchy rash returns, continue the emollient and use the corticosteroid or non-steroid cream or ointment advised by your doctor. If the rash does not improve within two weeks, seek help from your doctor. It is also important to see your doctor if your rash looks infected (weepy, crusted, pustules, no improvement with treatment, or you feel unwell). Adding oatmeal or tar-based pine oil products to your bathwater may relieve itchy skin, as may antihistamine tablets (these may be useful for itching at night).

For allergic dermatitis, finding the substance causing the allergy and avoiding it is the only real cure. Your doctor can arrange for you to have specific allergy tests if the substance causing it is not obvious.

If your dermatitis is caused by household or workplace irritants, you may not be able to avoid them. Using barrier creams or gloves may help protect your skin.

Further information

Talk to your doctor or dermatologist for more information.

Original material provided by everybody, and kindly reviewed by Dr Deborah Greig. Updated November 2011.