Author: Dr Amy Stanway, Department of Dermatology, Waikato Hospital, Hamilton, New Zealand, February 2004.
Atopic dermatitis is a chronic, itchy skin condition that is very common in children but may occur at any age. It is also known as eczema and atopic eczema, and was formerly known as Besnier prurigo. It is the most common form of dermatitis.
Atopic dermatitis usually occurs in people who have an 'atopic tendency'. This means they may develop any or all of three closely linked conditions; atopic dermatitis, asthma and hay fever (allergic rhinitis). Often these conditions run within families with a parent, child or sibling also affected. A family history of asthma, eczema or hay fever is particularly useful in diagnosing atopic dermatitis in infants.
Atopic dermatitis arises because of a complex interaction of genetic and environmental factors. These include defects in skin barrier function making the skin more susceptible to irritation by soap and other contact irritants, the weather, temperature and non-specific triggers: see Causes of atopic dermatitis.
There is quite a variation in the appearance of atopic dermatitis between individuals. From time to time, most people have acute flares with inflamed, red, sometimes blistered and weepy patches. In between flares, the skin may appear normal or suffer from chronic eczema with dry, thickened and itchy areas.
The presence of infection or an additional skin condition, the creams applied, the age of the person, their ethnic origin and other factors can alter the way eczema looks and feels.
There are however some general patterns to where the eczema is found on the body according to the age of the affected person.
Atopic dermatitis affects 15–20% of children but is much less common in adults. It is impossible to predict whether eczema will improve by itself or not in an individual. Sensitive skin persists life-long. A meta-analysis including over 110,000 subjects found that 20% of children with atopic dermatitis still had persistent disease 8 years later. Fewer than 5% had persistent disease 20 years later. Children who developed AD before the age of 2 had a much lower risk of persistent disease than those who developed AD later in childhood or during adolescence.
It is unusual for an infant to be affected with atopic dermatitis before the age of four months but they may suffer from infantile seborrhoeic dermatitis or other rashes prior to this. The onset of atopic dermatitis is usually before two years of age although it can manifest itself in older people for the first time.
Atopic dermatitis is often worst between the ages of two and four but it generally improves after this and may clear altogether by the teens.
Certain occupations such as farming, hairdressing, domestic and industrial cleaning, domestic duties and care-giving expose the skin to various irritants and, sometimes, allergens. This aggravates atopic dermatitis. It is wise to bear this in mind when considering career options — it is usually easier to choose a more suitable occupation from the outset than to change it later.
Treatment of atopic dermatitis may be required for many months and possibly years.
It nearly always requires:
In some cases, management may also include one of more of the following:
Longstanding and severe eczema may be treated with an immunosuppressive agent.
Clinical trials of biologics are promising:
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