[Atopic dermatitis: definition, epidemiology, natural history, severity and scores].

This paper is aimed at defining atopic dermatitis (AD) in a pragmatic and historical perspective (diagnostic criteria, severity scores, quality of life scales) and to summarise its natural history, complications included. The signification of atopy is still not clearly defined. Immuno-allergologists tend to limit the term to a hereditary predisposition of the immune system. The definition of atopic dermatitis in infants has not been validated. Atopic dermatitis in France has a prevalence of 2 to 5 p. 100 at any age (6 to 9 p. 100 before the age of 15), depending on the strictness of the criteria applied. For infants suffering from AD with a first degree parent exhibiting AD, asthma or rhinitis, the risk of developing asthma is of around 40 p. 100. This data suggests the interest of preventive measures targeting the skin in the hypothesis of an atopic "march". There is no consensus to define the terms used in the description of the maintenance phase of treatment of this chronic and recurring affection. Proposals have been made to define the terms of flares, remission, intolerance and resistance.