Atopic eczema is a pruriginous dermatosis that most often starts before one year, but which may show for the first time after 50 years. The diagnosis is essentially clinical, with signs of banal eczema (especially acute in young infants, more chronic later) but of which the topography develops characteristically as a function of age and in the context of atopy. The development of is chronic, dotted with inflamed eruptions and may be complicated by an alteration of general state with bacterial (very frequent) or viral superinfections. The appearance of asthma is frequent when the dermatosis is extended. It usually disappears before adult age. Differential diagnosis is needed especially when there is an atypical form or association with another pruriginous dermatosis. Questioning must cover the environment, food habits and search for signs that may show the responsibility of an allergen.