Atopic dermatitis.

Atopic dermatitis (AD) is an eczematous, highly pruritic chronic inflammatory skin disease. It usually begins early in life and often occurs in people with a personal or family history of asthma and allergic rhinitis. The prevalence is high, especially in children,and it has been rising in recent decades, in parallel with asthma prevalence. Although AD is often described as an "allergic" dis-ease, allergic causation is difficult to document, and AD is increasingly viewed as a skin disease that predisposes to allergies. This interpretation, based on clinical, epidemiologic, and animal stu-dies, may greatly influence our approach to therapy and prevention of atopic diseases in the coming years.