Atopic dermatitis (AD) is a common skin condition with significant associated social and financial burden. AD affects adults and children with worldwide prevalence rates of 1-20%. International study of epidemiology and geographic variability in prevalence of AD has been conducted in three phases with 1,000,000 subjects in the third phase study. Prevalence continues to vary and has changed in different regions of the world. Nigeria, the United Kingdom and New Zealand had been areas of the highest prevalence; Latin America has emerged as a region of relatively high prevalence in follow up data. The prevalence of AD seems to have reached a plateau around 20% in countries with the highest prevalence, suggesting that AD may not be on a continued rise but that a finite number of individuals may be susceptible to the condition. Risk factors associated with increased prevalence include higher socioeconomic status, higher level of family education, smaller family size and urban environment. Research indicates that food allergy and atopic sensitization to environmental allergens may not be directly causal of the condition and that a non-atopic form of the condition exists. ∼60% of patients will experience remission. The number of patients who will progress through the atopic march to develop asthma and allergic rhinitis depends on the underlying features of their condition.