A structured questionnaire was used to assess the epidemiology and clinical features of childhood onset psoriasis (COP; n = 715) and adult onset psoriasis (AOP; n = 1211) in the Netherlands in 2009. In 37.1% of patients the initial signs of the disease appeared before 18 years. COP, as opposed to AOP, occurs predominantly in females (62.9 vs. 45.2%), has a longer delay in diagnosis (3.1 years vs. 1.5 years) and a higher incidence of familial distribution (78 vs. 61%). Development of guttate and erythrodermic COP in adulthood is most often seen in COP. Body mass index in adulthood, disease severity in later life and the type of treatment used ...