Psoriasis vulgaris can occur at any age, and prevalence in childhood ranges between 0.1% and 1.5%, showing a nearly linear increase from birth to the age of 18 years. Early onset is more frequently associated with a positive family history and heralds a graver prognosis. The median age at onset of psoriasis was found to be between 7 and 10 years. Data from the UK suggest a prevalence of 0.55% in the age group 0–9 years and 1.37% in the age group 10–19 years, which is consistent with data from the Netherlands, Germany and the USA. Estimates of the proportion of psoriatic children with a positive family history in any family member range between 4.5% and 88%. Psoriasis may represent 4.1% of all dermatological diseases under the age of 16 in Europe and North America. The reported percentage of children developing guttate psoriasis ranges from 6.4% to 44%. Although guttate psoriasis is mostly self-limiting, resolving within 3–4 months of onset, the long-term prognosis is unknown. About one third of children with guttate psoriasis develop classical plaque-type disease. Nail involvement is reported in between 2% and 39.3% of children. Increasing evidence suggests an association between juvenile psoriasis and other morbidities including hyperlipidaemia, obesity, hypertension, diabetes mellitus and rheumatoid arthritis. Disease patterns of the metabolic syndrome may occur independently of patient age and disease duration. A high proportion of children and adolescents will continue to have psoriatic disease and comorbidity throughout their lives, suggesting the need for careful work-up and specialized care and information.