Psoriasis is a common chronic disease in childhood of yet unclear etiology. Thirty per cent of psoriatic patients experience onset of their disease before 15 years of age. Psoriasis is exceptionally congenital but may present in infancy as a napkin dermatitis. There are specific pediatric clinical forms, but at the beginning the eruption is usually discrete, and the diagnosis can be difficult. Pustular, erythrodermic and arthropathic forms are rare. Treatment must weigh the advantages and disadvantages of the possible therapies and be kept to the minimum compatible with asymptomatic control.