Childhood psoriasis.

Psoriasis commences by the age of 15 years in one third of patients and is an important childhood disorder. Various human leukocyte antigen associations are important in predisposition to psoriasis, and streptococcal disease is important in its precipitation and exacerbation. The disorder takes many clinical forms, with guttate lesions and anogenital and facial involvement being particularly prominent in the childhood age group. Pustular psoriasis and psoriatic arthropathy are rare in this group of patients. It is important to take the age of the patient into account when making treatment choices.