Handbook of Juvenile Idiopathic ArthritisAbout This Hardback Juvenile idiopathic arthritis (JIA) is an arthritis which occurs in children and adolescents. It is a noninfective, autoimmune, inflammatory disease of the joints, commonly occurring in children between the ages of 1 and 6. JIA often presents nonspecific symptoms initially such as reduced physical activity, lethargy and poor appetite. Its first noticeable manifestation may be limping. Children may become quite ill with flu like