JUVENILE CHRONIC ARTHRITIS IN COSTA-RICA - A PILOT REFERRAL STUDY

In order to adequately care for patients with chronic disorders and to properly allocate resources, the epidemiology of the underlying disea se must be known. Proper population based studies involve substantial planning and educational programs, however: To prepare for such a stud y of pediatric rheumatic disorders, we performed a referral-based pilo t study. During an eleven-month period pediatricians all over Costa Ri ca were asked to refer to us all new cases of possible rheumatic disor ders among children less than 16 years of age, using the EULAR criteri a for juvenile chronic arthritis. The children were evaluated at the N ational Children's Hospital. An annual incidence of 5.9 cases of all t ypes of pediatric rheumatic diseases per 100,000 was found. Incidences of 5.4 per 100, 000 children below 16 years of age and 6.1 for childr en below 12 years of age were observed for juvenile chronic arthritis (JCA). 77% of the JCA cases were of pauciarticular onset, and 23% were of polyarticular onset. No cases of systemic JCA were diagnosed, The female to male ratio was 3:2. Antinuclear antibodies were positive in 13% of the JCA cases, and IgM rheumatoid factor was found in 15% of th e children. Chronic iritis was noted in only 2 cases; both were girls and both were ANA positive. The incidence found was low compared to po pulation-based studies, but in the same range as hospital-based invest igations.