Authors from three pediatric rheumatology centers in Pennsylvania (Children’s Hospital of Philadelphia, Children’s Hospital of Pittsburgh, and Pennsylvania State University Hershey Medical Center) sought to characterize the clinical and laboratory features at presentation of systemic onset juvenile rheumatoid arthritis (systemic onset JRA) to improve the accuracy of diagnosis.
Participating institutions identified patients with a diagnosis of systemic onset JRA seen at their clinic from 1990 to 2005 from their individual patient databases. Patients were included based on the diagnosis of systemic onset JRA made by an attending pediatric rheumatologist. Data from the first encounter with the rheumatologist were collected (regardless of whether systemic onsetJRA criteria were met at that time).
A total of 136 patients were included in the analysis. Similar numbers of girls and boys were affected with about half of the patients presenting between the ages of zero to five years. Most patients were Caucasian (82%) and 14% were African American, mirroring the racial pattern of the state’s population. Fever (98%), arthritis (88%), rash (81%), and lymphadenopathy (31%) were the most common symptoms.
The pattern of fever showed considerable variability: 12% of children had daily morning fevers, 37% had daily evening fevers, 15% had twice-daily fevers, 27% had intermittent fevers, and 5% had continuous fevers. Among patients with arthritis, 47% had polyarticular, 45% oligoarticular, and 8% monoarticular involvement. The most common joints involved were the knee (68%), wrist (68%), and ankle (57%).
Most patients had laboratory evidence of systemic inflammation. Ninety-five percent of patients evaluated had an elevated Westergren ESR (mean 78 mm/h), and 96% (54/56) of patients evaluated had C-reactive protein concentration greater than normal. Median white blood cell count (17.6 x 103 cells/ml) and platelet count (539 x 103 cells/ml) were elevated while the median hemoglobin was low (10.1 g/dl). In 19/26 patients, the aldolase level was elevated. Among the 28 patients who had a bone marrow aspirate, 12 (8% of study patients) had evidence of hemophagocytosis, and had other laboratory features suggestive of macrophage activation syndrome.
Because this was a retrospective study of patients primarily from the 1990s, the older classification terminology of juvenile rheumatoid arthritis (JRA) was used instead of the currently favored International League of Associations for Rheumatology (ILAR) classification of juvenile idiopathic arthritis (JIA; see
Dr. Li has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device....