Thank you to Faren for presenting a mini-case of a young woman presenting with subacute oligoarticular arthritis found to have severe erosive arthritis of the R wrist, elevated CCP and RF factor, consistent with oligoarticular JIA vs. RA, given unclear timeline of symptom onset.
- The ddx for Oligoarticular arthirits is broad. Major categories include infection, crystalline disease, and Rheumatic disease. Check out this previous post for more details.
- The ddx of oligoarticular JIA includes Lyme disease, psoriatic arthritis, enthesitis-related arthritis (ERA), inflammatory bowel disease (IBD), pigmented villonodular synovitis, and malignancy, all of which may initially involve four or fewer joints.
- One should have a low threshold to treat STIs in high risk patients, especially when unsure if a patient will return to clinic for results. In this study to evaluate treatment compliance among asymptomatic adolescents (ages 14-21) with positive STI results, 27% of patients never filled their prescriptions for STI treatment! Consider single dose regimens for GC, Chlamydia, and trichomonas when concerned.
Think of Juvenile Idiopathic Arthritis as an umbrella term for several different categories of disease.
Oligoarticular JIA is the most common JIA category. It is more common in females than males, and the peak incidence is two to three years of age. The typical presentation is limping without complaint. The large joints (particularly knees and ankles) are most commonly affected, but the hips are virtually never the first involved joint. Systemic manifestations other than uveitis are characteristically absent.
Juvenile Idiopathic Arthritis (JIA) Sub-types:
- Systemic JRA (formerly called Still’s disease) (10-15% of JIA cases): patients have rash and intermittent fever, in addition to arthritis of any number of joints.
- Oligoarticular JRA (~50% cases): involvement of < 5 joints after 6 months of illness. This disease is now also broken down into several distinct subgroups with varying prognosis!
- Polyarticular JRA (30-40% cases): involvement of >4 joints after six months of illness. As with oligoarticular JRA, it is now recognized to contain many distinct subgroups with varying prognosis.
Interestingly, annual optho screening is required for those with oligoarticular JIA given uveitis or iridocyclitis occurs in up to 25% of patients, often initially without symptoms.