Oligoarticular childhood arthritis attacks up to four joints, most often knees
Contents
Definition Oligoarticular (pauciarticular) JIA
During the first 6 months of the disease, 1-4 joints are attacked, most often knees, ankles and fingers (not hip joints).
Occurrence
- Compose 50-60% of childhood arthritis cases
- Girl: boy incidence is 4: 1
- The disease usually starts before the age of 6 years
- This JIA type often has only slightly elevated or normal c-reactive protein (CRP) and Erythrocyte sedimentation rate (ESR) in blood samples
subgroups
- One can distinguish two subgroups:
- Persistent oligoarticular arthritis ("persistent oligoarticular") with less than 4 attacked joints throughout the course of the disease
- Polyarticular disease course ("Extended oligoarticular") with 5 or more affected joints after the first 6 months
- Those who receive more than 4 affected joints within 6 months of onset of disease are classified as polyarticular child joints
Oligoarticular juvenile arthritis. Arthritis of the right knee. Giancane G, Rheumatol Ther (2016). Open
Jaw joint
Jaw joints can be attacked, which can lead to reduced gaping ability. In the long run, the lower jaw may grow smaller and become somewhat retracted. In addition to clinical examination, ultrasound and MRI will show if there is arthritis in the jaw joint.
Eye Disease
Inflammation of the eye (Uveitis) with blurred lens in juvenile arthritis. Asproudis I, Clin Ophthalmol (2010). Open
- Uveitis (iris inflammation) gives no pain / symptoms in children
- Chronic uveitis causes persistent vision loss in more than 15%, regardless of therapy. Risk of blindness
- Screening by ophthalmologist:
- When the blood test ANA is available («ANA positive»): Ophthalmologist every 4 months for the first few years. If the baby's eyes are not affected, the control intervals are extended after 5 years to every 6 months
- When ANA is not available («ANA negative»): Ophthalmologist every 6 months
Incorrect diagnosis? (Similar diseases / differential diagnoses)
- Joint pain in children, please read here (in Danish)
- Swollen fingers (Dactylitis): Consider psoriasis arthritis (see below). If the child is 9 years or older, consider also Entesitis related SpA
- High inflammation tests and anemia (SR more than 40, Hgb less than 11g / dl): Please reconsider Polyarticular disease course may be present
- Borrelia arthritis
- Others: Plant-thorn synovite, septic arthritis (infection), Osteomyelitis (infection, often more pain and dramatic debut), Lyme disease
- Neoplasia / cancer: Rare with Pain in just one or a few joints (More general or varying skeletal pain and affected general condition)
- Acute Lymphatic Leukemia og neuroblastoma may debut with joint pain in the same age group
- Investigation: Blood tests (thrombocytopenia), X-rays, Blood smears, Bone marrow examination
- Hip Infection at Onset: Toxic Synovitis (Transient)? Legg-Calve-Perthes, Osteoid osteomyelitis, Neoplasia or infection. Entesitis related SpA
Treatment of oligoarticular JIA
The aim of the treatment is to achieve absence of arthritis, permanent joint injury, damage to the eyes and internal organs. The treatment should at the same time alleviate pain and contribute to as normal upbringing as possible
- NSAIDs (Ibuprofen, naproxen and others)
- Joint puncture (in narcosis in small children) with tapping and injection of corticosteroid (most often LederSpan, Triamcinolonheksacetonid)
- Methotrexate in some treatment-resistant cases
- Biological supplementary treatment in some treatment-resistant cases
- The treatment is not healing but works for as long as it is used
Medical Prognosis (oligoarticular type)
- All children with this disease must be investigated and followed up
- Most respond well to treatment and some are without symptoms within 6 months
- Recurrences (relapses) at 20%, especially first year, but late-relapses after 5 years is possible
- Over 50% are without disease (remission) in the long run
- Those with polyarticular disease (see above) are most prone to permanent disease (and prolonged treatment / follow-up)
- Signs of poor prognosis: Symmetric joint defect (the corresponding joints on the opposite side of the body), erosions (damage seen on X-rays), persistent arthritis / synovitis, reduced physical function. Ankle and / or inflammation of the wrist, persistent rash in inflammatory parameters (SR, CRP)
