Contents
Definition Oligoarticular (pauciarticular) JIA
Pediatric arthritis is divided into subgroups which outside the oligoarticular type (discussed here) consist of polyartricular-, entesitt-related- og systemic type. Arthritis is defined as swelling in the joints or reduced joint mobility combined with tenderness / heat, which cannot be explained by other illness or injury. The diseases are also characterized by the risk of complications in other organs, including the eyes. In oligoarticular pediatric arthritis, 1-4 joints are attacked during the first 6 months of the disease, most often knees, ankles and fingers (not hip joints). This type accounts for 50-60% of cases of juvenile arthritis. Most are girls (4 times more common than in boys). The disease usually starts before the age of 6 years.
Subgroups of oligoarticular juvenile arthritis
You can separate two subgroups: 1) Persistent oligoarticular arthritis (English: "persistent oligoarticular") with fewer than 4 affected joints throughout the course of the disease. 2) Polyarticular disease course (English: "extended oligoarticular") with 5 or more affected joints after the first 6 months. Those who get more than 4 affected joints Interior 6 months from the onset of the disease is classified as polyarticular child joints.
Symptoms
Limping. The disease is often detected by limping, refusal to load the leg or that one sees reduced mobility in one or more joints. Knees and / or ankles are most often attacked. In the long term, growth disorders can be seen.
Debut symptoms may be pain and stiffness in affected joints, but young children have a reduced ability to report and locate pain. The child may have general symptoms, a slight fever, malaise and irritability.
Eye Inflammation. Symptoms of uveitis are most often absent. In some cases, reduced vision is only detected by routine ophthalmologist examination, which should always be done.
Examinations
Medical history maps current symptoms (see above). The onset of symptoms, age and number of affected joints are important.
Clinical examined systematically according to routines for children. The number of affected joints with localization is noted. Jaw joints can be attacked, which can lead to reduced gaping ability. In the longer term, the lower jaw may grow smaller and become somewhat retracted (micrognatia). Skin and eyes are also considered. Iris inflammation (uveitis) gives no pain / symptoms in children. However, chronic uveitis results in persistent vision loss in more than 15%, regardless of therapy. Regular check-ups with an ophthalmologist are therefore important.
Blood tests. Inflammation tests such as CRP and SR are often somewhat elevated. ANA (antinuclear antibody is detected in most people, but subgroups of ANA (ENA) are usually absent. Ferritin, cell counts, Borrelia antibody, AST, ANA, RF, anti-CCP, blood culture in high fever or other suspected sepsis, and urine Sticks can be taken if the diagnosis is uncertain.
Joint fluid. In some cases, microscopy, culture and other examination of synovial fluid may be necessary to rule out infection.
Tissue sample (biopsy). If a tissue sample is taken from the joint membrane, it is expected to find tissue with many inflammatory cells. These are not specific for juvenile arthritis and are also found in arthritis in adults (rheumatoid arthritis) (reference: Maggie L, 2019).
Imaging. Ordinary X-rays show the skeleton well, but early arthritis changes are not detected. X-ray examination of joints can still be important with regard to early joint damage (especially in infectious arthritis) and growth disorders in the course. Arthritis often causes overgrowth at first, later the epiphyses close early, so that bone growth stops prematurely. Ultrasound examination is a fast, non-stressful and uncomplicated method that is widely used to detect increased fluid volume and to guide injections. The examination is not painful and is well suited for children. MRI scans are accurate for detecting arthritis that appears earlier than with conventional X-rays (Kirkhus E, 2011). If jaw manifestation is suspected, ultrasound and MRI will detect if there is arthritis. MRI can also be an important method for detecting bone marrow edema in similar diseases as osteomyelitis or articular tumors.
Eye disease, ophthalmologist examination / screening at JIA
Iris inflammation (Unveited) are the most common complication from the eyes by childhood arthritis, especially oligoarticular form. Uveitis in children is caused by juvenile arthritis (JIA) in more than half of the cases and chronic anterior, non-granulomatous uveitis is most common. Girls 4 times more often than boys.
Symptoms: Slight symptoms in children; vision loss without being noticed. Occurs before joint inflammation (arthritis) at 6-7%. The interval between inflamed joints and uveitis is 2 years in 50%. No connection between disease activity in the joint disease and the eye disease.
Diagnosis. Regular eye examination, even without symptoms. TO REACH (antinuclear antibody in blood samples) is present in 75%.
Treatment. Ophthalmologist. Eye drops and other disease-reducing drugs
Follow-up. Recommended regular eye check-ups should be observed. Every 3 months for those most at risk. Chronic idiopathic iridocyclitis in children (almost only girls) also occurs without the presence of arthritis (juvenile chronic iridocyclitis). ANA is present in 30%.
Recommendations; Norwegian Rheumatological Association
Literature; Rodriguex-GArzia A, 2015; Abu Samara K, 2016; The eye of rheumatic diseases is generally described here (Vaskulitt.no)
More information via the National Center for Children and Youth with Rheumatic Disease (NAKBUR)
Similar diseases / differential diagnoses
Joint pain in children can have many causes and is discussed in a separate chapter
Swollen fingers (dactylitis) can be reminiscent of arthritis and seen by Psoriatic arthritis, among older children from 9 years of age at Entesitis related SpA, less frequently by other spondyloarthritis.
High inflammation tests and low blood percentage (anemia) such as SR more than 40 and Hgb less than 11g / dl: Consider Polyarticular disease course available. Borrelia arthritis excluded, especially if only one knee is attacked.
Others: Plant-thorn synovite, septic arthritis (infection), osteomyelitis (infection, often more pain and dramatic onset).
Cancer: Rarely 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: Examination: Blood tests (thrombocytopenia), X-ray, blood smear, bone marrow examination.
Hip manifestation at onset: transient (transient) serous arthritis? Legg-Calve-Perthes, Osteoid osteomyelitis, Neoplasia or infection. Entesitis related SpA.
Treatment
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
Follow-up
- 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
Prognosis
- 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)
Ophthalmic screening: 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
Literature
Children with rheumatic disease, BINDEVEVSSYKDOMMER.no
