Polyarticular juvenile arthritis (Polyarticular JIA) includes children with arthritis (arthritis) in at least 5 different joints within the first 6 months of the disease. This form of juvenile arthritis can be divided into those without detectable rheumatoid factors (RF, CCP antibody) («seronegative») and the with rheumatoid factors ("seropositive"). Polyarticular juvenile arthritis thus differs oligoarticular form attacking four or fewer joints, entesite-related arthritis og systemic JIA.
Arthritis (polyarthritis) without rheumatoid factors (seronegative)
Polyarticular JIA without rheumatoid factor (seronegative form). This type includes 30% of juvenile arthritis cases and has a girl: boy incidence of 3: 1. The disease most often debuts at the age of 6-12 years.
Polyarticular JIA with rheumatoid factors (seroposive type). Occurs in less than 10% among those with juvenile arthritis. Girl: boy incidence is a whopping 9: 1.
Fever. Young children with multiple inflamed joints may have a fever, marked tiredness, and decreased appetite with weight loss.
Arthritis. All children have at least 5 inflamed joints within the first 6 months from the onset of the disease. Both large joints (knees, ankles, wrists, elbows and small joints such as fingers, toes, neck and jaw joints. Pain and stiffness are not always joints to see, even if the affected joints are swollen, hot and sore. If knees, ankles or feet (rarely in the hip joint) are attacked, limping the child, especially in the morning or after resting.joint joints are attacked, reduced gaping ability is felt. In the long run, the lower jaw can grow smaller and become somewhat retracted (microgantry).
Eye Inflammation (uveitis) can cause permanent damage with reduced vision and occurs in 10%. Those with a result in the blood test ANA have a risk of eye damage of 40%.
Medical history assess symptoms as described above. Heredity is rare, but in seropositive form (see above) arthritis in adults (Rheumatoid arthritis) in the immediate family disposing.
Clinical examination includes systematic assessment of all joints, including neck and jaws. Also, eyes, skin and internal organs are examined.
Blood tests usually shows signs of inflammation such as elevated C-reactive protein (CRP) and blood lowering reaction (SR). Rheumatoid factors (RF), CCP antibody and ANA (antinuclear factors) detected in some, which may be important for the course of the disease.
Imaging done with ultrasound of joints, supplemented with MRI examinations if necessary.
Optometrist. If an eye manifestation is suspected, the child must be examined by an ophthalmologist. Children with ANA results in the blood are most exposed to eye complications with reduced vision and should be routinely assessed up to every 3-6 months. month, otherwise screening every 12 months is relevant (reference: Rodriguex-GArzia A, 2015). Ophthalmological examination is described in the page on oligoarticular JIA
Similar conditions / differential diagnoses
- Borrelia infection after tick bites
- CRMO (non-bacterial multifocal osteomyelitis)
- Dyes lipogranulomatosis (metabolic storage disease)
- Hypermobility syndrome
- Inflammatory bowel disease (IBD) with arthritis
- Rheumatic fever
- Blau syndrome, autoinflammatory disease
- Scurvy (Vitamin C deficiency)
- Pain syndromes in older children, Fibromyalgia-like
- Systemic connective tissue diseases in children (JSLE, Sjögren's syndrome, Dermatomyositis, Systemic sclerosis, MCTD)
The goal of treatment is to achieve the absence of fever, arthritis, permanent joint damage, damage to eyes and internal organs. The treatment should at the same time relieve pain and contribute to as normal an upbringing as possible. Non-drug treatment including physiotherapy is combined with medication. NSAID (ibuprofen, naproxen) has an effect on symptoms, but must usually be combined with other disease-modifying drugs to reduce and stop the disease activity.
Among the antidepressants (DMARDs) are methotrexate (tablets or injections) is useful for most people with polyarticular juvenile arthritis. Methotrexate reduces disease activity and thus pain, stiffness and the development of joint injuries. The effect comes within 2-3 months and usually lasts as long as you use the drug. Although cortisone preparations are avoided as far as possible, often must Prednisolone (tablets) used over a period of time. If necessary, a Biological medicine added, of which TNF inhibitors are the first choice. The longest experience is with etanercept (Benepali, Enbrel) and adalimumab (Humira, Hyrimoz).
The prognosis is generally difficult to predict. High disease activity in the first two years from onset, frequent episodes of fever, many affected joints and anti-CCP antibody are considered risk factors for severe course in the individual (Prieur AM, 2001). In addition, the treatment response will be crucial.
- Thatayatikom A, 2021
- Martini A, 2019 (new classification)
- Barut K, 2017
- Prakke B, Lancet 2011
- Revma Compendium