What is Juvenile Idiopathic Arthritis
Juvenile idiopathic arthritis (JIA) is a medical condition that occurs in children and adolescents, characterized by inflammation of their joints. This is a chronic form of arthritis that appears in people under 16 years of age and is one of the most common types of arthritis in children. The name “idiopathic” is used because the exact cause of JIA is unknown, although genetic and immunological factors are believed to play a role in its development. JIA may last for a limited period of time, such as a few months or years, but in some cases, it is a lifelong disease that requires treatment into adulthood.
Juvenile Idiopathic Arthritis Subtype
1. Oligoarthritis
Oligoarthritis is the most common sub-type. This type attacks four joints or less during the first 6 months. There are two types of oligoarthritis, namely persistent oligoarthritis (arthritis in four joints or less during the entire 6 month course of the disease) extended oligoarthritis (arthritis in five or more joints after the initial 6 months of the disease).
2. Rheumatoid factor (RF) negative polyarthritis
As the name suggests, Rheumatoid factor (RF) positive polyarthritis is arthritis that attacks 5 or more joints during the first 6 months of the disease, with a negative RF test.
3. Rheumatoid factor (RF) positive polyarthritis
Rheumatoid factor (RF) positive polyarthritis is arthritis that affects 5 or more joints during the first 6 months of the disease, with 2 or more positive RF tests at least 3 months apart during the first 6 months of the disease.
4. Systemic arthritis
Systemic arthritis is arthritis in one or more joints with or preceded by fever lasting at least 2 weeks which is recorded as occurring every day for at least 3 days, and is accompanied by one or more of the following symptoms:
- Erythematous rash that comes and goes
- Generalized enlargement of lymph nodes
- Hepatomegaly and/or splenomegaly
- Serositis
5. Psoriatic arthritis
Psoriatic arthritis is arthritis and psoriasis, or inflammation of the joints and is accompanied by at least the following 2 things:
- Dactylitis
- Hollow nails or onycholysis
- First degree psoriasis
6. Enthesitis-related arthritis
Enthesitis-related arthritis is a condition of arthritis and enthesitis, or arthritis or enthesitis with at least 2 of the following:
- Presence or history of sacroiliac joint tenderness and/or lumbosacral inflammatory pain
- The presence of the HLA-B27 antigen
- The onset of arthritis in men over 6 years of age
- Acute anterior uveitis
- History of ankylosing spondylitis, arthritis associated with enthesitis, sacroiliitis with inflammatory bowel disease, Reiter's syndrome, or acute anterior uveitis in a first degree relative
7. Undifferentiated arthritis
Undifferentiated arthritis is arthritis that does not meet the criteria in any category or in 2 or more of the categories above
Causes of JIA
The causes and triggers of chronic arthritis in JIA are still unclear. Abnormal immune responses triggered by interactions between environmental factors in genetically susceptible individuals remain speculative. Some environmental factors such as antibiotic exposure and cesarean section are potential risks. The role of microorganisms such as Parvovirus B19, Epstein-Barr virus, enteric bacteria, Chlamydophila pneumoniae, and streptococcal infections remains uncertain.
Clinical Manifestations of JIA
JIA has the general pattern of inflammatory joint disease (synovitis, joint effusion, soft tissue swelling, osteopenia, bone edema, and erosion) with some additional elements related to developmental age, such as impaired epiphyseal growth, premature physical fusion, and unequal limb length. Each JIA sub-type has different clinical manifestations.
- Oligoarthritis
This type of oligoarthritis usually affects the large joints of the lower extremities in an asymmetric pattern. Because oligoarthritis tends to affect toddlers, the first symptom parents may notice is weak or swollen joints. The knees and ankles are the joints most commonly affected. The joint may feel warm, but not red or very painful. The surrounding muscles may become atrophic as the child becomes increasingly immobile.
- Rheumatoid factor (RF) negative polyarthritis
The onset of RF negative polyarthritis is most variable. The onset can be acute or progressive. Large and small joints are affected in a symmetrical or asymmetrical pattern. The joints frequently affected are the knees, ankles, elbows, wrists, cervical spine, temporomandibular joints (TMJ) and small joints of the hands and feet.
- Rheumatoid factor (RF) positive polyarthritis
RF-positives tend to have more aggressive arthritis. Both large and small joints can be affected and usually occur in a symmetrical pattern. The hips, cervical spine and TMJ may also be affected by inflammation. Rheumatoid nodules may be seen, but are rare in other forms of JIA. The classic symptom in children affected by JIA RF-positive polyarthritis is that adolescent girls present with symmetrical arthritis of the wrists, metacarpophalangeal (MCP) joints, and metatarsophalangeal (MTP) joints.
- Systemic arthritis
Systemic arthritis includes three main symptoms, namely fever, rash, and arthritis. The fever is usually described as prolonged (duration of at least two weeks). Typically, these children appear ill with fever, and this often occurs between febrile episodes. The rash from sJIA is generally described as salmon-colored macules that appear with the fever and disappear when the fever subsides. In some children, the rash may be itchy and resemble atopic dermatitis. It is not uncommon for fever and rash to predate arthritis by many years, making diagnosis difficult. Other manifestations of sJIA include organomegaly, lymphadenopathy, and serositis
- Psoriatic arthritis
Psoriatic arthritis tends to start as monoarthritis and can progress to polyarthritis. The knees, ankles, and small joints of the hands and feet are most commonly affected. Older children with psoriatic arthritis tend to experience more enthesitis. Some patients will experience dactylitis. Their fingers will look swollen and “sausage-like.” On radiography, it is very common to find flexor synovitis.
- Enthesitis-related arthritis
Enthesitis-related arthritis (ERA) is characterized by the presence of enthesitis and/or arthritis. Enthesitis refers to inflammation at the attachment site of ligaments and tendons to bones. In ERA, enthesitis usually occurs in the lower extremities. On examination, the child will feel tenderness or swelling at the attachment of the entheseal to the bone. Arthritis of the hip is also common in ERA. Axial disease and sacroiliitis develop over time. On examination, pain may result from direct pressure on one or both sacroiliac joints. On the modified Schober test, the patient will demonstrate limited forward flexion of the lumbar spine.
The Role of Physiotherapy in JIA Cases
Physiotherapy has a very important role in the management of Juvenile Idiopathic Arthritis (JIA) cases. The role of physiotherapy in cases of JIA is to help minimize symptoms, improve joint function, and improve the quality of life of children affected by this disease. Following are some of the main roles of physiotherapy in JIA cases:
- Maintenance of Movement and Flexibility
A physiotherapist can design an exercise program specifically designed to maintain movement and flexibility of the affected joint. This exercise helps prevent joint stiffness that can occur due to inflammation.
- Relieves Pain
Physical therapists can use physical modalities such as heat, ice, or light massage techniques to help relieve pain and discomfort that a child with JIA may experience.
- Increased Muscle Strength
JIA can cause muscle weakness in some cases because children may be reluctant to move due to the pain. Physiotherapy can help children develop their muscle strength through appropriate exercises.
- Functional Skills
Physiotherapists can assist children in the development of everyday functional skills such as walking, reaching and retrieving objects. This is important because JIA can affect a child's ability to carry out their daily activities.
- Posture Monitoring
Some children with JIA may experience changes in posture due to inflammation of the joints. A physiotherapist can help monitor children's posture and provide advice on how to maintain good posture.
- Education
Physiotherapists also play a role in providing education to children and families about how to manage JIA symptoms, maintain fitness, and maintain consistent physiotherapy treatment at home.
- Tools and Devices Help
In some cases, a physiotherapist can assist in the selection and use of assistive devices or support devices that can help children with JIA better carry out daily activities.
- Collaboration with the Care Team
Physical therapists often work closely with other members of the treatment team, including pediatric rheumatologists, occupational therapists, and nurses, to design a comprehensive treatment plan.
Also read: Kenali Rheumatoid Arthritis
Reference :
- Nadine Saad, Karen Onel. 2020. Overview of Juvenile Idiopathic Arthritis.The Open Orthopaedics Journal. Volume 14. 101-9. doi : http://dx.doi.org/10.2174/1874325002014010101
- Thatayatikom A, Modica R, De Leucio A. Juvenile Idiopathic Arthritis. [Updated 2023 Jan 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554605/
