Idiopathic Juvenile Idiopathic Arthritis (JIA)
One of the most common and complex pathologies we expertly manage is Juvenile Idiopathic Arthritis (JIA). This chronic inflammatory disease, specific to the pediatric age group, requires a deep understanding and a dedicated medical team to ensure mobility, comfort and improved quality of life for young patients.
What is Idiopathic Juvenile Idiopathic Arthritis (JIA)?
Idiopathic Juvenile Idiopathic Arthritis (JIA) is a chronic condition characterized by persistent inflammation of the joints. The term 'idiopathic' emphasizes the fact that the exact cause of the disease currently remains unknown. 'Juvenile' refers to the onset of symptoms, which usually occurs before the age of 16. Typical manifestations of joint inflammation include pain, swelling and limitation of movement.
It is important to understand that JIA is not a single disease, but a group of seven distinct conditions, categorized according to the number of joints affected, the systemic symptoms present and the results of laboratory tests during the first six months of the disease. This classification helps rheumatologists at Elytis Hospital to personalize the therapeutic approach for each child.
Why is it considered a chronic disease?
A disease is defined as chronic when adequate treatment does not lead to complete cure, but rather to improvement in symptoms and laboratory test results. In the case of Juvenile Idiopathic Arthritis (JIA), this means that, at the time of diagnosis, it is difficult to predict the duration of the disease.
How common is Idiopathic Juvenile Idiopathic Arthritis (JIA)?
JIA is considered a relatively rare disease, affecting about 1-2 in 1,000 children. Although it is not a widespread condition, its impact on the quality of life of a child and his or her family can be significant, highlighting the importance of early diagnosis and specialized care.
What causes Idiopathic Juvenile Idiopathic Arthritis (JIA)?
Although the exact cause of JIA remains unknown, research indicates that it is an abnormal immune system response. Normally, the immune system protects the body from infection by distinguishing foreign cells from its own. In Idiopathic Juvenile Idiopathic Arthritis (JIA), it is thought that the immune system mistakenly attacks its own tissues, particularly the synovial lining of the joints, leading to inflammation. For this reason, JIA is classified as an autoimmune disease.
Genetic factors also play a role, although JIA is not a hereditary disease in the direct sense. Certain genetic predispositions, still largely unknown, may increase an individual's susceptibility to develop the disease in combination with environmental factors, possibly infections. It is rare for two children from the same family to develop JIA.
How is Idiopathic Juvenile Idiopathic Arthritis (JIA) diagnosed?
The diagnosis of JIA is a complex process that is based on the presence and persistence of arthritis, along with careful exclusion of other conditions:
- Detailed history: Collecting information about the child's medical history and onset of symptoms.
- Complete physical examination: evaluate joints for signs of inflammation (pain, swelling, limitation of movement) and look for other manifestations.
- Specific laboratory tests: blood tests to identify inflammatory markers, rheumatoid factor (RF), antinuclear antibodies (ANA) and HLA-B27, which can help classify the subtype of JIA and assess the risk of complications such as uveitis.
- Modern imaging techniques: X-rays, joint ultrasound and nuclear magnetic resonance imaging (MRI) can be used to assess the condition of the joints and to rule out other causes of symptoms.
- Eye exam: A slit-lamp examination is essential for early detection of uveitis, a common ocular complication in certain forms of JIA.
The diagnosis of JIA is established if the onset is before the age of 16 years, the arthritis lasts for more than 6 weeks and all other possible causes of arthritis have been ruled out. The 6-week period is crucial in differentiating JIA from transient arthritis that can occur following infections.
What happens to the joints in Juvenile Idiopathic Arthritis (JIA)?
Normally, the synovial membrane surrounding the joint is thin. In Idiopathic Juvenile Idiopathic Arthritis (JIA), this membrane thickens significantly and becomes infiltrated with inflammatory cells and tissue, producing an excessive amount of synovial fluid within the joint. This process leads to swelling, pain and limited movement.
A characteristic symptom of joint inflammation is stiffness, which is more pronounced after long periods of rest, especially in the morning (morning stiffness). Children with JIA may adopt analgesic positions, keeping the joint in a semi-flexed position to reduce pain. If this position is maintained for long periods, it can lead to shortening of muscles and tendons and flexion deformities.
Untreated chronic inflammation can cause joint damage through two main mechanisms: thickening of the synovial membrane (synovial pannus formation) and the release of substances that erode joint cartilage and bone, visible on X-rays as bone erosions. Long-term maintenance of the joint in an antalgic position can also lead to muscle atrophy and soft tissue retraction, contributing to deformities.
Different types of Idiopathic Juvenile Idiopathic Arthritis (JIA)
Classifying JIA into different subtypes is essential to guide treatment and understand prognosis:
- Systemic JIA: Characterized by arthritis associated with systemic symptoms such as prolonged high fever, rash, enlargement of the liver, spleen or lymph nodes and inflammation of the serosa (pericarditis, pleuritis). Arthritis may occur at onset or later and usually affects 5 or more joints.
- Polyarticular JIA: Affects 5 or more joints in the first 6 months of disease, without systemic fever. It is distinguished according to the presence or absence of rheumatoid factor (RF positive or negative). The RF-positive form is rare in children and is similar to adult rheumatoid arthritis.
- Oligoarticular JIA: The most common subtype, affecting less than 5 joints in the first 6 months, usually the large joints of the lower limbs (knees, ankles). It is subdivided into persistent (less than 5 joints affected throughout the disease) and extensive (number of joints affected increases to 5 or more). This form carries an increased risk of uveitis.
- Psoriatic Arthritis: Arthritis associated with psoriasis (skin condition with scaly plaques) or a family history of psoriasis. Suggestive signs include dactylitis (sausage fingers) and nail changes.
- Arthritis Associated with Enthesitis: Characterized by arthritis mainly affecting the large joints of the lower limbs and enthesitis (inflammation of the insertion points of tendons on the bone). Heel pain is common. May be associated with acute anterior uveitis and HLA-B27 positivity.
Diagnosis and treatment
At Elytis Hospital, we approach the treatment of Juvenile Idiopathic Arthritis (JIA) through a personalized and multidisciplinary strategy, with the main goal:
- Relieve pain, fatigue and stiffness.
- Prevent damage to joints and organs.
- Minimize deformation.
- Improve mobility and joint function.
- Maintain normal growth and development.
Our team includes expert pediatric rheumatologists, orthopedic surgeons, physiotherapists and ophthalmologists, who collaborate to provide comprehensive care. Treatment strategies include:
- Nonsteroidal anti-inflammatory drugs (NSAIDs): used to reduce pain and inflammation.
- Intra-articular Corticosteroid Injections: Effective for rapid control of inflammation in affected joints.
- DMARDs: Methotrexate is the first-line drug used to control disease progression and reduce inflammation in the long term. Other DMARDs include leflunomide and sulfasalazine.
- Biologic Agents: Advanced drugs that target specific molecules involved in the inflammatory process (anti-TNF, anti-IL-1, anti-IL-6, T-cell inhibitors) These have revolutionized the treatment of JIA, providing better disease control and reducing the risk of joint damage.
- Rehabilitation and Physical Therapy: Essential for maintaining mobility, muscle strength and joint function. Includes therapeutic exercises, orthotics and occupational therapy.
- Orthopedic Surgery: may be necessary in cases of severe joint destruction (joint prostheses) or contractures (surgical releases).
- Regular Ophthalmologic Monitoring: Crucial for early detection and treatment of uveitis, preventing severe complications.
At Elytis Hospital, we understand the emotional and physical impact that Juvenile Idiopathic Arthritis (JIA) can have on children and their families. We are committed to providing not only high-quality medical treatment, but also emotional support, education and counseling. Our aim is to restore mobility, security and confidence in their own bodies so that every child can fully enjoy life.
Latest medical review:
03.06.2025, Dr. Ana Karina Gîlcă - Specialist in Rheumatology, Dr. Claudia Ruginosu - Primary Physician in Pediatrics
References:
- "What you need to know about juvenile arthritis: causes, symptoms, treatment". Dr.Max, 2022.
- Stefan, Mariana (Dr.) "Juvenile idiopathic arthritis - what parents need to know". Regina Maria, 2014.