什麼是兒童特發性關節炎 (JIA)？
怎麼判斷？留意 6 大警示症狀
為什麼我的孩子會得這種病？
確診了怎麼辦？
結語
掛號請按我
When a Child Complains of Joint Pain, It’s Not Always “School Avoidance”: A Comprehensive Guide to Juvenile Idiopathic Arthritis (JIA) — Symptoms, Diagnosis, and Treatment
Author: Chi-Teng Tseng, MD
Sunshine (nickname), a sixth-grader and an avid soccer player, woke up one morning to find his right knee abnormally swollen and painful. The pain was so severe that he could not get out of bed and return to the soccer field he loved. Along with a fever, he was initially taken to an orthopedic clinic, where the physician, sensing something was wrong, referred him to a hospital.
At first, it was treated as septic arthritis. However, despite draining the joint fluid and administering antibiotics, his knee failed to return to its pre-illness state. Instead, the swelling and pain recurred persistently—particularly during weather changes or in the early morning—sometimes accompanied by unusual symptoms like eye redness. After three months of seeking help from various specialists, including orthopedics, rehabilitation, and traditional medicine, he eventually arrived at our department.
If your child consistently complains of joint pain, exhibits an unusual gait, or suffers from an unexplained fever, do not simply dismiss it as "growing pains" or a sports injury. It could be the most common chronic rheumatic disease in children: Juvenile Idiopathic Arthritis (JIA).
What is Juvenile Idiopathic Arthritis (JIA)?
Juvenile Idiopathic Arthritis (JIA) refers to chronic joint inflammation that begins before the age of 16, persists for more than six weeks, and the physician makes the diagnosis after excluding other causes such as infection, malignancy, or trauma.
Is it common in Taiwan? Approximately 15~30 out of every 100,000 children in Taiwan are affected.
Key Point: This is an autoimmune disease. The immune system mistakenly attacks the body's own joints, unlike the "wear and tear" osteoarthritis typically seen in the elderly.
How to Identify It? Watch for These 6 Red Flags
If you observe the following symptoms in your child, please seek consultation from a Pediatric Allergist, Immunologist, and Rheumatologist as soon as possible:
Joint Swelling and Pain: Swelling or pain in a single joint or multiple joints.
Morning Stiffness: Stiffness and lack of flexibility in movements upon waking or after sitting for long periods, often described as moving like a "robot."
Abnormal Gait: Limping or changing walking posture to avoid pain.
Localized Heat: The inflamed joint feels warmer to the touch than the surrounding skin.
Limited Mobility: A reluctance to run or jump, or an inability to complete certain physical movements.
Unexplained Fever and Rash: A fever lasting more than 10 days with no clear cause, often accompanied by a faint salmon-pink rash (common in Systemic JIA).
Note: JIA-related inflammation typically involves swelling, pain, and heat, but rarely presents with significant redness.
Why Did My Child Develop This Condition?
This is a question that brings much self-blame to many parents. Please rest assured: this is not due to any lapse in care or dietary choices.
Causes: The exact cause remains unknown. It is believed to be triggered by a combination of "genetic predisposition" and "environmental factors" (such as infections) that lead to immune system dysregulation.
Mechanism: Immune cells attack the synovial membrane of the joints, causing inflammation and fluid accumulation. If left untreated, it can eventually erode cartilage and bone.
JIA is an umbrella term encompassing several subtypes, each requiring a different therapeutic strategy. Beyond arthritis, children with JIA may also experience unexplained fevers, uveitis (eye inflammation), rashes, hepatosplenomegaly (enlargement of the liver and spleen), lymphadenopathy, and in severe cases, life-threatening Macrophage Activation Syndrome (MAS).
What Happens After Diagnosis?
The good news is that JIA is treatable. In the past, treatment was limited to anti-inflammatory drugs, steroids, and certain immunosuppressants, which could lead to cumulative side effects over time. Today, medical advancements have introduced many highly effective treatments with fewer side effects. The goal is to control inflammation, eliminate pain, and prevent joint deformity.
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): First-line treatment to relieve swelling, heat, and pain.
Intra-articular Steroid Injections: Direct injection into a single inflamed joint, providing rapid relief with fewer systemic side effects.
Conventional Disease-Modifying Antirheumatic Drugs (cDMARDs): Such as Methotrexate (MTX), these are the cornerstone of treatment and help regulate the immune system.
Biologics: A major breakthrough in recent years. When conventional drugs are insufficient, biologics (e.g., Enbrel, Humira, Actemra) can precisely block inflammatory factors, significantly improving outcomes.
Note: Screening for Hepatitis B/C and latent tuberculosis is required before use.
Small Molecule Drugs (JAK Inhibitors): Another recent breakthrough. Unlike biologics that require periodic injections, these are taken orally daily, reducing distress for the child. They precisely block inflammatory pathways to lower the risk of joint destruction.
Note: Screening for Hepatitis B/C and latent tuberculosis is required. Monitoring of blood counts, liver function, and lipid levels is necessary during use, with attention to the risk of herpes zoster (shingles).
Conclusion
It is natural for parents to feel anxious when their child faces a chronic illness. However, with modern medical progress, "early diagnosis and proactive treatment" allow the vast majority of children to avoid joint deformities and enjoy a happy childhood and a bright future. If you suspect your child has related symptoms, please consult a specialist in pediatric allergy, immunology, and rheumatology promptly.
