Juvenile idiopathic arthritis (JIA) describes a group of arthritic conditions affecting children through age 17. JIA is characterized by joint pain and tenderness, swelling and stiffness lasting more than six weeks. Seven subtypes of JIA include systemic arthritis; oligoarthritis; polyarthritis, rheumatoid factor negative; polyarthritis, rheumatoid factor positive; psoriatic arthritis; enthesitis-related arthritis; and undifferentiated arthritis. Each JIA subtype has different characteristics and symptoms.
Joint Pain and Tenderness
Joint pain and tenderness are defining symptoms of all subtypes of JIA. Tenderness is elicited by putting hand pressure on the affected joint. The feet, hands and knees are often affected, although other joints may also be involved. The various JIA subtypes involve a differing number of joints, explains the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Oligoarthritis affects one to four joints. Polyarthritis involves five or more joints. The other subtypes affect a variable number of joints. Pain typically limits a child's use of the affected joints. Limping or refusal to use an affected hand or arm is common among children with JIA.
Joint Stiffness
Similar to adult forms of arthritis, periods of sleep or inactivity cause stiffness in the joints affected by JIA. Cedars-Sinai Medical Center points out that children are often most stiff in the morning, or after waking up from a nap.
Joint Swelling and Redness
The joints affected by JIA are characteristically swollen. The skin over the involved joints is typically red and warm to the touch. During periods of remission when the disorder is quiescent, joint swelling and redness resolve.
Fever
Fever is a defining characteristic of systemic arthritis. NIAMS explains that an intermittent fever of at least two weeks duration with a spike lasting at least three days are required to make a diagnosis of systemic arthritis. Approximately 20 percent of children with JIA have the systemic form, according to the American Academy of Orthopaedic Surgeons. Fever is not a typical characteristic of other forms of JIA.
Skin Rash
Skin rash is characteristic of systemic and psoriatic JIA. Rash associated with systemic arthritis usually accompanies the fever. In contrast, children with psoriatic arthritis usually have typical red, raised areas of skin encrusted by silvery-white scales that define psoriasis. Rash is not a symptom of the other subtypes of JIA.
Muscle Weakness
Because JIA limits motion due to pain, the muscles around an affected joint may begin to wither, a condition called muscle atrophy. As the muscles shrink, the affected area becomes increasingly weak. Children with any form of JIA may develop this symptom.
References
- Arthritis Foundation: Juvenile Rheumatoid Arthritis
- Mayo Clinic: Juvenile Rheumatoid Arthritis, Symptoms
- American Academy of Orthopaedic Surgeons: Juvenile Arthritis
- Cedars-Sinai Medical Center: Juvenile Rheumatoid Arthritis
- National Institute of Arthritis and Musculoskeletal and Skin Diseases: Juvenile Arthritis
