Still's disease, or juvenile idiopathic arthritis (JIA), is a form of autoinflammatory arthritis that affects children and young adults. It is characterized by periodic bouts of fever and joint pain, as well as other symptoms. Lab findings for Still's disease vary from patient to patient, but typically include an elevated white blood cell count, elevated erythrocyte sedimentation rate (ESR), and elevated levels of C-reactive protein (CRP). A complete blood count (CBC) may also reveal an elevated platelet count or thrombocytosis.
In addition to these laboratory findings, imaging studies such as X-rays or ultrasounds can help to diagnose Still's disease. X-rays can show signs of joint inflammation and erosion in the affected joints, while ultrasounds can reveal fluid accumulation or synovitis (inflammation of the joint lining).
Finally, certain laboratory tests can be used to measure specific autoantibodies associated with Still's disease. These include tests for antinuclear antibody (ANA), rheumatoid factor (RF), and anti-cyclic citrullinated peptide (anti-CCP). A positive test result for any of these markers can help to confirm a diagnosis of Still's disease.
In summary, the laboratory findings for Still's disease include an elevated white blood cell count, elevated erythrocyte sedimentation rate, and elevated levels of C-reactive protein. Imaging studies can reveal joint erosion or synovitis. Certain autoantibody tests such as ANA, RF, and anti-CCP can also help to confirm a diagnosis.