The main types of synovitis are those found in the presence of lupus, juvenile arthritis, psoriatic arthritis and rheumatoid arthritis. Doctors may also find the condition in connection with tuberculosis, gout, trauma or rheumatic fever, according to HealthCentral.
Synovitis is the inflammation of the cell layer that lines joints, notes Sharecare. In the presence of rheumatoid arthritis, these cells divide and grow while inflammatory cells from elsewhere in the body enter the joint, explains HealthCentral. The joint feels puffy, looks swollen and is warm to the touch from an increase in blood flow. In addition, enzymes released by the cells into the area of the joint increase irritation.
A doctor may suspect the presence of synovitis by physical examination alone, where a joint is readily examinable, such as in the finger. A diagnosis in the case of a deeper joint, such as that of the hip, may require an MRI or possibly even a biopsy, reports Sharecare.