Final answer:
Rheumatoid arthritis and reactive arthritis both involve joint inflammation and can be diagnosed using joint tap. They have different causes, with rheumatoid arthritis being an autoimmune disease and reactive arthritis being a reaction to an infection.
Step-by-step explanation:
Rheumatoid Arthritis
Rheumatoid arthritis (RA) is an inflammatory disorder that primarily affects the synovial joints of the hands, feet, and cervical spine. Affected joints become swollen, stiff, and painful. The disease progresses and can lead to joint deformation, loss of movement, and severe disability.
In reactive arthritis, joint inflammation occurs as a reaction to an infection in another part of the body. The most common infection that triggers reactive arthritis is a bacterial infection in the urinary or gastrointestinal tract. Symptoms of reactive arthritis can vary, but typically include joint pain, swelling, and stiffness.
In both rheumatoid arthritis and reactive arthritis, joint tap can show the presence of inflammation. Joint tap, also known as arthrocentesis, involves inserting a needle into the joint space to collect synovial fluid for analysis. Inflammatory markers, such as increased levels of white blood cells, can be observed in the synovial fluid in both types of arthritis.