In which type of arthritis does uric acid accumulate in the joints?

Gout is characterized by the accumulation of uric acid in the joints, leading to sudden and severe episodes of pain, swelling, and redness. This condition arises when there is an excess of uric acid in the bloodstream, often due to overproduction or insufficient elimination by the kidneys. The excess uric acid can crystallize and deposit in the joints, commonly affecting the big toe, which is often the site of intense inflammation during a gout attack.

In contrast, the other forms of arthritis mentioned—rheumatoid arthritis, osteoarthritis, and psoriatic arthritis—do not primarily involve uric acid buildup. Rheumatoid arthritis is an autoimmune condition characterized by joint inflammation and systemic symptoms. Osteoarthritis is a degenerative joint disease that results from the wear and tear of cartilage. Psoriatic arthritis is associated with psoriasis and involves inflammation in the joints and possibly the skin but does not specifically involve uric acid accumulation. Therefore, gout is distinctly identified by the role of uric acid in its pathology, making it the correct choice in this context.