Arthritis is a general term for conditions in which inflammation or other pathological processes affect the joints. The disease can manifest in completely different parts of the body, and the location of the affected joints can be an important clue for a doctor when making a diagnosis, reports the website infohub.kz.
Rheumatologist Sadykhan Dana Valikhanovna said in her social media posts that each type of arthritis has its own "signature." The pattern of joint involvement reflects the underlying mechanisms of each disease.
Gout typically begins with the joint of the big toe. The disease is associated with the accumulation of uric acid in the body and the formation of its crystals in the joints. As the rheumatologist explained, uric acid crystals are more likely to deposit at lower temperatures, so joints farther from the heart are more often affected.
Osteoarthritis more often affects joints that bear significant mechanical stress: the knees, hips, and certain joints of the hands. In this case, the distribution of involvement is related to the load on the joint and gradual changes in its tissues.
Rheumatoid arthritis is characterized by symmetry: for example, the joints of the fingers on both hands may be affected simultaneously. The disease primarily affects the metacarpophalangeal and proximal interphalangeal joints. According to the doctor, this is due to inflammation of the synovial membrane—the inner lining of the joint, which is well represented in these areas.
Psoriatic arthritis, on the other hand, often manifests asymmetrically—for example, inflammation may occur only on one side. In this disease, an entire finger may become inflamed (dactylitis, or "sausage finger"). Additionally, psoriatic arthritis can cause enthesitis—inflammation at the sites where tendons and ligaments attach to bone. Another characteristic area of involvement is the distal interphalangeal joints, located closest to the fingertips.
Thus, the location of the affected joints can provide the doctor with important information about the possible cause of the disease. However, location alone is not sufficient for self-diagnosis—the rheumatologist also considers the nature of the pain, laboratory tests, and examination results.