Systemic Lupus Erythematosus (SLE) is a chronic autoimmune condition where the body’s immune system mistakenly attacks its own healthy tissues and organs. Joint and muscle involvement is one of the most frequent manifestations of SLE, impacting up to 95% of patients over the course of the disease. Musculoskeletal symptoms, including joint pain and inflammation, are often the first sign of the disease, appearing in approximately 50% of people before other issues develop. This common involvement means that joint issues are a significant contributor to disability and a primary concern for those living with the condition.
Primary Joint Targets
Lupus arthritis typically affects multiple joints in a symmetrical pattern, meaning if one joint is affected, the corresponding joint on the opposite side of the body is also often involved. The joints most frequently targeted are the small joints of the hands and wrists. Specifically, the metacarpophalangeal (MCP) joints (connecting the fingers to the hand) and the proximal interphalangeal (PIP) joints (the middle knuckles) are commonly involved.
The wrists are another highly susceptible area, along with the small joints of the feet and toes. While small joints are the most common focus, larger joints can also experience inflammation and pain. These include the knees, ankles, elbows, and shoulders, although they are generally affected less frequently than the hands and wrists. Joint involvement in lupus is often classified as a polyarthritis, referring to pain or inflammation in five or more joints simultaneously. The pattern of affected joints is an important clinical detail used to differentiate lupus from other types of inflammatory arthritis.
Characteristics of Lupus Joint Pain
Lupus-related joint discomfort can manifest in two distinct ways: arthralgia (pain without visible swelling) and arthritis. Arthritis involves objective signs of inflammation, such as swelling, tenderness, stiffness, and sometimes warmth or redness around the joint. Both arthralgia and arthritis are extremely common in SLE patients, with joint pain being a major reason people seek medical attention.
A defining feature of lupus arthritis is its typically non-erosive nature. Unlike conditions such as Rheumatoid Arthritis, the inflammation in SLE rarely causes permanent damage to the bone or cartilage, meaning it does not usually lead to joint destruction. Although newer imaging techniques sometimes detect mild erosions, the general rule is that lupus arthritis is not structurally damaging.
The pain associated with SLE is often described as migratory or intermittent. This means the pain may flare up and then disappear in one joint, only to reappear in a different joint hours or days later. This shifting pattern helps distinguish lupus from other joint diseases. Morning stiffness in lupus is common but is typically shorter in duration compared to other inflammatory arthritides, often lasting only minutes.
Beyond the Joints: Related Musculoskeletal Issues
Musculoskeletal problems in lupus extend beyond the joint capsule itself to involve surrounding tissues. Muscle pain, known as myalgia, is a very frequent complaint, reported by a significant portion of patients. While generalized muscle aches are common, true inflammatory muscle disease, or myositis, is much less frequent, occurring in a small percentage of patients.
Inflammation of the tendons (tendinitis) and the sheaths surrounding them (tenosynovitis) is also a recognized manifestation of SLE. This can affect the movement and function of joints like the elbows, fingers, and shoulders, leading to pain that is often felt outside the joint line. Tenosynovitis, particularly in the hands and wrists, may be more prevalent than previously thought.
Jaccoud’s Arthropathy
A specific and less common manifestation is Jaccoud’s Arthropathy, which develops in a minority of patients (around 3% to 15%). This condition results in non-erosive deformities, such as the fingers bending sideways (ulnar deviation). The deformities are due to laxity and stretching of the ligaments and tendons rather than bone destruction, meaning they are often “reducible” or can be manually straightened.