Diagnosing and managing lupus-related conditions such as synovitis, myalgia, myositis, tendonitis, osteonecrosis, osteoporosis, joint infection, and fibromyalgia
Joint pain is a very common complaint in people with lupus, and lupus joint pain may lead to difficulty with one’s usual daily activities. A rheumatologist will try to determine the origin of the pain, whether it is in the joint lining (true arthritis), the soft tissues around the joint (due to problems with muscles, tendons, or ligaments), or the bones.
Although joint pain is usually due to lupus itself, it may also be due to medication complications or an associated rheumatologic condition. Once the cause is determined, the proper treatment can be prescribed.
During the course of their disease, approximately 95% of lupus patients will have joint symptoms − either arthritis or arthralgias. Arthritis in lupus is due to inflammation of the lining of the joint (called synovitis) that leads to swelling, tenderness, and stiffness. Arthralgia refers to joint pain without swelling.
Lupus arthritis has many similarities − but also differences − with rheumatoid arthritis (RA). In both cases, small joints are usually affected in a symmetric distribution (for example, both wrists and/or hands affected at the same time). Lupus arthritis, however, is typically not as severe as RA, as it causes less swelling, shorter periods of morning stiffness, and only rarely causes bone erosions (holes in the bones around the joint). The symptoms of lupus arthritis are also often of shorter duration (days) and may migrate, or change location, from one joint to another.
In some patients with lupus arthritis, there are significant deformities (misalignment of the bones) of the joints, mainly affecting the fingers. Characteristically, the fingers deviate towards the direction of the little finger and become bent in such a way that they resemble the neck of a swan, called “swan neck deformities.” Although the deformities in lupus are similar in appearance to those occurring in RA, they are usually not due to bone damage but instead to ligament and tendon laxity, and therefore are easily “correctable” with external pressure. This condition is called “Jaccoud arthropathy” and usually happens in patients with longstanding disease.
A small minority of patients can develop arthritis that looks remarkably similar to RA, and notably results in the formation of erosions. These lupus patients may have a positive anti-CCP antibody, which is a test often used to diagnose RA. When this occurs, this condition is sometimes called “rhupus.” It is still not clear whether “rhupus” represents an overlap of RA and lupus, or simply another form of lupus.
Lupus arthritis is often first treated with nonsteroidal anti-inflammatory medications (NSAIDS), such as ibuprofen or naproxen. Hydroxychloroquine, an antimalarial medication, is typically prescribed for all patients with lupus at the time of diagnosis and is particularly effective in improving joint symptoms. However, it may take two to three months to work.
If the patient does not have a good response or there are contraindications to the use of these medications, short courses of low-dose glucocorticoids (5mg to 10mg of prednisone) may be used. Additionally, antimalarial medications (hydroxychloroquine) and other disease-modifying antirheumatic drugs (DMARDs) such as methotrexate or azathioprine may be used to treat more severe or persistent arthritis.
Rituximab, belimumab, and anifrolumab are additional therapeutic options available to treat difficult lupus arthritis cases. The rheumatologist will decide which treatments are most appropriate on a case-by-case basis depending on whether other organs are also affected by lupus.
Patients with lupus may also experience pain that does not originate in the joint itself, but rather in the muscles (myalgia and/or myositis) or tendons (tendonitis or tenosynovitis) around the joint.
Pain in the muscles (myalgia) is a common symptom in lupus patients. The upper arms and thighs are the most frequently involved areas. In some cases, the pain is accompanied by muscle weakness, which is known as myositis. In this case, blood tests measuring muscle enzymes, such as creatine kinase (CK), are elevated, indicating muscle injury, and the condition is managed similarly to dermatomyositis or polymyositis. Of note, when used at high and prolonged doses, glucocorticoids may cause muscle weakness. Rarely, exposure to antimalarial medicines for many years may also cause muscle weakness.
Tendonitis (also written as tendinitis) refers to inflammation of the tendons (fibrous tissue that connects muscles to the bones). This condition is also relatively common in people who have lupus and may affect the elbow (epicondylitis, also known as tennis elbow), shoulder (rotator cuff), or heel (Achilles tendonitis or plantar fasciitis). Tearing of the tendons rarely occurs. Of note, tendon pain is often due to overuse, a common condition in the general population, and not necessarily due to lupus.
Most cases of myalgia and tendonitis will respond to rest, physical therapy, and treatment with NSAIDs or low-dose glucocorticoids. Injections of glucocorticoids or surgery may be required in more difficult cases of tendonitis. In contrast to myalgia, lupus-related myositis typically requires more intensive therapy, with high doses of glucocorticoids with or without DMARDs.
Glucocorticoids are often called “miracle” drugs because they work quickly (within 8 to 24 hours) to control the inflammation and pain in lupus-related arthritis, tendonitis, and myositis. However, the prolonged use of high doses of glucocorticoids can cause significant bone and muscle damage, as well as other complications. Therefore, rheumatologists use glucocorticoids mostly in the acute setting to achieve rapid control of inflammation, while waiting for other immunosuppressive drugs to take effect, usually within one to three months. As soon as the disease process is under control, glucocorticoids are typically tapered to low doses (for example, prednisone doses below 7.5mg/day), or, if possible, completely off.
Not all joint pains are due to lupus. Other causes of pain that need to be considered include osteonecrosis, osteoporotic bone fractures, septic arthritis, and fibromyalgia.
Osteonecrosis (also known as avascular necrosis or AVN) refers to the “death” of bone tissue (bone necrosis). Long-term use of high doses of glucocorticoids is associated with an increased risk of developing osteonecrosis. Depending on its severity, osteonecrosis may cause no symptoms at all or cause significant joint pain and sometimes collapse of the affected bones. The most commonly involved joints are the hips, which results in pain in the groin especially with weightbearing activities like walking, followed by the knees and shoulders. When osteonecrosis progresses, pain can occur at rest, often at night. The diagnosis can be made by a plain X-ray. However, in early stages, an MRI is necessary to make the diagnosis.
Patients with early stages of osteonecrosis may benefit from conservative therapy, including pain medication and limited weightbearing. Core decompression surgery of the hip may also be considered. In more advanced cases, such as those with hip bone collapse, joint replacement surgery (arthroplasty) is required.
Osteoporosis (weakening or thinning of the bone) may occur in patients with lupus due to either the disease itself or the medications used to treat it (especially glucocorticoids). (Learn more about the relationship between lupus and osteoporosis.)
Osteoporosis increases the risk of fractures, particularly of the spine and the hip. When a vertebral (spine) fracture occurs, for example, patients usually complain of sudden pain in a localized area of the spine, sometimes after only minimal trauma. X-rays can show the fracture as a compression (loss of height) of a vertebra, though an MRI may be necessary for subtle cases.
The best therapy is prevention. Lupus patients, especially those on glucocorticoids, should have a bone mineral density test (known as a DEXA or DXA) to assess their bone status, engage in weightbearing activities (such as walking), and optimize their intake of calcium and vitamin D.
In people with established osteoporosis, or at high risk for osteoporosis due to treatment with high and prolonged (that is, for more than three months) doses of glucocorticoids, a potent anti-osteoporosis agent such as a bisphosphonate will also be needed for extra protection, unless there is a contraindication.
Pain medications and spine braces may be used in the short term for the pain of osteoporotic vertebral fractures. Nasal calcitonin may also be helpful. Vertebroplasty or kyphoplasty, two procedures where bone cement is injected into the fractured vertebra, may also be considered to control acute pain and deformity due to a vertebral compression fracture. Hip fractures require surgery.
Septic arthritis, or joint infection, is a medical emergency and requires prompt diagnosis and therapy. Despite the fact that people with lupus take medication that “lower” the immune system and therefore make it easier for an infection to occur, septic arthritis is relatively rare in lupus.
Aspiration (extraction) of synovial fluid from the joint is performed along with blood tests. Once the causative bacterial strain is identified, antibiotic drugs are prescribed accordingly. In most cases, surgery is required for “cleaning” the joint.
Fibromyalgia is a chronic condition of widespread pain and fatigue. It can exist by itself or accompany other diseases such as lupus. While the cause of fibromyalgia remains unclear, it is not due to active inflammation from lupus and therefore no extra immunosuppressive treatment is required.
Management is often difficult and requires full commitment by the patient. Treatments often differ among patients, and usually more than one therapy is required. Some commonly used treatments include aerobic exercise, efforts to improve sleep, cognitive-behavioral therapy, and prescription medications. It is also imperative to determine which symptoms may be caused by lupus versus which are caused by fibromyalgia, since the treatments for the two are different.