How Lupus Affects the Muscles, Tendons, and Joints
A healthy immune system helps your body fight off infection from viruses, bacteria, and other foreign substances. Lupus is an autoimmune disease, which means it causes the immune system to attack your own body tissue, such as your muscles, joints, and connective tissue. The damage from lupus can trigger pain and inflammation of these body tissues.
Pain and inflammation are common in people with lupus. More than 90 percent of people with the condition will feel joint pain at some point in their illness – joint pain is the reason many go to the doctor in the first place. In fact, more than half of all people with lupus say that joint pain was their first symptom, according to the National Resource Center on Lupus.
About half of all people with lupus experience muscle pain and weakness, especially during flare-ups that make symptoms worse. Muscle pain (myalgia) and muscle inflammation (myositis) of muscle groups can cause weakness and loss of muscle strength. These symptoms may be the result of inflammation (swelling), muscle atrophy (weakness),
Treatment for these symptoms will vary according to their location and the underlying cause. To provide the best treatment possible, doctors will often refer patients with lupus to rheumatologists, who are physicians who specialize in diagnosing and treating conditions affecting the joints, muscles, tendons, bones, and other connective tissues. Rheumatologists can also determine the underlying causes of lupus symptoms.
Reasons Symptoms of Lupus Occur
Inflammation is the body’s natural immune response to infections, damage to cells, exposure to toxins, or other harmful stimuli. Injured cells trigger the release of chemicals that increase blood flow to the affected area, which causes swelling and redness. These chemicals also cause fluid to leak into the affected area, which also causes swelling.
Because lupus causes the immune system to attack your own body tissue instead of harmful stimuli, inflammation may affect otherwise healthy tissue. Inflammation can cause pain, joint stiffness, and other symptoms of lupus.
Arthritis is swelling and tenderness of the joints. Lupus is not a type of arthritis, but lupus can cause symptoms of arthritis, such as pain, swelling, stiffness, warmth, and tenderness in your joints. Lupus typically affects the joints farthest from the middle of the body, such as your fingers, wrists, elbows, toes, ankles, and knees. Stiffness is usually worse when you wake up, but improves gradually throughout the day. Arthritis from lupus usually involves more than one joint, and the associated inflammation is usually symmetrical, which means it tends to affect the same joints on both sides of your body. About 95 percent of people with lupus will develop arthritis or joint pain at some point, according to Johns Hopkins Lupus Center.
Arthritis associated with lupus is different from other destructive forms of arthritis, such as rheumatoid arthritis (RA), which can cause bones to wear away. Fewer than 10 percent of people with lupus may develop deformity in their hands, however, especially if there is looseness in the connective tissue holding the joints of the hands together.
Myositis is a condition in which inflammation of the skeletal muscles results in weakness. Injury, infection, or an autoimmune disease, like lupus, can cause myositis. In fact, many people with lupus also have myositis.
Myositis associated with lupus can cause the muscles of your neck, shoulders, arms, upper pelvis, and thighs to weaken. In the early stages, loss of strength in these muscles can make it difficult to rise from a chair or climb stairs. Later, the overlapping conditions can make it hard to lift your arms to comb or brush your hair, place objects on a shelf, or get out of a bathtub. In severe cases, myositis can make it challenging to raise your head or turn over in bed.
Fortunately, it is possible to regain muscle strength and function through exercise. Your physical therapist can develop and supervise an exercise program to help keep your muscles strong.
Drug-induced muscle weakness
Certain medications used to treat lupus and related conditions can cause side effects, such as muscle weakness. These medications include prednisone and other corticosteroids, drugs to lower cholesterol, and hydroxychloroquine (Plaquenil®). If you are experiencing muscle weakness and are taking any prescription drugs, consult with your physician before changing how you take any medication. Your doctor can run lab tests that measure muscle enzymes, review your medications to determine the underlying cause of your muscle weakness, and adjust your medication accordingly.
Tendonitis and bursitis
Lupus can affect tendons, which are the tough fibers that attach your muscles to your bones. The condition can also affect bursae, which are small sacs containing a slippery fluid that lubricates the muscles, bones, and tendons that move your joints. Specifically, lupus can cause inflammation of your tendons and bursae to cause tendonitis and bursitis, which can result in joint pain and stiffness. Inflammation can also cause inflammation of the synovial membrane, which lines the joints, tendons, and bursae. Tendonitis and bursitis associated with lupus most commonly affect the shoulders, elbows, and fingers.
Carpal tunnel syndrome
Carpal tunnel syndrome is a condition in which pressure on a nerve in your wrist causes pain, tingling, and numbness in your fingers and parts of your hand. Lupus can cause inflammation and pressure on this nerve to create carpal tunnel syndrome.
Lupus affects many parts of the body, including muscles, tendons, and joints, to cause pain and stiffness. In some cases, lupus can cause long-term damage to these areas of the body.