Q: My family doctor, suspecting I might have lupus, referred me to a rheumatologist, who diagnosed fibromyalgia. Is it possible to have symptoms of lupus, but actually have fibromyalgia?

A: Figuring out whether a patient has lupus, fibromyalgia or both – which is entirely possible – requires a thorough medical history, physical examination and laboratory tests. Diagnosing lupus and fibromyalgia can be difficult because the conditions share some symptoms.

During the medical history, fibromyalgia patients usually describe fatigue and a generalized muscle pain or soreness of the muscles that often is made worse by lack of quality sleep. Lupus patients may also have fatigue and muscle soreness, but initial symptoms may include a rash across the cheeks and nose that gets worse in sunlight, kidney problems, difficulty breathing or a blood clot, stroke or heart attack.

Physical examination of a person with fibromyalgia shows joints that move normally and are not swollen. However, people with fibromyalgia usually have tender areas over muscles, and pressing those areas causes discomfort. The examination of a person with lupus may reveal joint pain, stiffness, swelling or abnormal movement.

In most cases, a patient's history and physical examination lead to a diagnosis; lab tests usually confirm the diagnosis. A blood test that measures the level of antinuclear antibody (ANA) usually is positive in people who have lupus, but it also can be positive in those with mixed connective tissue disease, rheumatoid arthritis (RA), scleroderma and Sjögren's syndrome. Therefore, a rheumatologist will run several other special tests to confirm lupus. In people with fibromyalgia, all blood tests usually are normal.

A proper diagnosis is important because the treatments for lupus and fibromyalgia are different. When a person has both fibromyalgia and lupus, corticosteroids or disease-modifying anti-rheumatic drugs (DMARDs), such as methotrexate, should be prescribed to prevent lupus-related damage to the internal organs. Physical therapy, counseling and antidepressant medications can help improve muscle aches, sleep and mood changes associated with fibromyalgia

Robert Shaw, MD, Rheumatologist