Section 5. Bone, Joint, and Muscle Disorders

Chapter 74. Disorders of Muscles, Bursas, and Tendons

Topics: Introduction | Muscle Cramps | Fibromyalgia | Bursitis | Tendinitis and Tenosynovitis | De Quervain's Syndrome | Baker's Cysts

Fibromyalgia

Fibromyalgia describes several disorders, all characterized by achy pain and stiffness in soft tissues, including muscles, tendons, and ligaments.

The term fibromyalgia is used to describe several related disorders. Various alternative terms for these disorders have been used, including generalized fibromyalgia, primary fibromyalgia syndrome, secondary fibromyalgia syndrome, localized fibromyalgia, and myofascial pain syndrome, each having different connotations. Previously, these disorders were collectively called fibrositis or fibromyositis syndromes, but because inflammation is not present, the "itis" suffix was dropped.

In generalized fibromyalgia, which is about 7 times more common in women than in men, the pain and stiffness are widespread, occurring throughout the body. Primary fibromyalgia syndrome is the most common variation of generalized fibromyalgia; it usually occurs in young or middle-aged women who have no associated or contributing underlying disorder.

Secondary fibromyalgia syndrome is a type of generalized fibromyalgia and refers to fibromyalgia symptoms in a person who has another underlying disorder that is causing the fibromyalgia symptoms, such as hypothyroidism. Other disorders, such as systemic lupus erythematosus or rheumatoid arthritis, may be associated with fibromyalgia, but not be the underlying cause.

In localized fibromyalgia, pain and stiffness occur in a particular area, or at a few sites, such as the jaw, neck, and/or shoulder muscles. Localized fibromyalgia is somewhat more likely to occur in men, possibly because they are more likely to engage in more physically muscular activities in occupational or sports situations. Sometimes, localized fibromyalgia gradually spreads to become generalized fibromyalgia. Myofascial pain syndrome is a type of localized or regional fibromyalgia which may occur in various sites. In the temporomandibular type (see Section 8, Chapter 116), the chewing muscles on the side of the face are commonly involved and may become painful and tender.

Fibromyalgia is not dangerous or life threatening. Nonetheless, persistent symptoms can be very disruptive.

Causes

Usually, the cause of generalized fibromyalgia is unknown; in primary fibromyalgia syndrome, the cause is always unknown. However, generalized fibromyalgia may be worsened by physical or mental stress, poor sleep, repetitive strains, an injury, or chronic exposure to dampness and cold. In secondary fibromyalgia syndrome, an underlying cause is known. The syndrome may occur as a complication of certain infections (for example, Lyme disease), or hypothyroidism. Another associated disorder, such as rheumatoid arthritis or systemic lupus erythematosus, may be coincidental or may sometimes increase the symptoms of fibromyalgia.

Localized fibromyalgia often results from an occupational or recreational muscle strain. The temporomandibular type of myofascial pain syndrome can be caused by clenching and grinding of the teeth, especially while the person is asleep.

Symptoms

Aching stiffness and pain usually develop gradually in generalized fibromyalgia. In localized fibromyalgia, the pain may begin more suddenly after muscle strains, and be sharp. In both syndromes, the pain usually worsens with fatigue, straining, or overuse. Specific discrete areas of muscle may be tender when firm fingertip pressure is applied; these areas are called either tender or trigger points. (Both points are tender, but "trigger" points radiate the pain to a distant site.) During flare-ups, muscle tightness or even spasms may occur. Any soft tissue (muscles, tendons, and ligaments) may be affected. Soft tissue of the neck, shoulders, chest and rib cage, lower back, and thighs as well as joints are especially likely to be painful.

In primary fibromyalgia syndrome, widespread pain typically occurs and is often accompanied by other symptoms, such as poor sleep, anxiety, depression, fatigue, and irritable bowel syndrome (see Section 9, Chapter 129).

In the temporomandibular type of myofascial pain syndrome, the mouth often cannot be opened fully, and opening the mouth may be painful. Clenching or grinding of the teeth during sleep can lead to a headache on awakening that improves over the course of the day. Sometimes the teeth clenching or grinding continues throughout the day.

Diagnosis and Treatment

The diagnosis of fibromyalgia is based on the pattern and location of the pain as well as the presence of tender points. Doctors firmly press designated areas of the body to determine whether the person feels pain in one spot (a tender point) or whether the pain seems to travel (refer) to another area (a trigger point). Diagnosis requires tenderness at 11 or more of the 18 designated tender points.

See the figure Fibromyalgia: Finding the Tender Points.

Nondrug treatments are usually the most helpful. Reducing stress can alleviate some mild cases of fibromyalgia. Stretching and conditioning exercises of gradually increasing intensity, improvements in the quality of sleep, application of heat to the affected area, gentle massage, and keeping warm are usually beneficial.

Aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) are generally of limited benefit. Occasionally, local anesthetics (eg, lidocaine, alone or with corticosteroids [eg, hydrocortisone]) are injected directly into a particularly tender area or trigger point, but these injections should not be relied on for repetitive use. Doctors may prescribe low doses of tricyclic antidepressants (see Section 7, Chapter 101) 1 or 2 hours before bedtime, which are prescribed to improve sleep rather than to relieve depression.

For people who have the temporomandibular type of myofascial pain syndrome, using a plastic mouth guard can keep the teeth from touching each other and thereby prevent them from clenching and grinding. A benzodiazepine or tricyclic antidepressant at bedtime is sometimes used to relieve symptoms until a mouth guard can be obtained. Nonsteroidal anti-inflammatory drugs (NSAIDs) or acetaminophen is useful. Because the condition tends to persist, opioids should not be used, except possibly for short times. The person should be taught to stop clenching the jaw and grinding the teeth. Foods that are hard to chew and chewing gum should be avoided. Physical therapy, biofeedback to encourage relaxation, and psychologic counseling help some people. Most people, even if untreated, stop having significant symptoms within 2 to 3 years.