Fibromyalgia and Lyme disease: one often mistaken for the other

Healthfacts, Oct, 1992

Many people seeking treatment for and being diagnosed as having Lyme disease actually have an arthrifis-llke ailment called fibromyalgia, according to a news release from the American College of Rheumatology. Two new studies showing the extent of misdiagnosis were presented this month at the College's annual meeting.

Lyme disease was first recognized over 17 years ago when several children living in Lyme, Connecticut, developed what was initially thought to be rheumatoid arthritis. The disease is caused by a coiled bacterium--a spirochete--called Borrelia burgdorferi (named for its discoverer, Dr. Willy Burgdorfer). The spirochete is carried to humans via tiny ticks that feed on animals, such as white-looted mice and white-tailed deer. It is not transmitted from human to human.

The misdiagnosis of Lyme disease, which many experts now believe to be a common occurrence, has adverse consequences. For example, long-term antibiotic therapy, the standard treatment for Lyme disease, is not only useless to people with fibromyalgia, but also subjects them needlessly to the risk of side effects like superinfection of the vagina, intestine, or mouth due to an overgrowth of bacteria.

In one study reported at the American College of Rheumatology meeting, only six of the 92 people seeking treatment for Lyme disease at the Rush Lyme Center in Chicago truly had the ailment. The other study involved 700 adults seen at a Lyme center in New Jersey; 77 of them actually had fibromyalgia.

There are several reasons why Lyme disease is so difficult to diagnose. For example, the tell-tale red circular rash develops around the tick bite in only 75% of cases. Many of the symptoms--fatigne, mild headache, pain and stiffness in muscles and joints, slight fever, swollen glands-are similar to those of fibromyalgia and several other ailments. Furthermore, the blood test for Lyme disease is highly inaccurate.

The Journal of the American Medical Association recently reported results of a testing program of 45 laboratories, which were randomly sent blood samples from people with and without Lyme disease. The investigators, Lori L. Bakken and colleagues at the Wisconsin State Laboratory of Hygiene, found a wide variation in lab performance. Between 4-21% failed to identify correctly the Lyme disease-infected samples. The false positive rate, that is, the erroneous finding of disease in healthy samples, was as high as 27%.

The Wisconsin investigators concluded: "Our results indicate that there is an urgent need for standardization of current testing methodologies. Until a national commitment is made, blood testing for Lyme disease will be of questionable value for the diagnosis of the disease."

The growing recognition of Lyme disease misdiagnoses has spotlighted fibromyalgia (formerly called fibrositis), a chronic ailment about which little is known. Some of its symptoms--muscle and joint pain, headaches, fatigue, sleep disturbances, numbness and/or a tingling feeling--are similar to those of arthritis. However, the standard arthritis treatments are ineffective for fibromyalgia because, unlike arthritis, it does not involve inflammation.

The lack of inflammation means that fibromyalgia does not cause the damage to joints and the risk of crippling associated with arthritis. Fibromyalgia pain comes not from the joints but from adjacent ligaments, tendons, and muscles. The diagnosis is usually made on the basis of symptoms because there is no lab test to identify the presence of fibromyalgia.

To make diagnostic matters even more complicated, a recent study conducted at the Tufts University School of Medicine in Boston found that some people have fibromyalgia triggered by Lyme disease. Of 287 people treated at a Lyme disease clinic during a three-year period, 22 had fibromyalgia associated with Lyme disease (Annals of Internal Medicine, 15 August 1992).

The investigators, Hal Dinerman, M.D., and Allen C. Steere, M.D., of Tufts University School of Medicine and the New England Medical Center, found that nine of the people developed widespread muscu1oskeletal pain, tender points, dysethesias (impaired sensation), memory difficulties, and debilitating fatigue. Their symptoms lasted an average of 1.7 months after early symptoms of Lyme disease. The investigators noted that the signs of Lyme disease resolved with antibiotic therapy, usually given intravenously for two to four weeks, but the symptoms of fibromyalgia persisted.

Doctors do not know what causes fibromyalgia or why childbearingage women make up the majority of those afflicted. Drs. Dinerman and Steere summed up prevailing theories, noting that it can be triggered by various infections, thyroid disease, head trauma, or emotional stress. Although it is an old syndrome that has merely received increased attention in recent years, fibromyalgia often goes unrecognized by physicians. They are likely to dismiss sufferers as hypochondriacs and refer them to a psychiatrist after all available tests show that nothing is wrong.