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Differential diagnosis between ME/CFS and Chronic Lyme Disease

Currently the differential diagnosis between ME/CFS and Chronic Lyme disease is both difficult and under dispute. One reason is because of conflicting opinions among Lyme Disease specialists as to the actual case definition of Lyme disease and its proper and accurate diagnosis. Some Lyme disease specialists deny that chronic Lyme Disease exists at all. So they claim that Lyme Disease, properly treated, does not have a chronic form (more than a few months duration.). In fact, there is no doubt that chronic Lyme disease is a very real illness. Some physicians who acknowledge this also often theorize that any possible chronic Lyme is really ME/CFS.

The major symptoms of chronic Lyme disease that overlap with ME/CFS are:

  • cognitive dysfunction and mood changes
  • central nervous system irritability, including parathesias (numbness, tingling crawling and itching sensations)
  • fatigue
  • flu-like illness: fevers, malaise, headache, muscle aches
  • joint aches (arthralgia) and intermittent swelling and pain of one or a few joints.
  • sleep disturbance

Differential diagnosis between ME/CFS and chronic Lyme is of critical importance. Chronic Lyme disease left untreated can become extremely serious, even life-threatening. The longer it is left untreated, the longer antibiotic treatment may take to work effectively. Therefore, misdiagnosis of chronic Lyme disease as ME/CFS can have severe consequences for patients.

What are some of the issues of differential diagnosis? First, Lyme disease must be diagnosed properly—and there is much dispute as to how such diagnosis is properly done. The Centers for Disease Control Testing Protocol, which most doctors will follow, is seriously deficient. The protocol first calls for an Elisa test, which if positive, is followed by the more accurate Western Blot test. However, the Elisa test may show up to 80% false negatives—meaning the person is actually positive for Lyme, but the test comes up negative. Therefore, anyone with chronic Lyme symptoms should have the Western Blot immediately. However there is much dispute and confusion among specialists about the proper interpretation of the Western Blot. The Western Blot is not an "all or nothing" test. There are numerous bands which must be looked at and interpreted. A non-specialist may read a Western blot as negative, when a knowledgeable specialist may see a likelihood of Lyme in the same test.

Other specialized laboratory tests, which may provide greater diagnostic information, can also be run by specialists. Further accurate diagnosis involves careful clinical evaluation and detailed history.

A patient suspected of having chronic Lyme disease and his/her family must educate themselves about how chronic Lyme is diagnosed and where to find a doctor who has the knowledge and motivation to make the most accurate diagnosis possible.

Complicating the matter is that some Lyme specialists will over diagnose chronic Lyme and will make a tentative diagnosis, after testing, primarily on symptoms and history. Some physicians will begin treatment as an adjunct to diagnosis, the notion being that if the treatment begins to work, then the Chronic Lyme is identified.

The serious issue here is that ME/CFS and Chronic Lyme may clinically appear almost identical. If an ME/CFS patient is misdiagnosed with Chronic Lyme and started on treatment, there can be severe consequences, both from the effects of treatment and the time and costs involved.