investigation

Laboratory findings in Lyme Disease

The diagnosis of Lymedisease is made on clinical findings, epidemiologic features, and an elevated antibody response to B burgdorferi. The available laboratory tests (with the exception of a positive culture from an EM lesion) can be unreliable. Serologic testing only should be undertaken when clinical and epidemiologic features suggest Lymediseaseas the diagnosis.

Most patients with B burgdorferi are found to have detectable antibodies when tested with enzyme-linked immunosorbent assay (60-70% within 2-4 weeks of infection and 90% by the disseminated and persistent stages). However, serologic tests lack standardization, their accuracy is often unsubstantiated, and false-positive results are common. IgM antibody appears 2-4 weeks after the EM lesion, peaks at 6-8 weeks, and declines after 4-6 months. IgG antibody appears 6-8 weeks after the EM lesion, peaks at 4-6 months, and remains at low levels despite antibiotic therapy. A fourfold rise in antibody titer would be suggestive of recent infection. Western blot analysis is used to confirm results obtained by enzyme-linked immunosorbent assay.

Diagnosis and test in Lyme Disease

Lyme disease may be hard to diagnose because its symptoms are like those of many other illnesses. Your doctor will take a careful medical history and do a physical examination to help diagnose early Lyme disease. You may be asked whether you have recently visited an area where you may have been exposed to ticks. The doctor will ask about your symptoms and look for physical signs that may indicate Lyme disease. The clearest physical sign is an expanding, circular red rash (called erythema migrans). See a picture of a Lyme disease rash.

The often vague, flu-like symptoms of Lyme disease can easily be misdiagnosed as another illness(such as chronic fatigue syndrome).