How is Lyme disease diagnosed?
Doctors use a variety of methods to diagnose Lyme disease. Different approaches may be used depending on the stage of the disease. Early Lyme disease is easily diagnosed if a person has the characteristic red, bull's-eye rash. The diagnosis is considered when a person has recently been in an area known to have ticks that harbor the bacteria. Sometimes the diagnosis is not as clear-cut. The doctor may perform a physical exam and order tests to exclude other potential problems with the heart, joints, and nervous system.
Antibody tests are available for Lyme disease, but they are not useful in the early stage. They are more helpful in the diagnosis of later stages. A test called the ELISA assay is used to detect Lyme disease antibodies. However, there's a possibility of a false positive diagnosis because Lyme disease antibodies may be present in the body for years after the illness has resolved. The most reliable test available to confirm the diagnosis of Lyme disease is called the Western Blot assay.