Diagnosis of lyme disease
In endemic areas, Lyme disease is diagnosed by recognition of erythema migrans. IgG antibodies to B. burgdorferi are usually detectable 4 to 6 weeks after the initial infection. If an enzyme-linked immunosorbent assay (ELISA) or immunofluorescent assay (IFA) is positive or equivocal, the specimen should also be tested with a standardized Western blot