How is Lyme disease diagnosed?
Lyme disease may be difficult to diagnose because many of its symptoms mimic those of other disorders. In addition, the only distinctive symptom of Lyme disease, the red rash, does not happen or is not noticed by one-fifth of those who become infected. Many people can’t recall having been bitten by a tick, because the tick is tiny, and its bite is usually painless.
If no rash is present, doctors will make the diagnosis on the basis of a detailed medical history, a careful physical examination, and laboratory tests to confirm their suspicion.
No test is perfect and the current testing for Lyme disease is no exception. Very early in the disease, testing will be negative as the body has not had time to develop a response that can be measured. Once the body responds, the positive test may persist for years even if Lyme is treated properly. Current research efforts are working to develop improved testing for Lyme disease.