[Dilemma: to test or not to test for Lyme borreliosis in general practice].

There is no such thing as a perfect diagnostic test and the value of a test depends on the situation in which the test is being used. Here, we discuss two options for dealing with the diagnostic process for Lyme borreliosis in general practice. One option is to manage, treat or refer according to clinical signs and symptoms, in accordance with Dutch practice guidelines. The other option is to use laboratory tests to guide further patient management (treatment or referral). The choice depends on currently unknown factors, such as the pre-test probability of Lyme disease in patients presenting to general practitioners. Furthermore, clarity is required about how to proceed after a positive or negative test result. The consequences of a false test result will depend on the patient's status, possible alternative diagnoses and treatment options. Both physician and patient should be aware of the shortcomings of diagnostic tests.