On the controversy:
The CDC clinical criteria for Lyme Disease which exist for the purpose of monitoring the rate of Lyme disease nationally are quite narrowly defined in order to ensure a high degree of specificity in the diagnosis. These criteria are mainly useful for the early stages and rheumatological presentations of Lyme Disease, such as when a patient appears with an erythema migrans rash, arthritis, a Bell's palsy, or early central neurologic Lyme disease (meningitis or encephalitis)
Other physicians who use a broader more inclusive set of clinical criteria for the diagnosis of Lyme disease will make the diagnosis of Lyme Disease and initiate treatment. The latter group of doctors, by treating some patients for "probable Lyme Disease", will make use of antibiotic responsiveness to confirm their diagnostic impression. These physicians, by erring on the side of not letting a patient with probable Lyme Disease go untreated, will help many patients who otherwise would not get treatment; undoubtedly, however, because of the inclusiveness of their diagnostic approach, these physicians will also treat some patients with antibiotics who do not have Lyme Disease. These physicians would argue that the serious consequences for physical, cognitive, and functional disability associated with chronic Lyme Disease outweigh the risks of antibiotic therapy.
Both sets of doctors are practicing medicine in a reasonable fashion based on the application of certain diagnostic principles, although the therapeutic approaches differ considerably stemming from the narrow vs broad criteria for diagnosis. This is the essence of the medical controversy surrounding chronic Lyme disease. Until medical doctors have a test that definitively identifies the presence or absence of infection (and such a test does not yet exist), the controversy about the diagnosis and treatment of chronic Lyme Disease will continue.