A Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial of the Safety and Efficacy of Ceftriaxone and Doxycycline in the Treatment of Patients With Seronegative Chronic Lyme Disease

Inclusion Criteria: You may be eligible for this study if you: * Are at least 18 years of age. * Are seronegative for antibodies against B. burgdorferi antigens by Western Blot at enrollment. * Have documented history of acute Lyme disease. * Have had a rash (erythema migrans) that resembles a bullseye. This skin aberration usually occurs after a tick bite in late spring, summer, or early fall and is sometimes accompanied by fatigue, fever, headache, mild stiff neck, arthralgia or myalgia. * Have had one or more clinical features typical of Lyme disease acquired in the United States (see technical summary) * Have had one or more of the following symptoms and conditions that have persisted for at least 6 months (but less than 12 years) and are not attributable to another cause or condition: a) widespread musculoskeletal pain and fatigue that began coincident with or within 6 months following initial infection with B. burgdorferi. b) certain neurologic symptoms including memory impairment and nerve pain, beginning within 6 months following initial infection with B. burgdorferi. * Have had a physician-documented history of prior antibiotic treatment with a currently recommended antibiotic regimen. Exclusion Criteria: You will not be eligible for this study if you: * Have previously enrolled in this study. * Are pregnant, lactating, or unable to use birth control measures during the treatment period of this study. * Are taking chronic medication that could interfere with evaluation of symptoms. * Are taking or have taken various medications that could interfere with the evaluation of symptoms (see technical summary). * Are hypersensitive to ceftriaxone or doxycycline. * Have active inflammatory synovitis. * Have another disease that could account for symptoms of acute Lyme disease. * Have another serious or active infection. * Are unable to tolerate an IV. * Have tested positive for Borrelia DNA in plasma or cerebrospinal fluid at the time of initial evaluation for study. * Have tested seropositive by Western Blot (these patients may be offered enrollment in seropositive study).