Management of Lyme disease.

The microbiology, transmission, epidemiology, pathogenesis, clinical manifestations, diagnosis, and treatment of Lyme disease are reviewed. Lyme disease, a tick-borne syndrome, was first described in 1975. The etiologic agent of Lyme disease is Borrelia burgdorferi, a slow-growing spirochete. Lyme disease is the most prevalent tick-borne disease in this country; endemic areas in the United States include the northeastern, north central, and western regions. Both infectious and immunologic mechanisms are important factors in the pathogenesis of Lyme disease. The primary mechanism, however, is thought to be infectious. Three stages of Lyme disease have been described; stage I, characterized by erythema chronicum migrans and flu-like symptoms; stage II, characterized by dermatologic, ophthalmologic, neurologic, and cardiac disorders; and stage III, characterized by arthritis, a multiple sclerosis-like syndrome, psychiatric disorders, and a chronic fatigue syndrome. Therapy with penicillin or tetracycline hastens the resolution of stage I symptoms. Treatment duration normally ranges between 10 days and three weeks. Tetracycline or doxycycline appears to be more effective than penicillin in preventing the development of late Lyme disease. Although intravenous penicillin G and ceftriaxone are both effective for the treatment of late Lyme disease, many clinicians consider ceftriaxone to be the agent of choice. Whether exposed patients from endemic areas should receive antimicrobial prophylaxis is controversial. Further clinical studies are needed to determine optimal therapy for the various stages of Lyme disease, particularly Lyme arthritis.