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Lyme Disease

Lyme disease is an illness recently described in the United States and is named after Lyme, Connecticut, where it was first studied in 1975. The disease has subsequently been recognized in at least 14 additional states. Cases have been reported primarily from three geographic areas: the East (Connecticut, Delaware, Georgia, Maryland, Massachusetts, New Jersey, New York, Pennsylvania, Rhode Island), the Midwest (Minnesota, Wisconsin), and the West (California, Nevada, Oregon); a case has also been reported in Arkansas. As awareness of the disease increases, it is likely that additional states will be added to this list.

Lyme disease is a systemic illness characterized by a distinctive primary skin lesion (erythema chronicum migrans (ECM)) and, in many cases, subsequent development of significant cardiac, neurologic, and/or arthritic complications. Nonspecific systemic symptoms such as fever, chills, malaise, arthralgia and headache are also usually present.

ECM, the most characteristic feature of the disease, begins as a red macule or papule that expands in a circular manner over a number of days. As the lesion expands, central clearing often occurs. Lesions can reach diameters of 12 inches or more, and many people will have multiple skin lesions, generally beginning several days after an initial lesion. With time, the skin lesions fade, lasting a median of 3 weeks.

Days to weeks after the skin lesion appears, cardiac, neurologic, or joint manifestations may develop. Not all persons with ECM, however, will develop these complications. The usual cardiac manifestations are atrioventricular conduction defects, although electrocardiographic changes consistent with myocarditis or pericarditis may occur. The most common neurologic manifestations are headache and stiff neck, consistent with meningoencephalitis. Cranial nerve palsies, as well as motor and sensory radiculitis, may also be seen. Both cardiac and neurologic abnormalities tend to be self-limited, although repeated episodes may occur.

The arthritic manifestations, which begin weeks to as long as two years (median, four weeks) after the appearance of ECM, are characterized by intermittent attacks of acute arthritis, usually of the large joints, with each episode lasting days to several months. About 10% of people with Lyme disease, primarily those with preceding attacks of acute arthritis, subsequently develop chronic arthritis, usually in the knee.

Lyme disease is thought to be caused by an infectious agent transmitted by Ixodes ticks, although other vectors could be involved. In Connecticut, about 20% of patients remember a tick bite 3-30 days before the appearance of ECM at the site; in those cases in which the tick was examined, it was identified as I. dammini. In California and Oregon, I. pacificus ticks have been implicated. As further evidence for an infectious etiology, antimicrobial therapy has been shown to significantly alter the course of the disease. Penicillin V or tetracycline, 250 mg, orally, four times a day for 10 days, can successfully treat the early phases of the disease when ECM is present and can prevent, or at least ameliorate, the subsequent, more severe cardiac, neurologic, or arthritic phases.

Work is underway to identify an agent of the disease and to develop a diagnostic laboratory test. Recently, a spirochete was isolated from I. dammini ticks; indirect fluorescent antibody testing of patient sera suggests that this may be the etiologic agent of Lyme disease. At present, however, the diagnosis of Lyme disease rests on clinical grounds, based principally on recognition of typical ECM skin lesions in association with cardiac, neurologic, and arthritic abnormalities.

The majority of Lyme disease patients become ill in the summer months. Because the full geographical distribution and the number of cases are not known, State and Territorial Epidemiologists and CDC are attempting to identify all cases of Lyme disease that occur in the United States this year. Health care providers are encouraged to report cases to appropriate local and state health departments. Reported by AC Steere, MD, Yale University School of Medicine, New Haven, Connecticut; Special Pathogens Br, Bacterial Diseases Div, Center for Infectious Diseases, CDC.


  1. Steere AC, Malawista SE, Hardin JA, Ruddy S, Askenase PW, Andiman WA. Erythema chronicum migrans and Lyme arthritis. The enlarging clinical spectrum. Ann Intern Med 1977;86:685-98.

  2. Steere AC, Malawista SE, Newman JH, Spieler PN, Bartenhagen NH. Antibiotic therapy in Lyme disease. Ann Intern Med 1980;93:1-8.

  3. CDC. Lyme disease--United States, 1980. MMWR 1981;30:489-92,497.

  4. Burgdorfer W, Barbour AG, Hayes SF, Benach JL, Grunwaldt E, Davis JP. Lyme disease--a tick-borne spirochetosis? Science 1982;216:1317-19.

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