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Symptoms
Clinical Description: Lyme disease most often presents
with a characteristic "bull's-eye" rash, erythema migrans,
accompanied by nonspecific symptoms such as fever, malaise, fatigue,
headache, muscle aches (myalgia), and joint aches (arthralgia).
The incubation period from infection to onset of erythema migrans is
typically 7 to 14 days but may be as short as 3 days and as long as
30 days.
Some infected individuals have no recognized illness (asymptomatic
infection determined by serological testing), or manifest only
non-specific symptoms such as fever, headache, fatigue, and myalgia.
Lyme disease spirochetes disseminate from the site of the tick bite
by cutaneous, lymphatic and blood borne routes. The signs of early
disseminated infection usually occur days to weeks after the
appearance of a solitary erythema migrans lesion. In addition to
multiple (secondary) erythema migrans lesions, early disseminated
infection may be manifest as disease of the nervous system, the
musculoskeletal system, or the heart. Early neurologic
manifestations include lymphocytic meningitis, cranial neuropathy
(especially facial nerve palsy), and radiculoneuritis.
Musculoskeletal manifestations may include migratory joint and
muscle pains with or without objective signs of joint swelling.
Cardiac manifestations are rare but may include myocarditis and
transient atrioventricular blocks of varying degree.
B. burgdorferi infection in the untreated or
inadequately treated patient may progress to late disseminated
disease weeks to months after infection. The most common objective
manifestation of late disseminated Lyme disease is intermittent
swelling and pain of one or a few joints, usually large,
weight-bearing joints such as the knee. Some patients develop
chronic axonal polyneuropathy, or encephalopathy, the latter usually
manifested by cognitive disorders, sleep disturbance, fatigue, and
personality changes. Infrequently, Lyme disease morbidity may be
severe, chronic, and disabling. An ill-defined post-Lyme disease
syndrome occurs in some persons following treatment for Lyme
disease. Lyme disease is rarely, if ever, fatal.
Diagnosis: The diagnosis of Lyme disease is based
primarily on clinical findings, and it is often appropriate to treat
patients with early disease solely on the basis of objective signs
and a known exposure. Serologic testing may, however, provide
valuable supportive diagnostic information in patients with endemic
exposure and objective clinical findings that suggest later stage
disseminated Lyme disease. When serologic testing is indicated, CDC
recommends testing initially with a sensitive first test, either an
enzyme-linked immunosorbent assay (ELISA) or an indirect fluorescent
antibody (IFA) test, followed by testing with the more specific
Western immunoblot (WB) test to corroborate equivocal or positive
results obtained with the first test. Although antibiotic treatment
in early localized disease may blunt or abrogate the antibody
response, patients with early disseminated or late-stage disease
usually have strong serological reactivity and demonstrate expanded
WB immunoglobulin G (IgG) banding patterns to diagnostic
B. burgdorferi antigens. Antibodies often persist for months
or years following successfully treated or untreated infection.
Thus, seroreactivity alone cannot be used as a marker of active
disease. Neither positive serologic test results nor a history of
previous Lyme disease assures that an individual has protective
immunity. Repeated infection with
B. burgdorferi has been documented.
B. burgdorferi can be cultured from 80% or more of biopsy
specimens taken from early erythema migrans lesions. However, the
diagnostic usefulness of this procedure is limited because of the
need for a special bacteriologic medium (modified Barbour-Stoenner-Kelly
medium) and protracted observation of cultures. Polymerase chain
reaction (PCR) has been used to amplify genomic DNA of
B. burgdorferi in skin, blood, cerobro-spinal fluid, and
synovial fluid, but PCR has not been standardized for routine
diagnosis of Lyme disease.
Additional Lyme
Disease Information
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