Lyme Disease


The National Organization for Rare Disorders (NORD), P.O. Box 8923, New
Fairfield, CT 06812, (203) 746-6518

Lyme Disease
Lyme Arthritis

General Discussion
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The information contained in the Rare Disease Database is provided for
educational purposes only. It should not be used for diagnostic or
treatment purposes. If you wish to obtain more information about this
disorder, please contact your personal physician and/or the agencies listed
in the "Resources" section of this report.

Lyme disease is a tick-transmitted inflammatory disorder characterized
by an early focal skin lesion, and subsequently a growing red area on the
skin (erythema chronicum migrans or ECM). The disorder may be followed
weeks later by neurological, heart or joint abnormalities.


Symptomatology
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The first symptom of Lyme disease is a skin lesion. Known as erythema
chronicum migrans, or ECM, this usually begins as a red discoloration
(macule) or as an elevated round spot (papule). The skin lesion usually
appears on an extremity or on the trunk, especially the thigh, buttock or
the under arm. This spot expands, often with central clearing, to a
diameter as large as 50 cm (c. 12 in.). Approximately 25% of patients with
Lyme disease report having been bitten at that site by a tiny tick 3 to 32
days before onset of ECM. The lesion may be warm to touch. Soon after
onset nearly half the patients develop multiple smaller lesions without
hardened centers. ECM generally lasts for a few weeks. Other types of
lesions may subsequently appear during resolution. Former skin lesions may
reappear faintly, sometimes before recurrent attacks of arthritis. Lesions
of the mucous membranes do not occur in Lyme disease.

The most common symptoms accompanying ECM, or preceding it by a few
days, may include malaise, fatigue, chills, fever, headache and stiff
neck. Less commonly, backache, muscle aches (myalgias), nausea, vomiting,
sore throat, swollen lymph glands, and an enlarged spleen may also be
present.

Most symptoms are characteristically intermittent and changing, but
malaise and fatigue may linger for weeks.

Arthritis is present in about half of the patients with ECM, occurring
within weeks to months following onset and lasting as long as 2 years.
Early in the illness, migratory inflammation of many joints
(polyarthritis) without joint swelling may occur. Later, longer attacks
of swelling and pain in several large joints, especially the knees,
typically recur for several years. The knees commonly are much more
swollen than painful; they are often hot, but rarely red. Baker\'s cysts
(a cyst in the knee) may form and rupture.

Those symptoms accompanying ECM, especially malaise, fatigue and low-
grade fever, may also precede or accompany recurrent attacks of arthritis.
About 10% of patients develop chronic knee involvement (i.e. unremittent
for 6 months or longer).

Neurological abnormalities may develop in about 15% of patients with
Lyme disease within weeks to months following onset of ECM, often before
arthritis occurs. These abnormalities commonly last for months, and
usually resolve completely. They include:

1. lymphocytic meningitis or meningoencephalitis
2. jerky involuntary movements (chorea)
3. failure of muscle coordination due to dysfunction of the cerebellum
(cerebellar ataxia)
4. cranial neuritis including Bell\'s palsy (a form of facial paralysis)
5. motor and sensory radiculo-neuritis (symmetric weakness, pain,
strange sensations in the extremities, usually occurring first in
the legs)
6. injury to single nerves causing diminished nerve response
(mononeuritis multiplex)
7. inflammation of the spinal cord (myelitis).

Abnormalities in the heart muscle (myocardium) occur in approximately
8% of patients with Lyme disease within weeks of ECM. They may include
fluctuating degrees of atrioventricular block and, less commonly,
inflammation of the heart sack and heart muscle (myopericarditis) with
reduced blood volume ejected from the left ventricle and an enlarged heart
(cardiomegaly).

When Lyme Disease is contracted during pregnancy, the fetus may or may
not be adversely affected, or may contract congenital Lyme Disease. In a
study of nineteen pregnant women with Lyme Disease, fourteen had normal
pregnancies and normal babies.

If Lyme Disease is contracted during pregnancy, possible fetal
abnormalities and premature birth can occur.


Etiology
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Lyme disease is caused by a spirochete bacterium (Borrelia Burgdorferi)
transmitted by a small tick called Ixodes dammini. The spirochete is
probably injected into the victim\'s skin or bloodstream at the time of the
insect bite. After an incubation period of 3 to 32 days, the organism
migrates outward in the skin, is spread through the lymphatic system or is
disseminated by the blood to different body organs or other skin sites.

Lyme Disease was first described in 1909 in European medical journals.
The first outbreak in the United States occurred in the early 1970\'s in Old
lyme, Connecticut. An unusually high incidence of juvenile arthritis in the
area led scientists to