Lyme Essay, Research Paper

Lyme Disease

Lyme Arthritis

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

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

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 investigate and

identify the disorder. In 1981, Dr. Willy Burgdorfer identified the

bacterial spirochete organism (Borrelia Burgdorferi) which causes this

disorder.

Affected Population

Lyme Disease occurs in wooded areas with populations of mice and

deer which carry ticks, and can be contracted during any season of the

year.

Related Disorders

Rheumatoid Arthritis is a disorder similar in appearance to Lyme

disease. However, the pain in rheumatoid arthritis is usually more

pronounced. Morning stiffness and symmetric joint swelling more

commonly occur in rheumatoid arthritis, and knotty lumps under the skin

may be present over bony prominences. Bony decalcification which can

be prominent in Rheumatoid Arthritis is detected on X-rays.

Brachial Neuritis, also known as Parsonnage-Turner Syndrome, is a

common inflammation of a group of nerves that supply the arm, forearm,

and hand (brachial plexus). It is characterized by severe neck pain in

the area above the collarbone (supraclavicular) that may radiate down

the arm and into the hand. There also may be weakness and numbness

(hyperesthesia) of the fingers and hands. Although many cases have no

apparent cause, this syndrome may occur following an immunization

(tetanus or diptheria), surgery, or infection with Lyme Disease.

Therapies: Standard

For adults with Lyme disease the antibiotic tetracycline is the

drug of choice. Penicillin V and erythromycin have also been used. In

children penicillin V is recommended rather than tetracycline.

Penicillin V is now recommended for neurological abnormalities. It is

not yet clear whether antibiotic treatment is helpful later in the

illness when arthritis is the most predominant symptom. Treatment

should be started as soon as the rash appears, even before the Enzyme

Linked Immunoabsorbent Assay (ELISA) test is completed. Results of

this test may be inaccurate if patients have had antibiotics soon after

contracting Lyme Disease, or in those who have weakened immune systems.

If lyme Disease is contracted during pregnancy, careful monitoring

by physicians is highly recommended to avoid possible fetal

abnormalities and/or complications.

For tense knee joints due to increased fluid flowing in the joint

spaces (effusions), the use of crutches is often helpful. Aspiration

of fluid and injection of a corticosteroid may be beneficial. If the

patient with Lyme disease has marked functional limitation, excision of

the membrane lining the joint (synovectomy) may be performed for

chronic (6 months or more despite therapy) knee effusions, but

spontaneous remission can occur after more than a year of continuous

knee involvement.

When Lyme Disease is contracted during pregnancy, treatment with

penicillin should begin immediately to avoid the possibility of fetal

abnormalities.

In 1989 a new Lyme Disease antibody test, manufactured by

Cambridge Biosciences Corp., was approved by the FDA. This test is

being used by local laboratories throughout the nation, making tests

more available to the general population. However, it is 97% specific

for antibodies to Lyme disease when compared to Western blot tests, but

it cannot identify the live bacteria in patients who have not yet

developed the antibodies.

Therapies: Investigational

Researchers are trying to develop a test that will identify the

Lyme disease bacteria in patients who have not yet developed the

antibodies. This would enable doctors to diagnose Lyme disease very

early in the course of the illness.

This disease entry is based upon medical information available

through July 1989. Since NORD’s resources are limited, it is not

possible to keep every entry in the Rare Disease Database completely

current and accurate. Please check with the agencies listed in the

Resources section for the most current information about this disorder.

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