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Medical Encyclopedia: Lyme disease
URL of this page: http://www.nlm.nih.gov/medlineplus/ency/article/001319.htm
Alternative names
Borreliosis
Definition
Lyme disease is an inflammatory disease characterized by a skin rash, joint inflammation, and flu-like
symptoms, caused by the bacterium Borrelia burgdorferi transmitted by the bite of a deer tick. See also tick
removal.
Causes, incidence, and risk factors
Lyme disease was first described in the United States in the town of Old Lyme, Connecticut in 1975, but has
now been reported in most parts of the United States.
Most cases occur in the Northeast, upper Midwest, and along the Pacific coast. Mice and deer are the most
commonly infected animals that serve as host to the tick. Most infections occur in the late spring, summer,
and early fall.
The disease can sometimes be difficult to diagnose because the symptoms may mimic other diseases. A
characteristic red rash usually occurs at the site of the bite. However, the bite may go unnoticed. A few
months to years after the bite, joint inflammation, neurological symptoms, and sometimes heart symptoms
may occur.
The initial infection is called primary Lyme disease. From there, secondary Lyme disease and tertiary Lyme
disease may develop.
There are more than 16,000 cases of Lyme disease per year in the United States.
Risk factors for Lyme disease include walking in high grasses, other activities that increase tick exposure, and
having a pet that may carry ticks home.
Symptoms
Deer ticks can be so small that they are almost impossible to see. Therefore, many people with Lyme disease
never even saw a tick. These people are more likely to develop symptoms because the tick remained on their
body longer.
The symptoms of Lyme disease include:
A flat or slightly raised red lesion at the site of the tick bite (can be larger than 1 to 3 inches in
diameter, often with a clear area in the center)
Fever
Headache
Lethargy
Muscle pains
Stiff neck
Joint inflammation in the knees and other large joints
Additional symptoms that may be associated with this disease:
Itching, overall
unusual or strange behavior
Signs and tests
Physical examination in advanced Lyme disease may show evidence of joint, heart, or brain
abnormalities
Antibodies to Borrelia burgdorferi by immunofluorescence (IFA) or ELISA. ELISA tests are confirmed with a
Western blot test.
Treatment
Antibiotics are prescribed based on disease stages and manifestations. Doxycycline, tetracycline, cefuroxime,
ceftriaxone, and penicillin are some of the choices.
Anti-inflammatory medications, such as ibuprofen, are sometimes prescribed to relieve joint stiffness.
Note: Doxycycline is usually not prescribed for children until after all the permanent teeth have erupted. It
can permanently discolor teeth that are still forming.
Expectations (prognosis)
If diagnosed in the early stages, the disease can be cured with antibiotics. If left untreated, complications
involving joints, the heart, and the nervous system can occur.
Complications
Secondary Lyme disease
Tertiary Lyme disease
Calling your health care provider
Call your health care provider if symptoms of Lyme disease develop.
Prevention
When walking or hiking in wooded or grassy areas, tuck long pants into socks to protect the legs, and wear
shoes and long-sleeved shirts. Ticks will show up on white or light colors better than dark colors, making
them easier to remove from your clothing. Spray your clothes with insect repellant.
Check yourself and your pets frequently. If you find ticks, remove them immediately by using tweezers,
pulling carefully and steadily.
Ticks can be fairly large -- about the size of a pencil eraser -- or so small that they are almost impossible to
see. After returning home, remove your clothes and thoroughly inspect all skin surface areas, including your
scalp. Ticks can quickly climb up the length of your body. Some ticks are large and easy to locate. Other ticks
can be quite small, so carefully evaluate all spots on the skin.
Update Date: 6/15/2005
Updated by: Monica Gandhi, MD, MPH, Assistant Professor, Division of Infectious Diseases, UCSF, San Francisco, CA. Review
provided by VeriMed Healthcare Network.
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