Lyme disease is a disease caused by the bacteria Borrelia burgdorferi. People get Lyme disease after being bitten by a tick that is infested with the bacteria.
If caught and removed or treated early, there is little, if any clinical consequence to a B. burgdorferi tick bite. If not found until the later stages of infection, people with Lyme disease are more likely to have symptoms.
The ticks that carry B. burgdorferi are found in forested areas of Asia, north-western, central and eastern Europe, and the United States. In the U.S., the blacklegged ticks (deer ticks) are usually found in the Northeast, Mid-Atlantic, Upper Midwest, and Pacific coast.
People who spend a lot of time outdoors in rural or wooded, grassy suburban areas are at higher risk of getting Lyme disease. Most infections occur in the late spring and early summer but people can get bitten all year round if temperatures are unusually high.
Early symptoms of Lyme disease can start days or weeks after a tick bite. The symptoms can include:
A rash at the site of the bite. The rash appears within a month of getting bitten. The center of the red rash may be skin-colored. It might get bigger over a few days and parts of it may fade over time.
Body aches and pains
Muscle and joint aches
Swollen lymph nodes
If the infection is not treated, it can spread to the joints, heart, and nervous system. These “late” symptoms may include:
Rashes in other parts of the body
Arthritis with severe joint pain and swelling in large joints such as the knees
Pain that comes and goes in the tendons, muscles, joints, and bones
Irregular heart beat
Mental fog (confusion, inability to concentrate, short term memory loss)
Severe headache and neck stiffness
Numbness or tingling in the hands or feet
The diagnosis is based on the likelihood of exposure to an infected deer tick, symptoms, ruling out other illnesses with similar symptoms, and physical exam. The diagnosis can be confirmed with lab tests.
The lab tests check for antibodies made by the body in response to B. burgdorferi. These antibodies can take several weeks to develop so it may be falsely negative if the blood is sampled shortly after an infected deer tick bite. It can also be falsely positive if it detects antibodies against other proteins, so a second test using the same sample is required to confirm any positive result.
Lyme disease is treated with either oral or intravenous (IV) antibiotics. The treatment varies according to the stage of disease and the type of symptoms. In general, most cases of early stage Lyme disease need just two or three weeks of oral antibiotics (usually doxycycline, amoxicillin, or cefuroxime). Patients with arthritis may need a longer course of oral or even IV antibiotics. Infections involving the nervous system or heart may also require IV antibiotics.
In some patients, symptoms such as muscle aches and fatigue persist even after treatment completion. The cause of this post-Lyme disease syndrome is not known. Treatment with more antibiotics has not proven to be of benefit but most people with the syndrome will improve over time.
Anyone can get a tick bite and it is possible to get Lyme disease more than once. To reduce the risk of Lyme disease:
Avoid tick-habitats. Avoid wooded, tall grass, leaf-covered ground and brush. Stay on open paths.
Cover up. Wear closed shoes and long pants tucked into socks.
Use repellants and insecticide. Spray your skin and clothes with repellents containing DEET when outdoors.
Check for ticks. After spending time outdoors, check yourself, your children, and pets for ticks.
Remove ticks within 24 to 36 hours. Remove the tick by gently and steadily pulling its head with tweezers. If you do not know how long it has been there or if it has been attached for more than two days, consult your doctor.