Lyme disease is a bacterial infection. It is passed from an infected deer tick that has attached and fed for more than 36 hours.
Lyme disease is caused by bacteria found in some deer ticks. The bacteria passes from the tick when it bites and feeds for a long time.
The bacteria can pass into the blood if the infection is not treated. This allows the bacteria to travel through the body and affect different areas.
Factors that may increase your chances of Lyme disease:
- Living in the northeastern, northwestern, mid-Atlantic, or upper north-central regions of the US, and northwestern California
- Outdoor activities such as hiking, camping, and gardening in areas/seasons with deer ticks
- Living near or going to wooded, grassy areas
- Working outdoors such as surveying, landscaping, forestry, gardening, and utility company service work
The symptoms of Lyme disease will be different in each person. Some people will not have symptoms. Those that do may have mild or severe symptoms.
The first sign may be a red rash. The rash starts as a small red spot at the site of the tick bite. It will then spread over the next few days or weeks to form a circular or oval-shaped rash. Sometimes, the rash resembles a bull's eye with a red ring around a clear area with a red center. The rash may cover a small dime-sized area or a wide area of the body.
This is an example of a Lyme disease rash shaped like a bull's eye. It may not always be this shape, nor will a rash always appear.
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In the first 3-30 days after the bite, if the infection has not spread you may notice:
- Muscle and joint aches
- Swollen glands
These symptoms do not necessarily mean you have Lyme disease, even if you have spent time outdoors. See your doctor right away if you have these symptoms and think you have been exposed to a tick.
Early Disseminated Infection
An infection that has begun to spread may cause the following symptoms in days to weeks after the bite:
- Multiple lesions
- Persistent headache, stiff neck
- Diffuse numbness, tingling, burning
- Intermittent joint pain and swelling
- Impaired motor coordination
- Irregular heart rhythm
- Muscle pain and swelling
- Facial paralysis— Bell palsy
Symptoms can develop months or years after the tick bite in untreated infections. These symptoms may occur regularly or intermittently and include:
- Painful inflammation of the joints—arthritis
- Trouble with concentration or memory
- Shooting pains, numbness, and tingling
Less common symptoms of late Lyme disease include:
- Heart abnormalities
- Eye problems such as conjunctivitis
- Chronic skin disorders
- Limb weakness
- Persistent motor coordination problems
The doctor may suspect Lyme disease based on the classic bulls-eye rash and knowledge of a tick bite. It will also help to know if you have been in an area with known Lyme disease.
The body may make antibodies against the infection about 2 to 4 weeks after the infection. A blood test may help look for these antibodies. The results of the blood test will be used along with symptoms and overall risk to make a diagnosis.
Lyme disease responds well to antibiotics. These medications can kill the bacteria.
Treatment may be given at home or in the hospital based on your illness. Antibiotics may be given by mouth or through an IV. Treatment may last from 5 to 28 days.
Some may have longer lasting issues after treatment such as chronic arthritis. A treatment plan will be made to help manage it. This may include a referral to a Rheumatologist. They focus on conditions that cause pain and swelling of joints, muscles, and bones.
To help reduce the chances of Lyme disease:
- Avoid areas that are likely to be infested with deer ticks such as moist, shaded, wooded, or grassy areas
When going to wooded, grassy areas, especially in spring and summer:
- Wear light-colored clothing with a tight weave to spot ticks easily.
- Wear enclosed shoes.
- Wear a long sleeve shirt. Tuck it into your pants.
- Tuck pants into socks or boot tops.
- Wear a hat.
- Stay on cleared, well-traveled paths and walk in the center of trails to avoid overgrown grass and brush. Avoid sitting on the ground or stone walls.
- Remove leaf litter, brush, and woodpiles from around the home and the edges of the yard.
Insect repellent can help prevent tick bites. Repellents containing DEET can be applied to clothes and exposed skin. Repellents that have permethrin can be applied to pants, socks, and shoes, but not to skin. Repellents can cause eye irritation and skin reactions. Be sure to read the label for instructions on application, including:
- Do not apply near eyes, nose, or mouth.
- Do not apply to children's hands.
- Wash your skin when you return indoors.
Deer ticks are unlikely to pass the infection unless they are in contact with the skin for at least 36 hours. After spending time outdoors in a high risk area:
- Do a full-body check for ticks at the end of a day spent outdoors. Consider bathing or showering within 2 hours of coming indoors.
- Check your child for ticks. Make sure to check for hidden areas like the hair, around the ears, or behind the knees.
- Check pets and gear for ticks.
- Put clothes worn outdoors in the dryer for 20 minutes. This will kill any unseen ticks.
If you do find a tick, remove it by doing the following:
- Use a pair of tweezers. Grasp the tick as close to the skin as possible and pull upward.
- Wipe the site with an antiseptic to prevent infection.
There are some steps that do not help. They may cause more problems.
- Do not put a hot match to the tick.
- Do not cover the tick with petroleum jelly, nail polish, or any other substances.
If you have been bitten by a deer tick, watch for a rash to appear. This is especially important if Lyme disease is common in your area. A rash can occur in about 70 to 80% of infected persons. It often begins at the tick bite site.
Your doctor may recommend a single dose of an antibiotic if you had a tick bite in a high-risk area. This may reduce the risk of Lyme disease if taken within 72 hours after a tick bite.
Centers for Disease Control and Prevention
Lyme Disease Association of Canada
Lyme disease. Centers for Disease Control and Prevention website. Available at: https://www.cdc.gov/lyme. Accessed January 29, 2021.
Lyme disease. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T114365/Lyme-disease. Accessed January 29, 2021.
Lyme disease. Family Doctor—American Academy of Physicians website. Available at: https://familydoctor.org/condition/lyme-disease. Accessed January 29, 2021.
Lyme disease. National Institute of Allergy and Infectious Diseases website. Available at: https://www.niaid.nih.gov/diseases-conditions/lyme-disease. Updated April 6, 2016. Accessed February 15, 2018.
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Last reviewed February 2021 by EBSCO Medical Review Board David L. Horn, MD, FACP Last Updated: 1/29/2021