Patient education: Lyme disease (The Basics)

What is Lyme disease? — 

This is an illness that can make you feel like you have the flu. It can also cause a rash or fever, as well as nerve, joint, or heart problems.

People can get Lyme disease after being bitten by a tiny insect called a tick. When a certain type of tick bites you, it can pass the germ that causes Lyme disease from its body to yours. But a tick can only infect you if it stays attached for at least a day and a half.

The ticks that carry Lyme disease feed on deer and mice. They are only about the size of a poppy seed when they are young, which is when they most often spread Lyme disease. They grow to about the size of a sesame seed as adults (figure 1).

Ticks are found in tall grass and on shrubs, and can attach to animals and people walking by. Ticks cannot fly or jump.

What are the symptoms of Lyme disease? — 

Symptoms can start days or weeks after a tick bite.

Lyme disease has 3 stages:

●In the first month, most people get a rash that can look like a "bull's eye" (picture 1). The rash might get bigger over a few days. In people with light skin, the rash is red, but its center can appear lighter. The rash can be harder to see in people with darker skin. In the month after the tick bite, some people also have symptoms like fever, headache, body aches, or feeling very tired.

●If Lyme disease is not treated, it can lead to other symptoms in the weeks to months after the tick bite. These can include problems such as paralysis of half of the face or meningitis (infection of the lining covering the brain). Lyme disease can also cause problems with the heart or skin.

●Months to years after the tick bite, people can develop other symptoms. This is sometimes called "late" Lyme disease. The most common symptom is pain and swelling of the joints, usually 1 or both knees. Some people can have other symptoms, such as numbness, tingling, or pain in the legs. They can also have skin problems, such as skin swelling or thinning, but this happens mostly in Europe.

Some people do not notice a rash or remember being bitten by a tick. They might not learn they have Lyme disease until they develop later symptoms.

Is there a test for Lyme disease? — 

Yes. Blood tests can show if you are infected with the germ that causes Lyme disease. But it takes time for the blood tests to turn positive. This means the tests do not work if you get them right after being bitten or when you have the early rash. Because of this, if you have a recent tick bite or the rash, you do not need a blood test for Lyme disease. If you have been ill from Lyme disease for more than a month, the tests work well.

If your doctor or nurse suspects you have Lyme disease, they will do an exam and ask you questions. They will use this information (and your blood test result, if needed) to decide your treatment.

How is Lyme disease treated? — 

Lyme disease is usually treated with antibiotics. There are a few different types. Antibiotics help even if Lyme disease is found in a later stage.

Treatment with antibiotics should help your symptoms go away. Sometimes, symptoms improve quickly. Other times, it can take weeks or months for symptoms to go away.

Some people continue to have symptoms, like pain or feeling very tired, for months or even longer after treatment. This is called "post-treatment Lyme disease syndrome." It is also sometimes called "chronic" Lyme disease. But there is no good evidence that the infection is still in the body or that more antibiotics help.

What if I am pregnant? — 

Talk to your doctor. Some medicines for Lyme disease are safe to take while you are pregnant, but others might not be.

How can I prevent Lyme disease? — 

The best way to prevent Lyme disease is to avoid getting bitten by a tick. But if you were already bitten, your doctor might give you antibiotics. In some situations, this can reduce your chances of getting Lyme disease.

To try to avoid getting bitten by a tick, you should do the following:

●Wear shoes, long-sleeved shirts, and long pants when you go outside. Tuck your pants into your socks.

●Wear light colors so you can see any ticks on your clothes.

●Wear bug repellent that protects against ticks, such as a spray or cream containing DEET. But talk to your doctor or nurse about using DEET on children. For example, DEET should not be used on babies younger than 2 months, and experts suggest not using products with more than 30 percent DEET on other young children.

On your clothes and gear, you can use bug repellents that have a chemical called "permethrin."

●If you were outside in a place where they might be ticks, take a shower within 2 hours.

●After being outside, put dry clothes briefly (for about 4 minutes) in a dryer on the hot setting.

●Check your clothes and body for ticks after being outside. Check your scalp, waist, armpits, groin, and backs of your knees. If you have children, check them, too.

●If you live in a place that has deer or mice nearby, take steps to keep those animals away. Deer and mice carry ticks.

If you find a tick on your body or on your child, use tweezers to grab it. Then, pull it out slowly and gently. After that, wash the area with soap and water.

You do not need to keep the tick. But knowing what it looked like can help your doctor decide about your treatment. Take a picture of the tick, or write down:

●Its color and size

●If it was attached to your skin or just resting on your skin

●If it was big, round, and full of blood

See your doctor or nurse if a tick has bitten you and you cannot get it off.

You should also call your doctor or nurse if you think you have had a tick attached for at least 36 hours (a day and a half). They can decide if you need to take antibiotics to help prevent Lyme disease. Doctors only recommend antibiotics to prevent Lyme disease in some situations. It depends on your age, where you live, what kind of tick bit you, and how long it was attached.

If you or your child was bitten by a deer tick, watch the area around the bite for a month to see if a rash appears.

When should I call the doctor? — 

If you have been treated for Lyme disease, call your doctor or nurse if:

●Your symptoms do not improve.

●You develop new symptoms.

Your doctor might want to check to see if something other than Lyme disease could be causing your symptoms.

More on this topic

Patient education: Insect bites and stings (The Basics)

Patient education: Lyme disease prevention (Beyond the Basics)
Patient education: What to do after a tick bite to prevent Lyme disease (Beyond the Basics)
Patient education: Lyme disease symptoms and diagnosis (Beyond the Basics)
Patient education: Lyme disease treatment (Beyond the Basics)