What is Lyme disease?

Lyme disease is an infection your child can get after being bitten by a carrying a certain type of bacteria (Borrelia burgdorferi). The disease is named for the Connecticut town where the illness was first identified in 1975.

But unless you live in an , the chances of your child getting Lyme are slim because most ticks aren't infected. (Only blacklegged ticks transmit the infection, and not all blacklegged ticks are infected.)

Even if an infected tick does bite your child, it has to stay embedded in his skin for a significant time (usually more than 36 hours) for your child to contract the disease.

But that doesn't mean you shouldn't take precautions – untreated Lyme disease can be serious. Fortunately, you can take steps to prevent the illness, and it responds well to treatment once it's diagnosed.

How common is Lyme disease?

The incidence of Lyme disease in the United States has increased from about 16,000 cases annually in 1996 to about 36,000 annually in 2016. And these are only cases reported to the Centers for Disease Control and Prevention (CDC) by state health departments, which means they're only a fraction of actual cases.

Studies published by the CDC in 2014 and 2015 suggest that the number of people diagnosed with Lyme disease each year in the United States is actually around 300,000. Boys between ages 5 and 9 make up the largest number of cases.

Cases have been diagnosed in virtually every state in the country, but the disease is most common in the Northeast and the Upper Midwest.

According to the CDC, 95 percent of confirmed Lyme disease cases in 2015 were reported from 14 states: Connecticut, Delaware, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Virginia, and Wisconsin. Infected ticks can also be found in nearby states and in some areas of Northern California, Oregon, and Washington.

Lyme disease isn't the only reason to avoid ticks – they can cause more than a dozen other diseases, including anaplasmosis, babesiosis, Rocky Mountain spotted fever, Southern tick-associated rash illness (STARI), tularemia, and 364D rickettsiosis.

What are the symptoms?

Doctors call Lyme disease the "great imitator" because it mimics other diseases, making it difficult to diagnose.

About 70 to 80 percent of the time, symptoms include a telltale rash that can appear anywhere on the body. The rash typically appears from three days to one month after the bite. It may be a solid red expanding blotch, or look like a central oval or round red spot surrounded by clear skin and then a ring of an expanding red rash, resembling a bull's-eye. On dark skin, the rash may simply look like a bruise.

The size of the rash area may start out at a fraction of an inch and grow to 6 or even 12 inches in diameter. It usually isn't painful or itchy, but it may be warm to the touch and persist for three to five weeks.

Don't panic if your child is bitten by a tick and has a small bump or an area of redness (like a mosquito bite) at the site. Although you'll want to keep an eye on this, it's probably just irritation from the tick bite that will disappear in a couple of days.

Other possible early symptoms (which can appear up to a month after the bite) include , , fatigue, muscle and joint aches, swollen lymph nodes, and other skin rashes.

The infection can also affect the joints, heart, and nervous system. Symptoms can show up years after being bitten and include:

  • Severe headaches
  • Neck stiffness
  • Other rashes
  • Arthritis (especially in large joints, like the knees)
  • Facial palsy (loss of muscle tone or droop on one or both sides of the face)
  • Pain in tendons, muscles, joints, and bones
  • Heart palpitations or an irregular heartbeat
  • Dizziness or shortness of breath
  • Nerve pain
  • Shooting pains, numbness, or tingling in the hands or feet
  • Short-term memory loss

What should I do if I find a tick on my child?

If the tick is crawling on your child's body and it's still small and flat, that means it hasn't become engorged from feeding on blood so there's no risk that your child has been infected. Just use a tissue to pick it up and then flush it down the toilet.

If you find a tick attached to your child's skin, remove it as soon as possible by pulling it out gently with tweezers. Firmly grasp it as close to the tick's mouth as you can. Then, without squeezing the body, pull it slowly and evenly away from the skin. Flush the tick down the toilet.

For more information, see our article on .

When should I call a doctor?

Call the doctor immediately if your child has a suspicious rash or other symptoms of Lyme disease.

Check in with the doctor if you find an engorged tick that you think may have been embedded in your child's skin for more than a day, especially if you live in an area where the condition is common.

In most cases, it's unlikely the doctor will prescribe an antibiotic preventively after a tick bite. But your child's doctor may recommend a single dose of doxycycline (given within 72 hours of the bite) to lower the risk of Lyme disease if:

  • You live in an area where Lyme disease is common.
  • The tick has been attached to your child for at least 36 hours.
  • The tick is confirmed to be the type that may carry Lyme disease.

How is Lyme disease diagnosed?

If your child has the distinctive rash, the doctor will probably be able to diagnose the condition based on that alone.

There is a blood test for Lyme disease, but it's unreliable in the early stages of the disease and generally isn't done. (It takes two to six weeks after the infection develops to get a positive test result.)

If your child's doctor does order a test, there are two steps. The preliminary test, called enzyme-linked immunoassay (ELISA), screens for an elevated blood level of antibodies produced by the body in response to the Lyme bacteria. If that test is positive, she may do a more specific and sensitive type of blood test (Western blot) to confirm the results.

How is Lyme treated?

Once diagnosed, Lyme disease is treated with oral antibiotics for three to four weeks or with intravenous antibiotics. The doctor may also have your child take an anti-inflammatory drug, such as , if she thinks your child may have joint pain.

Most children recover within a few weeks after taking antibiotics. Occasionally, symptoms like fatigue and muscle aches persist longer.

Is there a vaccine against Lyme disease?

Not at the moment. There was a vaccine, called LYMErix, although it was never approved for young children. The manufacturer pulled it from the market after some controversy about its safety. A new vaccine, however, is currently being tested in Europe.

How can I prevent my child from getting Lyme?

After you understand how your child could get the disease, you can take steps to prevent it. The prime season for Lyme disease is April through October, with the peak months in May, June, and July, when the ticks are active and not yet mature (so they're smaller and harder to see).

See our article on for detailed advice on how to avoid them.