Lyme disease is an infection caused by the bacterium Borrelia burgdorferi. This bacterium is usually found in animals such as mice and deer. Ixodes ticks can pick up the bacteria when they bite an infected animal, then transmit it to a person, which can lead to Lyme disease.
Ticks live in grass and shrubs and attach themselves to a suitable host as it passes by. Ticks are small and can be hard to see. Immature ticks, or nymphs, are about the size of a poppy seed.
The majority of reported Lyme disease cases occur in the Northeast, upper Midwest, and Pacific coastal areas of the United States because these regions are where ticks tend to live. Though Lyme disease cases have been reported from all over, in 2005 the majority of cases were reported in:
- Connecticut
- Delaware
- Maine
- Maryland
- Massachusetts
- Minnesota
- New Hampshire
- New York
- New Jersey
- Pennsylvania
- Wisconsin
Some cases of Lyme disease have also been reported in Asia, Europe, and parts of Canada.
Signs and Symptoms
Lyme disease can affect the skin, joints, nervous system, and other organ systems. Symptoms, and their severity, can vary from person to person.
The symptoms of Lyme disease are often described as occurring in three stages, though not everyone experiences all stages:
- The first sign of infection usually is a circular rash, called erythema migrans, that appears within 1–2 weeks of infection but may develop up to 30 days after the tick bite. This rash often has a characteristic "bull's-eye" appearance, with a central red spot surrounded by clear skin that is ringed by an expanding red rash. It may also appear as an expanding ring of solid redness. It may be warm to the touch and is usually not painful or itchy. The bull's-eye rash may be more difficult to see on people with darker skin tones, where it may take on a bruise-like appearance. The rash usually resolves in about a month. Although this rash is considered typical of Lyme disease, many patients never develop it.
- Along with the rash, a person may experience flu-like symptoms such as swollen lymph nodes, fatigue, headache, and muscle aches. Left untreated, symptoms of the initial illness may go away on their own. But in some people, the infection can spread to other parts of the body. Symptoms of this stage of Lyme disease usually appear within several weeks after the tick bite, even in someone who has not developed the initial rash. The person may feel very tired and unwell, or may have more areas of rash that aren't at the site of the bite.
Lyme disease can affect the heart, leading to an irregular heart rhythm or chest pain. It can spread to the nervous system, causing facial paralysis (Bell's palsy) or tingling and numbness in the arms and legs. It can start to cause headaches and neck stiffness, which may be a sign of meningitis. Swelling and pain in the large joints can also occur. - The last stage of Lyme disease may occur if early disease was not detected or appropriately treated. Symptoms of late Lyme disease can appear any time from weeks to years after an infectious tick bite and include arthritis, particularly in the knees, and, mainly in adults, cognitive deterioration.
Contagiousness
Lyme disease is not transmitted from person to person. The risk of developing Lyme disease depends on an individual's exposure to ticks. Kids and adults who spend a lot of time outdoors — particularly in or near wooded areas — are more likely to contract Lyme disease.
In rare cases, Lyme disease contracted during pregnancy may infect the fetus. If you are pregnant and are concerned about this, talk with your doctor.
Domestic animals, such as dogs and cats, may become infected with Lyme disease bacteria and may carry infected ticks into areas where humans live. If you have a dog or a cat, talk with your veterinarian about what kinds of tick-control products and other protective measures you can take for your pet.
Diagnosis
The most telling symptom of Lyme disease is the circular bull's-eye rash. Usually, because the rash is very distinct, a person with the rash can be immediately diagnosed with Lyme disease and blood tests are not necessary. Because the rash can rapidly disappear, consider taking a picture of any suspicious rash on your child if you are unable to see the doctor immediately.
In some cases, the bull's-eye rash never forms. In the absence of the rash, doctors must rely on other symptoms combined with an assessment of someone's likelihood of exposure to an infected tick. Blood tests can help diagnose Lyme disease by detecting the presence of antibodies to Borrelia burgdorferi in the patient's blood. However, blood tests can give inaccurate results if done within a month after initial infection, since it takes time for the antibodies to develop. Lyme disease can be difficult to diagnose because it may resemble many other medical conditions. Your doctor can help to decide whether your child needs a blood test for Lyme disease.
Treating Lyme Disease
Treatment of early localized Lyme disease typically involves a course of antibiotics administered for 3 to 4 weeks.
If diagnosed quickly and treated with antibiotics, Lyme disease in children is almost always treatable. The skin rash usually goes away within several days after starting treatment, but other signs and symptoms may persist for several weeks.
Prevention
Ticks frequently live in shady, moist ground cover and also cling to tall grass, brush, shrubs, and low tree branches. Lawns and gardens may harbor ticks, especially at the edges of woods and forests and around old stone walls (areas where deer and mice, the primary hosts of the deer tick, thrive).
To prevent Lyme disease, avoid contact with soil, leaves, and vegetation as much as possible, especially during May, June, and July, when ticks have not yet matured and are harder to detect.
When you do venture into the great outdoors, follow these tips:
- Wear enclosed shoes and boots, long-sleeved shirts, and long pants. Tuck pants into boots or shoes to prevent ticks from crawling up legs.
- Wear light-colored clothing to help you see ticks easily.
- Keep long hair pulled back or placed in a cap for added protection.
- When outside, don't sit on the ground.
- While outdoors, check yourself and your child frequently for ticks.
- Wash all clothes after leaving tick-infested areas, and bathe and shampoo your child thoroughly to eliminate any unseen ticks.
Insect repellents containing DEET (look for N,N-diethyl-meta-toluamide) can help to repel ticks. Choose one with a 10% to 30% concentration of DEET. Generally, DEET should not be applied more than once a day, and is not recommended for babies younger than 2 months. DEET can be used on exposed skin, as well as clothing, socks, and shoes, but should not be used on the face, under clothing, or on the hands of young children.
Ticks can bite anywhere, but they prefer certain areas of the body, such as:
- behind the ears
- the back of the neck
- armpits
- the groin
- behind the knees
If you find a tick on your child, call your doctor, who may want you to save the tick after removal (you can put it in a jar of alcohol to kill it). Use tweezers to grasp the tick firmly at its head or mouth, next to your child's skin. Pull firmly and steadily on the tick until it lets go, then swab the bite site with alcohol.
Myths abound about ways to kill ticks (such as using petroleum jelly or a lit match), but don't try them — these methods don't work.
You can help keep ticks away from your house by keeping lawns mowed and trimmed; clearing brush, leaf litter, and tall grass; and stacking woodpiles off the ground. In addition, you can have a licensed professional spray your yard with insecticide in May and September to prevent ticks from multiplying.
There is no vaccine for Lyme disease currently on the market in the United States.
When to Call the Doctor
If your child has a bull's-eye rash or other symptoms that can occur in Lyme disease — such as swollen lymph glands near a tick bite, general achiness, headache, or fever — call your doctor right away.