Lyme Disease

What is Lyme disease?

Lyme disease is a bacterial disease transmitted by infected ticks. It was first recognized in the United States in 1975 after a mysterious outbreak of arthritis near Old Lyme, Connecticut. Since then, reports of Lyme disease have increased dramatically, and the disease has become an important public health problem.

How does a person get Lyme disease?

Lyme disease is transmitted by the bite of an infected deer tick, which also is known as the black-legged tick. (Not all ticks carry the bacterium, and a bite does not always result in the development of Lyme disease. However, since it is impossible to tell by sight which ticks are infected, it is important to avoid tick bites whenever possible.) Immature deer ticks can be very small, about the size of the head of a pin; adult deer ticks are slightly larger. Both can be infected with and transmit Lyme disease. Deer ticks acquire the bacteria by feeding primarily on small mammals infected with the bacteria, particularly the white-footed mouse. (Domestic animals can become infected with the Lyme disease bacteria and some may develop arthritis, e.g., dogs, cattle and horses.)

(Click on image for a
larger view)Deer Ticks
Image source: Centers for Disease Control and Prevention

Deer ticks infected with the bacteria that cause Lyme disease have been found in Illinois. Areas in the United States where deer ticks are most frequently infected with Lyme disease are the northeastern United States (from Massachusetts to Maryland), northern California, and north central states, especially Minnesota and Wisconsin. However, Lyme disease has been reported in almost all states in the United States as well as in many countries throughout the world.

What are the symptoms of Lyme disease?

Signs and symptoms can vary greatly from one person to another. Symptoms also vary with the length of time a person has been infected. A ring-like red rash occurs in about 70 - 80 percent of cases and begins three days to 32 days after the bite of an infected tick. The red rash at the bite site is circular and grows larger over a few days or a few weeks. In the center, the rash usually clears and has been described as resembling a bull's-eye. Generally, the rash is not painful. Often this rash is accompanied by one or more nonspecific symptoms: fatigue, chills and fever, headache, swollen lymph nodes, and joint and muscle pain. An allergic reaction to tick saliva can often occur at the site of the tick bite. Such allergic reactions, which are not a sign of Lyme disease, usually occur within 72 hours after the tick bite, usually do not expand beyond 2 inches in diameter like the Lyme rash and disappear within a few days.

Some people are not diagnosed with Lyme disease in its initial stages because early symptoms are similar to those of more common diseases, such as a flu-like illness without a cough or mononucleosis, and many infected persons do not recall a tick bite. Day, weeks, months or years later other symptoms can develop if the disease is not diagnosed and treated. These include fever, severe headache and stiff neck, certain heart irregularities, temporary paralysis of facial muscles, pain with numbness or weakness in the arms or legs, loss of concentration or memory problems, and, most commonly, Lyme arthritis.

When should I seek a physician's care after a tick bite?

If you experience a rash or any unexplained illness accompanied by fever following a tick bite, you should consult your physician and explain that you were bitten by a tick.

Can Lyme disease be treated?

Yes. Treatment of Lyme disease consists of administration of the appropriate antibiotics. Oral antibiotics are usually used; however, intravenous antibiotics may be used if the disease has gone untreated or is difficult to control. The selection and use of an antibiotic varies depending on the patient's symptoms and whether he or she is treated early in the infection.

How do I avoid getting bitten by a tick?

The best way to protect yourself against Lyme disease and other tickborne illnesses is to avoid tick bites. This includes avoiding tick-infested areas. However, if you live in or visit wooded areas or areas with tall grass and weeds, follow these precautions against Lyme disease and other tickborne diseases like Rocky Mountain spotted fever, ehrlichiosis and tularemia:

  • Wear light-colored, protective clothing—long-sleeved shirts, long trousers, boots or sturdy shoes, and a head covering. Tuck trouser cuffs in socks. Tape the area where pants and socks meet so ticks cannot crawl under clothing.

  • Apply insect repellant containing 10 percent to 30 percent DEET primarily to clothes. Apply sparingly to exposed skin (do not spray directly to the face; spray the insect repellant onto hands and then apply to face. Avoid sensitive areas like the eyes, mouth and nasal membranes). Be sure to wash treated skin after coming indoors. Use repellents containing permethrin to treat clothes (especially pants, socks and shoes)—but not skin. Always follow label directions; do not misuse or overuse insect repellents. Always supervise children in the use of insect repellents.

  • Walk in the center of trails so weeds do not brush against you.

  • Check yourself, children and other family members every two to three hours for ticks. Most ticks seldom attach quickly and rarely transmit a tickborne disease until they have been attached for four or more hours. If your pets spend time outdoors, regularly check them for ticks, too.

  • Remove any tick promptly. Do not burn the tick with a match or cover it with petroleum jelly. Do not use bare hands. The best way to remove a tick is to grasp it with tweezers as close to the skin as possible and gently, but firmly, pull it straight out. Do not twist or jerk the tick. If tweezers are not available, grasp the tick with a piece of tissue or cloth or whatever can be used as a barrier between your fingers and the tick. If the mouthparts do break off, do not become alarmed; once the mouthparts are removed from the rest of the tick, the tick can no longer transmit the Lyme disease bacteria. If you want to have an intact tick identified, put it in a small vial of rubbing alcohol and contact your local health department for assistance.

  • Wash the bite area and your hands thoroughly with soap and water, and apply an antiseptic to the bite site.

  • Make sure the property around your home is unattractive to ticks. Keep your grass mowed and keep weeds cut.

idph online home
idph online home

Illinois Department of Public Health
535 West Jefferson Street
Springfield, Illinois 62761
Phone 217-782-4977
Fax 217-782-3987
TTY 800-547-0466
Questions or Comments