What is Lyme disease?
Lyme disease is caused by a bacteria, Borrelia burgdorferi. The disease was first recognized in 1975 when large numbers of children were diagnosed with juvenile rheumatoid arthritis in Lyme, Connecticut, and two neighboring towns. Further research showed that bites from deer ticks infected with the bacterium were responsible for the outbreak of arthritis. Ordinary "wood ticks" and "dog ticks" do not carry the infection.
In the U.S., the Centers for Disease Control and Prevention estimates there are about 300,000 cases per year, even though the number reported is much lower.
Symptoms and Causes
What are the symptoms of Lyme disease?
Lyme disease may evolve through several phases or stages which can overlap causing symptoms that may involve the skin, joints, heart or nervous system.
Early Lyme disease typically causes a reddish rash or skin lesion known as erythema migrans (EM). The rash starts as a small red spot at the site of the tick bite 1 to 4 weeks after the bite. It expands over a period of days or weeks, forming a circular, triangular, or oval-shaped rash. The rash may look like a bull’s eye because it appears as a red ring that surrounds a clear center area.The rash can range in size from that of a dime to the entire width of a person's back. As infection spreads, several rashes (EM lesions) can appear at different sites on the body.
If the infection goes untreated, you may develop multiple areas of rash, paralysis of facial muscles (Bell’s palsy), heart block (interruption of the electrical system of the heart) or areas of numbness or abnormal sensation (neuropathy).
Untreated late Lyme disease, which occurs months to a year after the initial infection, is most commonly associated with recurring episodes of swollen joints (arthritis) typically of large joints such as the knee. Additionally some patients may develop difficulty concentrating, which is called “brain fog” (encephalopathy).
Diagnosis and Tests
How is Lyme disease diagnosed?
Lyme disease may be difficult to diagnose because many of its symptoms mimic those of other disorders. In addition, the only distinctive symptom of Lyme disease, the red rash, does not happen or is not noticed by one-fifth of those who become infected. Many people can’t recall having been bitten by a tick, because the tick is tiny, and its bite is usually painless.
If no rash is present, doctors will make the diagnosis on the basis of a detailed medical history, a careful physical examination, and laboratory tests to confirm their suspicion.
No test is perfect and the current testing for Lyme disease is no exception. Very early in the disease, testing will be negative as the body has not had time to develop a response that can be measured. Once the body responds, the positive test may persist for years even if Lyme is treated properly. Current research efforts are working to develop improved testing for Lyme disease.
Management and Treatment
How is Lyme disease treated?
Nearly all people with Lyme disease can be effectively treated with antibiotics, usually doxycycline or amoxicillin. The duration of treatment depends on the stage of infection. In general, the sooner such therapy is initiated following infection, the quicker and more complete the recovery.
Pregnant women should be treated for Lyme disease as well. There is, however, no evidence that a fetus can be infected from its mother. Additionally, NO strong evidence exists to suggest miscarriages are more likely after Lyme.
What should I do if I am bitten by a tick?
If you experience a tick bite, the best way to remove it is by taking the following steps:
- Tug gently but firmly with blunt tweezers near the "head" of the tick at the level of your skin until it releases its hold on the skin.
- Avoid crushing the tick's body or handling the tick with bare fingers as you could exposure yourself to the bacteria in the tick.
- Wash the bite area thoroughly with soap and water.
- DO NOT use kerosene, petroleum jelly (such as Vaseline®), or hot cigarette butts to remove the tick.
- DO NOT squeeze the tick's body with your fingers or tweezers.
Can Lyme disease be prevented?
Most people with Lyme disease become infected during the late spring, summer, and early fall when immature ticks are out feeding. Except in warm climates, few tick bites take place during winter months.
Deer ticks are most often found in wooded areas and nearby grasslands. They are especially common where the two areas merge, including neighborhood yards where deer occasionally roam. Ticks do not survive long on sunny lawns; they dry out quickly and die. Although only about 1% of all deer ticks are infected, there are areas in which over 50% of the ticks carry the bacterium. The diseased ticks are often found in the U.S. Northeast and upper Midwest areas.
The following tips can help you avoid tick bites:
- To repel ticks, you may want to spray your clothing with permethrin, an insecticide commonly found in lawn and garden stores. Insect repellents that contain a chemical called DEET can also be applied to clothing or directly onto skin. Read the labels carefully. Do not overuse, or they may cause harm.
- Minimize skin exposure to both ticks and insect repellents by wearing long pants and long-sleeved shirts that fit tightly at the ankles and wrists.
- Wear a hat, tuck your pant legs into socks, and wear shoes that leave no part of your feet exposed.
- Wear light-colored clothing to make it easier to detect ticks.
- Walk in the center of trails to avoid picking up ticks from overhanging grass and brush.
- After outdoor activity in an "at risk" area, always do a tick check and then shower, scrubbing with a washcloth.
- Get rid of any ticks on your clothes by putting them in the dryer for 15 minutes. This will kill any ticks attached to the clothes by drying them.
- Pets may bring ticks into the home. Discuss ways to prevent ticks on your pet with your veterinarian.
Outlook / Prognosis
What is the outlook for someone with Lyme disease?
Most of the people who get Lyme disease and treated early will be fine.
Even after proper treatment, some patients (estimated at 5-15%) may experience lingering fatigue, achiness or headaches. This does not signify ongoing infection and will not respond to additional antibiotics. The majority of people in this group will have symptoms resolve over the next 1-6 months.
Chronic Lyme Syndrome
Chronic Lyme syndrome is a term used by some that includes the symptoms of Post-Lyme syndrome outlined above. This is a controversial topic with no accepted etiology and no proven cause or association.