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Lyme Disease

• Definition of Lyme Disease
• Description of Lyme Disease
• Symptoms of Lyme Disease
• Diagnosis of Lyme Disease
• Treatment of Lyme Disease
• What Questions To Ask Your Doctor About Lyme Disease
• Prevention of Lyme Disease

Definition of Lyme Disease

Article updated and reviewed by David Aronoff, M.D., Assistant Professor, Division of Infectious Diseases, University of Michigan Medical School on May 9, 2005.

Lyme disease is a bacterial infection, caused by the spirochete Borrelia burgdorferi and acquired through tick bites.

Description of Lyme Disease

In 1975, Lyme disease was discovered in Old Lyme, Connecticut. Parents were perplexed by the high incidence of arthritis among their children and called for an investigation; this revealed that the children were suffering from a "new" disease.

Today, Lyme disease is the most common tick-transmitted disease in the world. There are roughly 20,000 new cases of Lyme disease in the United States each year. Although sporadic cases are reported in many states, Lyme disease primarily occurs in three distinct regions: in the Northeast from Massachusetts to Maryland, in the Midwest in Wisconsin and Minnesota, and in the West in northern California. Lyme disease is quite seasonal due to the life cycle of the tick. In the Northeast and Midwest, disease generally begins to appear between May 1 and October 30, with the majority of cases occurring in June and July. In California, the disease occurs throughout the year, with a slight increase in the summer months.

The two species of ticks known to transmit the disease are the deer tick Ixodes scapularis (also called Ixodes dammini) in the northeastern and midwestern United States, and Ixodes pacificus in the West. Ticks live in wooded and grassy areas and survive by attaching to animal hosts and sucking their blood. They attach to deer, field mice, other wild animals and humans, as well. Ixodes pacificus also feeds on birds and cold blooded animals, such as lizards. Other ticks, such as the common dog tick, do not transmit Lyme disease.

With a better understanding of the symptoms of Lyme disease, we now know it is not the "great imitator" of disease it once was thought to be. A limited number of identifiable syndromes can be related to Lyme disease.

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Symptoms of Lyme Disease

Human Lyme borreliosis generally occurs in stages, with remissions and exacerbations and different symptoms at each stage. The first stage of Lyme disease is a rash known as erythema migrans (EM), which usually occurs several days to a month after the tick bite, and consists of a small red lesion that later expands to form a ring-shaped rash - "bull's eye" - a bright red ring encircling the bite and a clear area at the center. This rash varies in size - it can be as small as a dime or it can cover a person's entire back; it usually marks the site of the bite or it can appear with several others throughout the body.

Flu-like symptoms, such as headaches, stiff neck, muscle aches and fatigue may also be present. About half of all infected people never develop the rash, making it more difficult to diagnose the illness.

If left untreated, Lyme disease can progress to a second stage of the disease, which occurs within the next several weeks. This disseminated infection involves joint pain and may bring about complications in the nervous system or the heart. Neurologic complications, such as inflammation of the brain and its covering membranes and inflammation of the nerve roots and facial paralysis, occur in about 15 percent of all patients. Symptoms may last several months, but usually disappear completely.

Heart disease symptoms occur in about 8 percent of the patients, and include dizziness, shortness of breath and an irregular heart rhythm. Generally, they disappear completely within weeks.

Arthritis may progress in stage 3 of the disease (persistant infection). Joint pain may appear weeks or even years after the rash, and it affects more than 50 percent of the patients. The large joints - knees, shoulders, elbows, ankles and wrists - are usually involved. They become swollen and painful. The first attack usually lasts about a week, but recurrent attacks are quite common. At this stage, a small number of people may also develop neurologic abnormalities, such as somnolence (drowsiness), loss of memory, mood swings and inability to concentrate.

The first attack usually lasts about a week, but recurrent attacks are quite common. At this stage, a small number of people may also develop neurologic abnormalities, such as somnolence (drowsiness), loss of memory, mood swings and inability to concentrate.

Diagnosis of Lyme Disease

Due to the variety of symptoms, a diagnosis cannot always be made quickly and accurately. If the patient knows about a recent tick bite, and demonstrates a classic rash described above, a straightforward diagnosis can be made and the most difficult part is over.

Unfortunately, because of the small size of the nymphal I. scapularis tick, the inciting bite often goes undetected. If Lyme disease is suspected, the physician can order a blood test to check for infection. The blood test, however, may be negative during the early phases of the disease, and false positives have been known to occur. Specialized tests to identify the genetic material of Borrelia burgdorferi within arthritic joints may aid in the diagnosis of Lyme arthritis.

Difficulty in diagnosing Lyme Disease is compounded because in addition to failure in spotting a tick bite and the absence of a rash, other ailments - such as systemic lupus erythematosus or rhematoid arthritis - are sometimes wrongly labeled as Lyme disease. Moreover, leptospirosis and syphilis, also caused by spirochetes, can misleadingly give lab results similar to those of Lyme disease.

Treatment of Lyme Disease

The various manifestations of Lyme disease are generally treatable with oral antibiotic therapy, except for objective neurologic abnormalities, which require intravenous therapy. Lyme arthritis can be treated successfully in most patients by a number of alternative antibiotics including tetracycline, doxycycline, erythromycin or amoxicillin. Response, however, is often delayed until many weeks after completion of the course, which suggests that noninfectious inflammatory mechanisms (perhaps involving uncleared antigenic material) can contribute to the perpetuation of arthritis in many patients. Another 10 percent or 15 percent respond to a second course of a different oral antibiotic or to a course of parenteral antibiotic therapy. The earlier the disease is treated, the shorter and less severe the symptoms will be.

Arthritis in advanced Lyme disease requires doxycycline, 100 mg orally twice a day for 30-60 days; amoxicillin, 500 mg four times a day for 30-60 days; or ceftriaxone, 2 g/d IV, in one or two doses, for 14 to 28 days. The addition of corticosteroids to the regimen is not recommended. If an arthritic patient fails to respond to oral medication, IV antibiotic therapy should be considered.

The diagnosis and treatment of Lyme disease presents numerous obstacles. People can be bitten by a tick without knowing it, and even when the bite is noticed, all ticks are not infected. The red circular rash around the bite, the telltale sign of an infected tick, does not always appear. Furthermore, Lyme disease symptoms mimic other diseases, such as fibromyalgia and multiple sclerosis, and no tests can reliably identify the presence of Borrelia burgdorferi.

Patients younger than 9 years or age, or pregnant or lactating women, are treated with amoxicillin or penicillin because doxycycline can stain the permanent teeth developing in young children or unborn babies. Patients allergic to penicillin are given erythromycin.

Lyme disease patients with neurological symptoms are usually treated with the antibiotic ceftriaxone, which is given intravenously once a day for a month or less. Most patients experience full recovery.

Lyme disease patients experiencing heart symptoms are treated with antibiotics, such as ceftriaxone or penicillin, given intravenously for about two weeks. If these symptoms persist or are severe enough, patients may also be treated with corticosteriods or given a temporary internal cardiac pacemaker. People with Lyme disease rarely experience long-term heart damage.

Following treatment for Lyme disease, some people continue to have persistent fatigue and achiness. This general malaise can take months to subside, although it generally does so spontaneously without requiring antibiotic therapy.

What Questions To Ask Your Doctor About Lyme Disease

Is Lyme a definite diagnosis or suspected as one of the possible diagnoses?

Have the lab tests detected the antibodies?

How long a course of treatment should be expected?

Are there other symptoms, such as joint pain, fatigue, dizziness, shortness of breath, or irregular heartbeat that I should be aware of?

Will the disease be cured?

Will all of the symptoms go away after treatment and cure?

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Editorial review provided by VeriMed Healthcare Network.

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Prevention of Lyme Disease

No FDA approved vaccine to prevent Lyme disease is presently available.

The best way to prevent Lyme disease is to avoid areas that are known to contain ticks, especially during the summer months. If you are going into wooded or grassy areas, wear light-colored clothing that fits tightly around the ankles and wrists, and tuck the pants into boots or socks. Spray your clothing with tick repellent. When you return, examine your body and clothing for ticks - they are very small, so look carefully.

How to remove an attached tick

Ticks are best removed as soon as possible, because the risk of Lyme disease transmission increases significantly after 24 hours of attachment. Brush off any ticks that are not attached and use tweezers to remove those that are. To remove them, grasp the tick's mouth-parts as close to the skin as possible, and use a slow steady pressure while pulling straight out. Don't attempt to jerk the tick out. Try not to squeeze the tick's body or tear the skin. If the tick’s mouthparts remain in the skin, however, don’t worry - the bacteria that causes Lyme disease is located in the tick’s belly. After removing the tick, always wash the area immediately with soap and water, alcohol or antiseptic.

Pets should be checked as they come into the house.

Other popular tick-removal tactics - such as butter, fingernail polish, gasoline, kerosene, petroleum jelly, rubbing alcohol, and lit matches or cigarettes - are usually ineffective and can even be hazardous.

Many ticks are disease free, so a tick bite does not mean you will automatically develop Lyme disease. If any possible symptoms develop, report them promptly to your physician.