Lyme Disease

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

Description

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. Most cases are concentrated in the coastal Northeast, Wisconsin, Minnesota, Northern California and Oregon. On the East Coast, 80 percent of the cases occur between May and August; July is the peak month of incidence. 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 Ixodes scapularis (the Western Black-legged Tick) and the Ixodes dammini (found in the eastern part of the country). 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. The Western Black-legged Tick also feeds on birds and cold blooded animals, such as lizards.

Recent research indicates that the spirochete has also been found in horse flies, deer flies, mosquitoes and fleas, but it is not yet clear whether they can transmit the disease to humans like the tick can. Other ticks, such as the common dog tick, do not transmit Lyme disease.

Known as "The Great Imitator," Lyme disease has numerous disguises that may allow it to slip through medical exams without being detected. The list of symptoms it is known to cause has been expanding as researchers get a better understanding of the short and long-term effects of this deceptive disease.

Symptoms

The first sign of Lyme disease usually occurs several days or a month after the tick bite, and consists of a small red pimple 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 may mark 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.

The second stage of the disease, which occurs within the next several weeks, 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. 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.

Diagnosis

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

Unfortunately, the 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.

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

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 terapy. 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 28 days; amoxicillin, 500 mg three times a day, plus probenecid, 500 mg three times a day for 28 days; or ceftriaxone, 2 g/d IV, in one or two doses, for 14 to 21 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.

Prevention

Since 1998, there has been a new vaccine for Lyme disease called LYMErix®. Given in three doses over a one-year period, this vaccine has been shown to provide from up to 78 percent protection (after all three doses) against this infection. Research is currently underway as to the optimal dosing schedule for the vaccine, but individuals 15 to 17 years old whose exposure to ticks is frequent and who live or travel in regions of the country where Lyme disease is common should consider receiving this vaccine if they perceive their risk to be substantial.

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. Brush off the ones 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 remains 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.

Questions To Ask Your Doctor

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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Lyme Disease