Lyme Disease

Lyme disease is an infection with a corkscrew-shaped bacteria called Borrelia burgdorferi. It is passed to humans through tick bites.

What is going on in the body?

After an infected tick bites an individual, the Borrelia burgdorferi organism can cause early local Lyme disease. This may cause a mild flu-like illness and a rash at the site of the bite. If the organism spreads through the body by the bloodstream, it can affect many body systems. This widespread infection is known as disseminated Lyme disease.

What are the causes and risks of the infection?

Lyme disease is caused by Borrelia burgdorferi. This bacteria is carried by certain species of ticks, including the following:

A person in these areas increases his or her risk of acquiring Lyme disease from a tick bite with the following activities:

Lyme disease can also be passed to an unborn child if the baby's mother has the disease during pregnancy.

What are the signs and symptoms of the infection?

Early local Lyme disease often starts with a mild flu-like illness. The person may complain of the following symptoms:

The most obvious sign of Lyme disease is the bull's-eye rash, commonly at the site of the tick bite. The rash may begin the day of the bite, or up to 30 days later. It starts as a red, circular lesion, which may feel hot and itchy. As it gets bigger, the center often clears. The skin looks normal in the middle, making the lesion resemble a bull's-eye on a dartboard.

The lesion may grow to over 20 inches in diameter. Within a few days, more lesions may erupt. In 3 to 4 weeks, the lesions are replaced by small red blotches, which may continue for several weeks.

Lyme disease may spread to other body systems, causing disseminated Lyme disease. General symptoms of disseminated Lyme disease include:

Depending on the body systems involved, disseminated Lyme disease may also cause:

These symptoms tend to come and go over a number of weeks if the person is not treated.

Weeks to years later, frank, or unmistakable, arthritis can occur, with marked swelling of the joints. Recurrent attacks can lead to chronic arthritis, with severe joint damage.

How is the infection diagnosed?

Early Lyme disease is usually diagnosed by the presence of the bull's-eye rash. An antibody titer blood test is often done to confirm the diagnosis. The spirochetes that cause Lyme disease can also be cultured from blood or a biopsy of the rash. However, the culture is difficult and often takes months to complete.

What can be done to prevent the infection?

People can prevent Lyme disease by avoiding tick bites. Here are several tips to help avoid tick bites.

Some individuals should consider getting immunized with a new vaccine that appears to be effective in preventing Lyme disease. The vaccine is given to individuals aged 15 to 70 years in three separate injections. People in areas where Lyme disease is very common will find it of greatest use. The vaccine does not always work, though, so people still need to follow the other protective measures.

A recent study has shown that a single dose of the antibiotic doxycycline, taken right after a bite from a deer tick, is highly effective in preventing Lyme disease. Researchers recommend limiting this antibiotic prevention to people in high-risk areas who have had a tick attached to their skin for a day or two. It should not be given to pregnant women or children under the age of 8 years.

What are the long-term effects of the infection?

Untreated Lyme disease may cause permanent disabilities from arthritis, meningitis, stroke, and nerve damage.

What are the risks to others?

Lyme disease is not directly contagious from person to person. However, people with untreated Lyme disease can pass it on by donating blood. A pregnant woman with Lyme disease can pass the infection to her unborn child.

What are the treatments for the infection?

Lyme disease is treated with antibiotics, including the following:

Other medications may be used to treat symptoms of Lyme disease. For example, seizures may be treated with anticonvulsant medications. Ibuprofen may be given for fever or joint pain.

What are the side effects of the treatments?

Antibiotics and other medications used to treat Lyme disease may cause stomach upset or allergic reactions. Some of the antibiotics may cause light sensitivity.

What happens after treatment for the infection?

With effective treatment, individuals recover from Lyme disease without further problems. In some individuals, the disease lasts a long time or the infection comes back. These people may need repeated treatment. There is currently controversy about the effectiveness of long term antibiotics for chronic Lyme disease. Research continues in this area.

How is the infection monitored?

Any new or worsening symptoms should be reported to the healthcare provider.

Author:Danielle Zerr, MD
Date Written:
Editor:Ballenberg, Sally, BS
Edit Date:06/30/01
Reviewer:William M. Boggs, MD
Date Reviewed:06/19/01