How Lyme Disease Is Diagnosed and Treated

by National Institute of Health

(Page 2 of 3)

Your health care provider may have difficulty diagnosing Lyme disease because many of its symptoms are similar to those of other disorders. In addition, the only distinctive sign unique to Lyme disease - the EM rash - is absent in at least one-fourth of the people who become infected.

The results of recent research studies show that an infected tick must be attached to the skin for at least 2 days to transmit Lyme bacteria. Although a tick bite is an important clue for diagnosis, many people cannot recall having been bitten recently by a tick. This is not surprising because the deer tick is tiny, and a tick bite is usually painless.

If you have possible Lyme disease symptoms, but do not develop the distinctive rash, your health care provider will rely on a detailed medical history and a careful physical examination for clues to diagnose it, with laboratory tests to support the diagnosis.

Blood Tests

The Lyme disease bacterium is difficult to find in laboratory tests of body tissues or fluids. Therefore, most health care providers look for evidence of antibodies against B. burgdorferi in the blood to confirm the bacterium's role as the cause of symptoms.

Some people with nervous system symptoms also may get a spinal tap. Using this procedure, your health care provider can detect brain and spinal cord inflammation and can look for antibodies or genetic material of B. burgdorferi in the spinal fluid.

Health care providers cannot always firmly establish whether Lyme disease bacteria are causing symptoms. In the first few weeks following infection, antibody tests are not reliable because your immune system has not produced enough antibodies to be detected. Antibiotics given early during infection also may prevent antibodies from reaching detectable levels, even though Lyme disease bacteria are causing your symptoms.

The antibody test most often used is called an ELISA (enzyme-linked immunosorbent assay) test. The Food and Drug Administration has approved two antibody tests: Prevue B, a rapid test, can give results within an hour and the C6 Lyme Peptide ELISA is very sensitive and specific.

If your ELISA is positive, your health care provider should confirm it with a second, more specific test called a Western blot.

Health care providers must rely on their clinical judgment in diagnosing Lyme disease if you don't have the distinctive EM rash. Such a diagnosis would be based on time of year, history of a tick bite, symptoms.

In addition, your health care provider will rule out other diseases that might cause your symptoms. Health care providers may consider factors such as whether your symptoms first appeared during the summer months when tick bites are most likely to occur, whether you were outdoors in an area where Lyme disease is common

New Tests Under Development

Health care providers need tests to distinguish between people who have recovered from previous infection and those who continue to suffer from active infection.

To improve the accuracy of Lyme disease diagnosis, National Institutes of Health (NIH) - supported researchers are re-evaluating existing tests and developing a number of new tests that promise to be more reliable than those currently available.

NIH scientists are developing tests that use the highly sensitive genetic engineering technique known as PCR (polymerase chain reaction) as well as microarray technology to detect extremely small quantities of the genetic material of the Lyme disease bacterium or its products in body tissues and fluids.

A bacterial protein, outer surface protein (Osp) C, is proving useful for early detection of specific antibodies in people with Lyme disease. Since the genome of B. burgdorferi has been sequenced, new avenues are available for improving understanding of the disease and its diagnosis.

How Lyme Disease Is Treated

Using antibiotics appropriately, your health care provider can effectively treat your Lyme disease. In general, the sooner you begin treatment following infection, the quicker and more complete your recovery.

Antibiotics such as doxycycline, cefuroxime axetil, or amoxicillin, taken orally for a few weeks, can speed the healing of the EM rash and usually prevent subsequent symptoms such as arthritis or neurologic problems. Doxycycline also will effectively treat most other tickborne diseases.

When Lyme disease occurs in children younger than 9 years, or in pregnant or breast-feeding women, they usually are treated with amoxicillin, cefuroxime axetil, or penicillin because doxycycline can stain the permanent teeth developing in young children or unborn babies.

Arthritis

If you have Lyme arthritis, your health care provider may treat you with oral antibiotics. If your arthritis is severe, you may be given ceftriaxone or penicillin intravenously (through a vein). To ease discomfort and to further healing, your health care provider might also give you antiinflammatory drugs, draw fluid from your affected joints, or surgically remove the inflamed lining of those joints.

In most people, Lyme arthritis will go away within a few weeks or months following antibiotic treatment. In some, however, it can take years to disappear completely. Some people with Lyme disease who are untreated for several years may be cured of their arthritis with the proper antibiotic treatment. If the disease has persisted long enough, however, it may permanently damage the structure of the joints.

Neurologic Problems

If you have neurologic symptoms, your health care provider will probably treat you with the antibiotic ceftriaxone given intravenously once a day for a month or less. Most people recover completely.

Heart Problems

Health care providers prefer to treat people with Lyme disease who have heart symptoms with antibiotics such as ceftriaxone or penicillin given intravenously for about 2 weeks. People with Lyme disease rarely have long-term heart damage.

Following treatment for Lyme disease, you might still have muscle achiness, neurologic symptoms such as problems with memory and concentration, and fatigue.

NIH-sponsored researchers are conducting studies to determine the cause of these symptoms and how to best treat them. Studies suggest that people who suffer from chronic Lyme disease may be genetically predisposed to develop an autoimmune response that contributes to their symptoms. Researchers are now examining the significance of this finding in great detail.

Researchers are also conducting studies to find out the best length of time to give antibiotics for the various signs and symptoms of Lyme disease.

Unfortunately, a bout with Lyme disease is no guarantee that the illness will not return. The disease can strike more than once if you are reinfected with Lyme disease bacteria.

About the Author

NIH is the nation's medical research agency - making important medical discoveries that improve health and save lives. The National Institutes of Health (NIH), a part of the U.S. Department of Health and Human Services, is the primary Federal agency for conducting and supporting medical research.