Lyme Disease and Related Tick-Borne Infections - Highlights

Highlights

Causes

Lyme disease is caused by the bacterium Borrelia (B.) burgdorferi, which is transmitted through the bite of a deer tick. Either nymph or adult ticks can transmit B. Burgdorferi.

Risk Factors

• Anyone exposed to deer ticks is at risk for Lyme disease. Deer ticks thrive in grassy areas that have low sunlight and high humidity.
• Nymph ticks are more active during the summer months, and their small size makes them more difficult to spot than adult ticks. Consequently, the risk for acquiring Lyme disease tends to be higher during the summer than the spring or fall. Risk is lowest in the winter when ticks become inactive.

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Prevention

• Avoid tick-infested areas such as tall grass, woods, and bushes.
• If walking or hiking through these areas, wear long pants and long sleeves. Light-colored clothes will make it easier to spot ticks.
• Use a tick repellant (DEET, picardin) on your exposed skin and clothes. Spray your clothes with permethrin (but NOT your skin).
• After you return home, do a tick check. Removing infected ticks within 48 hours of attachment significantly reduces the risk of developing Lyme disease.

Symptoms

• A bull's eye rash, called erythema migrans, is the most definitive sign of Lyme disease infection. This rash usually develops 1 - 2 weeks after the tick bite.
• Other symptoms, such as joint pains, fever, chills, and fatigue, may accompany the rash.
• If Lyme disease is not treated, more severe symptoms and complications can occur. These may include arthritis, neurologic symptoms, and heart problems.

Treatment

Most cases of Lyme disease can be prevented or cured with prompt antibiotic treatment following a deer tick bite. If a preventive antibiotic is needed, a single dose of doxycycline may suffice. To treat active disease, antibiotics are usually given for 2 - 4 weeks. Current guidelines do not recommend longer courses of antibiotic treatment for any stage or complication of Lyme disease.

Review Date: 01/13/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org).