Spread by Deer Tick Bite

Lyme disease is a bacterial infection first described in 1975 in Old Lyme, Connecticut. Caused by the bacterium Borrelia burgdorferi, Lyme disease spreads to humans through the bite of an infected deer tick. The transfer of bacteria occurs when a tick bites an infected deer or mouse, then attaches to human skin and feeds over a period of 1 to 3 days. Lyme disease is most prevalent along the upper East Coast, as well as in the upper Midwest, where it is slowly spreading inland. It is also common in Northern California and the Oregon Coast.

Prompt Detection Paramount

Symptoms of Lyme disease appear within a few days up to a few weeks after the tick bite. Early symptoms resemble influenza, including fever, chills, headache, and muscle aches. In about 75% of cases, a bull’s-eye rash, known as erythema migrans, appears and has a red circle that spreads up to 12 inches in diameter with a clear circle near the center. As the disease progresses, symptoms become more severe and include joint, heart, and nerve problems over a period of weeks, months, and even years.

Curable With Antibiotics if Diagnosed Properly

Not surprisingly, many people who develop Lyme disease cannot recall being bitten by a tick. Laboratory testing begins with a blood test to look for antibodies to B burgdorferi, which may not appear in the blood until several weeks after the bacterial infection has occurred. A second blood test (sometimes referred to as a Western Blot test) may be used to confirm results from the initial test, if necessary.

Upon the confirmation of Lyme disease, physicians prescribe oral antibiotics. The recommended antibiotics include doxycycline, amoxicillin, and cefuroxime axetil. Doxycycline is not approved for use in children younger than 8 years and is contraindicated in pregnant and nursing women. Alternative antibiotics such as azithromycin, clarithromycin, or erythromycin may be used in patients who cannot take the recommended agents. The exact antibiotic and length of treatment depend on the duration and symptoms experienced by the patient. Rare but serious complications such as meningitis or heart inflammation are treated with IV antibiotics. Nonsteroidal anti-inflammatory drugs such as ibuprofen help relieve muscle and joint stiffness and pain.

Symptoms Persist in Some Patients

In most cases, Lyme disease symptoms disappear with antibiotic therapy, although a small percentage of patients will continue to have symptoms even after treatment, which is known as post-treatment Lyme disease syndrome. This may be caused by a continued reaction by the immune system for unknown reasons. Further treatment with antibiotics is not effective in these patients.

Preventing Tick Bites Is the Best Defense

Immature deer ticks often hide in shady, moist ground debris, but adults can be found above the ground, clinging to tall grass, brush, and shrubs. Ticks also inhabit lawns and gardens, especially at the edges of woodlands and around old stone walls where deer and white-footed mice thrive. The best way to prevent Lyme disease is to avoid contact with soil, fallen leaves, and vegetation as much as possible. However, if you garden, hike, camp, hunt, or work outdoors, you should use a combination of preventive methods to reduce your chances of getting Lyme disease, such as applying a strong tick repellent to the skin and wearing light-colored clothing to make the ticks easier to spot and enclosed shoes, long sleeves, and pants to limit exposed skin where ticks can attach.

Make it a habit to check the skin and scalp thoroughly for attached ticks after spending time outdoors. If a tick is found attached to the skin, it should be removed by pinching the head with tweezers and pulling straight up. Watch the area of the tick bite for several weeks for signs of a bull’s-eye rash or early symptoms of Lyme disease.

If you have questions about tick bites, Lyme disease, antibiotics used to treat Lyme disease, or tick repellents, your pharmacist can help.

To comment on this article, contact rdavidson@uspharmacist.com.