What Is Lyme Disease?
Lyme disease is an infection caused by a bacterial spirochete (a corkscrew-shaped organism) spread by a bite from an infected tick. It is named after the community of Old Lyme, Connecticut, where the disease was first identified. Lyme disease may affect several organ systems, and symptoms vary, some arising months or even years after a bite. Left untreated, the infection may affect the brain, heart, or joints, resulting in a type of chronic arthritis and fatigue.
The common deer tick carries the infection and is prevalent in New England, along both U.S. coasts, and in the upper Midwest. Deer ticks are small compared to dog ticks: Adults are the size of a pinhead; nymphs smaller still. Between 20% and 60% of ticks carry the bacteria, but infection is rare if the tick is removed within 48 hours of attachment. Lyme disease is preventable; it also responds well to treatment, especially if caught early. In some cases, it subsides spontaneously.
Who Gets Lyme Disease?
According to the Centers for Disease Control and Prevention (CDC), about 30,000 confirmed cases of Lyme disease are reported each year in the United States. It is endemic (prevalent) throughout the wooded coastal regions of the Northeast, the upper Midwest and Great Lakes region, and the Pacific Northwest. In the Northeast and Great Lakes regions, the disease is more prevalent from May to August. In the Pacific Northwest, it is more prevalent from January to May.
In August 2013, the CDC reported that the number of people infected with Lyme each year in the United States is actually about 10 times higher—300,000. Studies are ongoing to determine how many people are infected annually and how to prevent infection.
Symptoms can vary greatly from person to person. Early symptoms are usually mild and often overlooked.
- Within two to 30 days after a tick bite: a small, red, flat or slightly raised lesion at the site, surrounded by a round, bull’s-eyelike, red rash with a pale center. The rash may increase in size for some weeks before fading; similar lesions may appear at other sites. Other types of rash have been noted, some of which resemble hives, eczema, sunburn, poison ivy, and flea bites. Dark-skinned people may develop a rash that resembles a bruise. The affected area does not itch, but may feel warm to the touch. The rash occurs in about 90 percent of cases.
- Within 30 days: flulike symptoms of fever and chills, extreme fatigue, headaches, muscle and joint aches.
- Within several weeks or months (if not successfully treated): heart palpitations, shortness of breath, temporary facial paralysis, joint pain and swelling.
- Within two years: chronic joint pain and swelling, especially in knees (Lyme arthritis).
- Not all symptoms occur with every case or in any set order.
- For Lyme disease to develop, you must be bitten by a tick infected with the bacterium Borrelia burgdorferi. Ticks acquire the disease from infected mice and deer and may then transmit the bacteria to humans. Only deer ticks (also called blacklegged ticks) carry the disease—though not all deer ticks are infected. A bite does not always result in infection; the risk for developing Lyme disease increases the longer the tick is attached to your body.
- People who hike or spend time outdoors in wooded areas are at increased risk. Ticks wait on low vegetation in wooded areas and adjacent grasslands and transfer themselves to whatever brushes by; they don’t fly or jump.
- Dogs and cats can carry the ticks to your home and property. (Horses and household pets can get Lyme disease but cannot transmit it to humans; rather, they bring ticks close to humans.) If pet owners find a tick on their dog or cat, they should remove it by grasping the tick with fine-pointed tweezers and gently pulling it free. The more quickly the tick is removed, the lower the risk of disease transmission to the pet.
What If You Do Nothing?
Without treatment, Lyme disease can last anywhere from a few weeks to years. However, ignoring or delaying treatment can lead to chronic arthritis or heart problems, as well as skin and nervous system abnormalities that may be difficult to treat successfully. It’s clearly better to get yourself properly diagnosed and attend to the ailment as early as possible.
Diagnosis of Lyme disease is made based on clinical symptoms and case history.
Current antibody tests used to detect Lyme disease may be inconclusive, especially with early infection. As such, Lyme disease remains a clinical diagnosis to be made only by a physician.
A preserved tick may be examined to determine if it is the type that carries the infectious bacteria. When removing a tick, it should be removed carefully with fine tweezers, grabbing it as close to the skin as possible, and placed in a clean container with a moistened cotton swab. Squeezing the tick or applying petroleum jelly, a burnt match, or alcohol can transmit the bacteria through the skin and should be avoided.
- In areas where Lyme disease is prevalent, people should seek medical treatment if they are bitten by a tick that tests positive for Borrelia burgdorferi bacteria and symptoms develop. Women who are pregnant should seek prompt medical attention because the disease can be transmitted to the fetus.
- Early stage Lyme disease is treated with a 3- to 4-week course of antibiotics (e.g., amoxicillin, doxycycline, ceftriaxone), administered orally. Other antibiotics, given intravenously, may be needed to treat chronic arthritis or neurologic forms of the disease.
- OTC pain relievers reduce fever and inflammation.
- Currently, there is no approved vaccine for people in the United States, though drug manufacturers are currently working on development of one.
- When Lyme disease is diagnosed in its early stage, most patients are successfully treated with antibiotics. Humans do not develop immunity to Lyme disease and reinfection is possible. The disease is rarely, if ever, fatal.
Cover exposed skin when in grassy or wooded areas where ticks may be present. Tuck long pants into socks, wear shoes instead of sandals, and wear long-sleeved shirts. Light-colored clothing makes ticks easier to see.
Use an insect repellent containing DEET (diethyl-toluamide) or permethrin during outdoor summer activities.
Check skin, clothing, and pets for ticks after an outing. Ticks prefer dark, moist areas on people, typically the back of the knees, the groin area, and under the arms.
Pets should wear tick-repellent collars.
Use fine-tipped, curved tweezers to remove a tick attached to your skin. Grasp the tick as close to your skin as possible and pull steadily to remove it. Avoid squeezing the bloated abdomen, as this may inject bacteria into your skin or bloodstream. Do not touch the tick, because bacteria from a crushed tick may penetrate even unbroken skin. Preserve the tick by dropping it in rubbing alcohol. Wash your hands and apply antiseptic to the bite. Removing the tick within 36 hours will significantly reduce the risk for Lyme disease.
Do not use petroleum jelly, kerosene, or a lighted match or cigarette to remove the tick.
A new vaccine (OspA) has been approved for use in adults; it appears to decrease the transmission rate of Lyme by 80 percent following an infected bite. Persons living in an area where Lyme disease is known to be common can reduce their risk of developing Lyme disease if they take doxycycline within 72 hours of finding and removing a tick.
When To Call Your Doctor
Contact your physician if you think you may have contracted Lyme disease. You will also need to see your doctor if you want to be vaccinated against Lyme disease.
Robert Hurd, M.D., American Board of Internal Medicine and Professor of Endocrinology and Health Care Ethics, Xavier University, Cincinnati, OH. Review provided by VeriMed Healthcare Network.