Lyme disease is the most common tick-borne illness in North America and Europe. Lyme disease is caused by the bacterium Borrelia burgdorferi. Deer ticks, which feed on the blood of animals and humans, can harbor the bacteria and spread it when feeding.
You're more likely to get Lyme disease if you live or spend time in grassy and heavily wooded areas where ticks carrying the disease thrive. It's important to take common-sense precautions in areas where Lyme disease is prevalent.
If you're treated with appropriate antibiotics in the early stages of the disease, you're likely to recover completely. In later stages, response to treatment may be slower, but the majority of people with Lyme disease recover completely with appropriate treatment.
The signs and symptoms of Lyme disease are variable, usually involving more than one system. The skin, joints and nervous system are affected most often. In general, Lyme disease can cause:
Rash. A few days to a month before you have other symptoms, a small, red bump may appear at the site of the tick bite. Over the next few days, the redness expands, forming a rash in a bull's-eye pattern, with a red outer ring surrounding a clear area. The rash, called erythema migrans, is one of the hallmarks of Lyme disease. Some people develop several of these rashes, an indication of bacteria multiplying in the blood stream.
Flu-like symptoms. Fever, chills, fatigue, body aches and a headache may accompany the rash.
Migratory joint pain. If the infection is not treated, you may develop bouts of severe joint pain and swelling several weeks to months after you're infected. Your knees are especially likely to be affected, but the pain can shift from one joint to another.
Neurological problems. In some cases, inflammation of the membranes surrounding your brain (meningitis), temporary paralysis of one side of your face (Bell's palsy), numbness or weakness in your limbs, and impaired muscle movement may occur weeks, months or even years after an untreated infection.
Less common signs and symptoms. Some people may experience heart problems — such as an irregular heartbeat — several weeks after infection, but this rarely lasts more than a few days or weeks. Eye inflammation, hepatitis and severe fatigue are possible as well.
When to see a doctor
If you know you've been bitten and experience signs and symptoms of Lyme disease — particularly if you live in an area where Lyme disease is prevalent — contact your doctor immediately. Treatment for Lyme disease is most effective if begun early. Only a minority of deer tick bites leads to Lyme disease. The longer the tick remains attached to your skin, the greater your risk of getting the disease.
In the United States, the Lyme disease bacterium is carried primarily by deer ticks. The ticks are brown and often no bigger than the head of the pin, which can make them nearly impossible to spot.
Ticks attach themselves to a host and feed on the host's blood until they're swollen to many times their normal size. During feeding, ticks that carry disease-producing bacteria can transmit the bacteria to a healthy host. Or, if the host is infected, they may pick up bacteria themselves.
Deer ticks typically feed on the blood of mice, small birds and deer, but they can also feed on the blood of humans, cats, dogs and horses. They live in low bushes and tall grasses of wooded areas, waiting for warm-blooded animals to pass by. Deer ticks are most active in the summer.
To contract Lyme disease, you must be bitten by an infected deer tick. The bacteria enter your skin through the bite and eventually make their way into your bloodstream. Before bacteria can be transmitted, a deer tick must take a blood meal, which can take more than 48 hours of feeding. Only ticks that are attached to your skin and are feeding can transmit the bacteria. An attached tick that has a swollen appearance may indicate that enough time has elapsed to transmit bacteria. Removing the tick as soon as possible may prevent infection.
Where you live or vacation can affect your chances of getting Lyme disease. So can your profession and the type of outdoor activities you enjoy. The most common risk factors for Lyme disease include:
- Spending time in wooded or grassy areas. In the United States, deer ticks are most prevalent in the Northeast and Midwest regions and in northwestern states like Oregon and Washington. All have heavily wooded areas where deer ticks thrive. In these regions, children who spend a lot of time outdoors are especially at risk. So are people with outdoor occupations and those who live where mice are common. Deer ticks feed on mice, which are a prime reservoir for Lyme disease bacteria.
- Having exposed skin. Ticks attach easily to bare flesh. If you're in an area where ticks are common, protect yourself and your children by wearing long sleeves and long pants. Don't allow your pets to wander in tall weeds and grasses.
- Not removing ticks promptly or properly. Bacteria from a tick bite can enter your bloodstream only if the tick stays attached to your skin for 48 hours or longer. If you remove a tick within two days, your risk of acquiring Lyme disease is low.
- Chronic joint inflammation (Lyme arthritis), particularly of the knee
- Neurological symptoms, such as facial palsy and neuropathy
- Cognitive defects, such as impaired memory
- Heart rhythm irregularities
If you don't have the characteristic Lyme disease rash, your doctor may ask detailed questions about your medical history and do a physical exam. Lab tests to identify antibodies to the bacteria may be used to help confirm the diagnosis. These tests are most reliable a few weeks after an infection, after your body has time to develop antibodies. They include:
- Enzyme-linked immunosorbent assay (ELISA) test. The test used most often to detect Lyme disease, ELISA detects antibodies to B. burgdorferi. But because it can sometimes provide false-positive results, it's not used as the sole basis for diagnosis.
- Western blot test. If the ELISA test is positive, another test — the Western blot — is usually done to confirm the diagnosis. The Western blot detects antibodies to several proteins of B. burgdorferi.
- Polymerase chain reaction (PCR). This test helps detect bacterial DNA in fluid drawn from an infected joint. It's not as effective at detecting infection of blood or urine. It's used for people who may have chronic Lyme arthritis. It may also be used to detect persistent infection in the cerebrospinal fluid of people who have nervous system symptoms.
Oral antibiotics are the standard treatment for early-stage Lyme disease. These usually include doxycycline for adults and children older than 8, or amoxicillin or cefuroxime for adults, younger children, and pregnant or breast-feeding women. These drugs often clear the infection and prevent complications. A 14- to 21-day course of antibiotics is usually recommended, but some studies suggest that courses lasting 10 to 14 days are equally effective.
Intravenous antibiotics
If the disease has progressed, your doctor may recommend treatment with an intravenous antibiotic for 14 to 28 days. This is effective in eliminating infection, although it may take some time to recover symptomatically. Intravenous antibiotics can cause various side effects, including a lower white blood cell count, mild to severe diarrhea, or colonization or infection with other antibiotic resistant organisms unrelated to Lyme.
After treatment, a small number of people still experience some symptoms, such as muscle aches and fatigue. The cause of these continuing symptoms is unknown, but extended antibiotic treatment doesn't make them go away. Some experts believe that certain people who get Lyme disease are predisposed to develop an autoimmune response that contributes to their symptoms. More research is needed.
Avoid Bismacine
The Food and Drug Administration (FDA) warns consumers and health care providers to avoid Bismacine, an injectable compound prescribed by some alternative medicine practitioners to treat Lyme disease. Bismacine, also known as Chromacine, contains high levels of the metal bismuth. Although bismuth is safely used in some oral medications for digestive conditions, it's not approved for use in injectable form or as a treatment for Lyme disease. Bismacine can cause bismuth poisoning, which may lead to heart and kidney failure.
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