Ticks and Lyme Disease
What is Lyme disease?
Lyme disease is an infection caused
by the bacteria Borrelia burgdorferi. This spiral shaped bacterium is most commonly
spread by a tick bite. The disease takes its name from Lyme, CT. This is where the
illness was first identified in the U.S. in 1975.
Lyme disease is a year-round
problem. But April through October is generally the most active tick season. Cases of
Lyme disease have been reported in nearly all states in the U.S. and in large areas in
Europe and Asia. But the most common areas are the Northeast, upper Midwest, and
What causes Lyme disease?
Lyme disease is caused by bacteria
that is spread to humans by tick bites. The ticks that carry the bacteria are:
- Black-legged deer tick (northeastern, mid-Atlantic, and North-Central U.S.)
- Western black-legged tick (Pacific coastal U.S.)
Ticks prefer to live in wooded
areas, low-growing grasslands, and yards. Not all ticks carry the Lyme disease bacteria.
Depending on the location, anywhere from less than 1 in 100 to more than half of the
ticks are infected with it.
While most tick bites are harmless, several species can cause life-threatening diseases. Tick-borne diseases include:
- Rocky Mountain spotted fever
- Lyme disease
- Colorado tick fever
- Powassan encephalitis
- Relapsing fever
Who is at risk for Lyme disease?
Factors that can increase your risk for getting Lyme disease include:
- Working or spending time outdoors in
grassy areas where the black-legged deer tick or Western black-legged deer tick is
- Having pets that can bring the ticks into the home
What are the symptoms of Lyme disease?
Many people infected with the Lyme
bacteria will never have symptoms. Their bodies will cure the infection without needing
any treatment. If the infection causes symptoms, the following are the most common ones
that people have. They vary based on how long the person has had the infection.
The primary symptom is a red rash that:
- Can appear several days after infection, or not at all
- Can last up to several weeks
- Can be very small or grow very large (up to 12 inches across), and may resemble a “bulls-eye”
- Can mimic such skin problems as hives, eczema, sunburn, poison ivy, and flea bites
- Can itch or feel hot, or may not be felt at all
- Can disappear and return several weeks
Several days or weeks after a bite
from an infected tick, you may get the rash again. When the rash returns, it often
affects many parts of the body. You may also have flu-like symptoms, such as:
- Stiff neck
- Aches and pains in muscles and joints
- Low-grade fever and chills
- Tiredness (fatigue)
- Poor appetite
- Swollen glands
Weeks to months after the bite, you
- Nervous system symptoms, including
inflammation (meningitis) and weakness and paralysis of a facial nerve (Bell
- Heart problems, including inflammation of the heart (myopericarditis) and problems with heart rate
- Eye problems, including inflammation (for example, red eye)
Months to a few years after a bite,
you may have:
- Inflammation of the joints (arthritis)
- Nervous system symptoms, such as
numbness in the arms or legs, tingling and pain, and trouble with speech, memory, and
How is Lyme disease diagnosed?
Sometimes diagnosing Lyme disease
can be hard. The symptoms may seem like other health problems. It may also not be known
if the person was exposed to ticks.
Diagnosis is usually based on
symptoms, particularly the typical rash of Lyme disease, along with a history of a known
or possible tick bite. At the time of the first rash, testing is still negative and not
helpful. For later symptoms, blood testing may be done to confirm the diagnosis and rule
out other conditions.
The symptoms of Lyme disease may
look like other health problems. And other problems can be mistakenly diagnosed as Lyme
disease. Always talk with your healthcare provider for a proper diagnosis.