Lyme disease is the leading cause of vector-borne infectious illness in the U.S. with about 25,000
cases reported annually. The disease is also probably greatly underreported, so the true number of infected individuals may be much larger. Maryland is one of ten states with 90% of reported cases of Lyme disease. The other nine states are Connecticut, Rhode Island, New York, Pennsylvania, Delaware, New Jersey, Massachusetts, and Wisconsin.
Lyme disease is caused by the bacterium Borrelia burgdorferi, which is carried primarily by deer ticks. The young ticks are often no larger than the head of a pin, which can make them nearly impossible to spot. The larger, flat bodied “dog ticks” do not transmit Lyme disease. If a deer tick is attached to your skin for less than 24 hours, your chance of getting Lyme disease is very small.
If an attached tick is discovered, use fine-tipped tweezers to grasp the tick as close to the skin
surface as possible. Pull upward with steady, even pressure. Don’t twist or jerk the tick; this can
cause the mouth parts to break off and remain in the skin. If this happens, remove the mouthparts
with tweezers. If you are unsuccessful in removing the tick, or if mouth parts remain in the
skin, consult a physician. After removing the tick, thoroughly clean the bite area and your hands
with rubbing alcohol, or soap and water. Avoid folklore remedies such as “painting” the tick with
nail polish or petroleum jelly, or using heat to make the tick detach from the skin. Your goal is to
remove the tick as quickly as possible-not waiting for it to detach.
Lyme disease symptoms can be divided into early localized, early disseminated and late
disseminated stages. In the early localized stage (3-30 days post-tick bite) the patient may
experience fatigue, headache, fever, chills, muscle and joint aches and swollen lymph nodes, or
may be completely without symptoms. Some people get a small bump or redness at the site of a
tick bite that goes away in 1-2 days, like a mosquito bite. This is a normal response to irritation
from the tick and does not mean that you have Lyme disease. However, an expanding “bull’s eye
rash called erythema migrans is of concern and may mean you have been exposed to the B.
The erythema migrans rash occurs in approximately 70-80% of infected persons and begins at
the site of a tick bite after a delay of 3-30 days (average is about 7 days). Untreated, the infection
may spread from the site of the bite to other parts of the body, producing an array of symptoms
in the early disseminated stage including:
• Other bull’s eye lesions appearing on other parts of the body.
• Pain and swelling in the large joints (such as in the knees)
• Facial or Bell’s palsy (loss of muscle tone on one or both sides of the face causing a
• Severe headaches and neck stiffness due to meningitis (inflammation of the spinal cord
• Heart palpitations and dizziness due to damage to the conducting system of the heart.
Many of these symptoms will resolve over a period of weeks to months, even without treatment.
However, approximately 60% of patients with untreated infection may progress to the late
disseminated stage and begin to have intermittent bouts of arthritis, with severe joint pain and
swelling. Up to 5% of untreated patients may develop chronic neurological complaints months to
years after infection. These include shooting pains, numbness or tingling in the hands or feet, and
problems with short-term memory.
Patients treated with appropriate antibiotics in the early stages of Lyme disease usually recover
rapidly and completely. Patients with certain neurological or cardiac forms of illness may require
intravenous antibiotic treatment. However, approximately 10-20% of patients will have
symptoms that persist for months to years even after treatment with antibiotics. Also, having had
Lyme disease doesn’t protect against re-infection. This stresses the need for continued tick bite
prevention activities such as wearing appropriate clothing when in tick-infested areas, daily tick
checks, and quick removal of attached ticks.
To prevent Lyme disease and other tick-borne illnesses, the best protection is to avoid contact
with ticks. If you are working in areas that may have ticks you should do the following:
• Wear light colored clothing (spot ticks easier) with long sleeve shirts and pants.
• Tuck your pants into your socks and you shirt into your pants to make it harder for the
tick to reach your skin.
• Use repellents that contain 20% or more DEET on the exposed skin for protection that
lasts up to several hours.
• Use products that contain permethrin on clothing. Treat clothing such as boots, pants, and
socks. It remains protective through several washings. Pre-treated clothing is available
and remains protective for up to 70 washings.
• Check your clothing and skin carefully after being outdoors in likely tick infested areas
and remove ticks promptly
• Inspect any pets daily and remove any ticks found