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Lyme disease is an infectious illness named for Lyme, Connecticut, where the first US outbreak occurred. Lyme disease is caused by the bacterium
Borrelia burgdorferi, which is transmitted to humans by the bite of infected black-legged ticks. Different species of the tick can be found on most
continents. In the US, the black-legged tick, known as the deer or bear tick, is particularly common in northeastern and upper Midwestern states. A
different species of the black-legged tick is responsible for transmitting Lyme on the west coast.
Symptoms
Acute (early) Lyme disease symptoms:
* rash - This rash, called erythema migrans (EM), is usually oval or circular, uniform in color and
centered on the initial bite site. Although the “bull’s eye” rash is the classic Lyme disease rash,
it occurs in only 10-20% of the patients who have a rash during their illness. One third of
all Lyme disease patients never have an EM rash.
* fever
* malaise
* fatigue
* headache
* muscle and joint aches
The incubation period from tick bite to the onset of symptoms is usually 1-2 weeks but it can be as long as one month. It is possible for an infected
person to have no symptoms or display only one or two symptoms; this can make obtaining a correct diagnosis difficult.
Persistent (late) Lyme disease symptoms:
* fatigue
* muscle and joint aches
* Bell’s palsy
* pain
* numbness, tingling or burning sensations
* meningitis
* tremor, muscle twitches
* short-term memory loss
* depression, anxiety, panic attacks
* hallucinations
and many others.
The symptoms of late Lyme disease can appear months to years from infection. Left untreated, Lyme disease can cause chronic disability, but it is rarely
fatal. Cases of persistent infection have been known to linger for 20 years before being correctly diagnosed.
Diagnosis
The most reliable method for diagnosing Lyme disease is a thorough medical history and physical exam. The history includes details about
possible tick exposure, current medical problems and a complete review of all symptoms. The physical exam includes a good general exam plus detailed
dermatologic, neurologic and joint exams.
The laboratory tests used to assist in the diagnosis of Lyme disease include the ELISA and Western blots. The ELISA is called the “screening test”; if it is
positive then Western blots are done. Unfortunately, neither is a reliable indicator of illness; test results vary between labs and within the same lab and
false positives and false negatives are common. A 2003 study by CDC researchers demonstrated that the C6 ELISA, a commonly used test for Lyme
disease, performed well for patients with arthritis but missed patients with acute disease and many with early or late neurologic Lyme disease. Because of
these sorts of testing problems, Lyme disease must be diagnosed on clinical grounds. Lab tests may confirm a clinical diagnosis but by
themselves they cannot rule the disease in or out.
Treatment
The treatment of Lyme disease requires the use of antibiotics.
In cases where an EM rash is present, treatment should begin immediately. Blood tests are not recommended because they are often falsely negative.
Most studies on the treatment of early Lyme disease used at least 20 days of antibiotic therapy. Treatment is usually successful; overall cure rates for
this stage are roughly 90%.
Late Lyme disease is much more difficult to treat and while most patients improve with antibiotic therapy, cure rates are much lower. The duration of
treatment can be quite long; some patients
may need to be on antibiotics for months or even years. Others may require intermittent courses of antibiotics. Each case is unique and care need to be
individualized.
Prevention
Lyme disease can be prevented by avoiding areas where ticks thrive. This includes heavily
wooded areas, places with thick underbrush and long grassy areas at the edge of a wood.
When these places cannot be avoided, prevention can be achieved by:
* applying Insect repellents, especially those containing DEET, to exposed skin
* pre-treating clothing, before it is worn, with Permethrin, a tick insecticide
* wearing light-colored clothing so ticks can be easily spotted and removed
* wearing long sleeves and pants; with pant bottoms tucked into the tops of ones socks.
Additionally, ticks usually need to be attached to the skin for at least 24 hours before Borrelia burgdorferi (the Lyme disease bacteria) can be
transmitted. Performing body-wide tick checks after being in tick habitats and immediately removing any discovered ticks may prevent infection.
Upon returning home, go to a designated area, remove clothing to wash and dry as soon as possible.
Bath each day you have been in grassy or wooded areas, remembering to scrub hard to remove any ticks that have not yet attached.
Borrelia burgdorferi, which is transmitted to humans by the bite of infected black-legged ticks. Different species of the tick can be found on most
continents. In the US, the black-legged tick, known as the deer or bear tick, is particularly common in northeastern and upper Midwestern states. A
different species of the black-legged tick is responsible for transmitting Lyme on the west coast.
Symptoms
Acute (early) Lyme disease symptoms:
* rash - This rash, called erythema migrans (EM), is usually oval or circular, uniform in color and
centered on the initial bite site. Although the “bull’s eye” rash is the classic Lyme disease rash,
it occurs in only 10-20% of the patients who have a rash during their illness. One third of
all Lyme disease patients never have an EM rash.
* fever
* malaise
* fatigue
* headache
* muscle and joint aches
The incubation period from tick bite to the onset of symptoms is usually 1-2 weeks but it can be as long as one month. It is possible for an infected
person to have no symptoms or display only one or two symptoms; this can make obtaining a correct diagnosis difficult.
Persistent (late) Lyme disease symptoms:
* fatigue
* muscle and joint aches
* Bell’s palsy
* pain
* numbness, tingling or burning sensations
* meningitis
* tremor, muscle twitches
* short-term memory loss
* depression, anxiety, panic attacks
* hallucinations
and many others.
The symptoms of late Lyme disease can appear months to years from infection. Left untreated, Lyme disease can cause chronic disability, but it is rarely
fatal. Cases of persistent infection have been known to linger for 20 years before being correctly diagnosed.
Diagnosis
The most reliable method for diagnosing Lyme disease is a thorough medical history and physical exam. The history includes details about
possible tick exposure, current medical problems and a complete review of all symptoms. The physical exam includes a good general exam plus detailed
dermatologic, neurologic and joint exams.
The laboratory tests used to assist in the diagnosis of Lyme disease include the ELISA and Western blots. The ELISA is called the “screening test”; if it is
positive then Western blots are done. Unfortunately, neither is a reliable indicator of illness; test results vary between labs and within the same lab and
false positives and false negatives are common. A 2003 study by CDC researchers demonstrated that the C6 ELISA, a commonly used test for Lyme
disease, performed well for patients with arthritis but missed patients with acute disease and many with early or late neurologic Lyme disease. Because of
these sorts of testing problems, Lyme disease must be diagnosed on clinical grounds. Lab tests may confirm a clinical diagnosis but by
themselves they cannot rule the disease in or out.
Treatment
The treatment of Lyme disease requires the use of antibiotics.
In cases where an EM rash is present, treatment should begin immediately. Blood tests are not recommended because they are often falsely negative.
Most studies on the treatment of early Lyme disease used at least 20 days of antibiotic therapy. Treatment is usually successful; overall cure rates for
this stage are roughly 90%.
Late Lyme disease is much more difficult to treat and while most patients improve with antibiotic therapy, cure rates are much lower. The duration of
treatment can be quite long; some patients
may need to be on antibiotics for months or even years. Others may require intermittent courses of antibiotics. Each case is unique and care need to be
individualized.
Prevention
Lyme disease can be prevented by avoiding areas where ticks thrive. This includes heavily
wooded areas, places with thick underbrush and long grassy areas at the edge of a wood.
When these places cannot be avoided, prevention can be achieved by:
* applying Insect repellents, especially those containing DEET, to exposed skin
* pre-treating clothing, before it is worn, with Permethrin, a tick insecticide
* wearing light-colored clothing so ticks can be easily spotted and removed
* wearing long sleeves and pants; with pant bottoms tucked into the tops of ones socks.
Additionally, ticks usually need to be attached to the skin for at least 24 hours before Borrelia burgdorferi (the Lyme disease bacteria) can be
transmitted. Performing body-wide tick checks after being in tick habitats and immediately removing any discovered ticks may prevent infection.
Upon returning home, go to a designated area, remove clothing to wash and dry as soon as possible.
Bath each day you have been in grassy or wooded areas, remembering to scrub hard to remove any ticks that have not yet attached.
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