Patient Articles

Lyme Disease

By: Ken Miller, MD, Danbury, CT

Lyme Disease is an infection caused by a spirochete bacteria (Borrelia burgdorferi) transmitted by a deer tick bite.  When the deer tick attaches to a person, the infection may occur.  The duration of attachment of the tick (> 48 hours) increases the likelihood of getting the infection.  It has been reported in 48 states (not in Hawaii or Alaska), but is most common in the Northeast, Mid-Atlantic, Northern California, and north central USA.

Lyme disease may present with many symptoms including rash, fever, joint pain and swelling, blood inflammation, and neurologic disease.

Early Lyme disease occurs from late spring until the fall.  The rash of Lyme disease occurs 3-30 days following a tick bite.  It is a red, expanding rash and is usually larger than 2.5 inches in diameter.  It is often warm and may be painful, burn, or itch.  Sometimes, it will appear as a bull’s eye.  Since the ticks are often attached to moist areas, the rash will often be found in the groin, trunk, armpit, neck, scalp, and behind the knee.  Only 60% of patients with Lyme disease will recall having a rash.  Flu-like symptoms are often seen in early Lyme disease and include fever, headache, fatigue, and neck muscle and joint soreness.  Oral antibiotics (doxycycline and amoxicillin) are almost always curative in early Lyme disease.

Untreated, some patients who are infected over several weeks or months will develop additional symptoms including: severe fatigue, headache, neck stiffness, irregular heartbeat, paralysis of the face, and nerve pain.  Months after the infection, untreated patients may develop pain and swelling in a few joints, most commonly the knee.  Late neurologic disorders also occur at this time and may present with cognitive problems, pain, and numbness of the extremities.  Treatment of these later symptoms of Lyme disease at this stage may require intravenous antibiotics (Rocephin or cephtriaxone).

Avoiding Tick Bite 

  • Avoid exposure to wooded brush and grassy places including forest and stone walls.
  • Wear long pants and shirts, tucked pant legs, and socks.
  • Wear light colored clothing so it is easier to spot the ticks.
  • Spray insect repellent with DEET on the skin (except the face).
  • Treat clothing with permethrin, which kills ticks on contact.
  • Inspect yourself and children for ticks after outdoor exposure.
  • Lawns treated with anti-tick products (e.g., Sevin) may be helpful.
  • Remove bird feeders and cut the grass closely.

Remove an imbedded tick by grasping the tick as close to the skin as possible with a tweezer.  Wipe the area near the bite with antiseptic ointment after removal.  A localized reaction to the tick bite may have a small, usually less than quarter-size, rash.  Usually, this will go away in one to two days, but observe the area for larger rash for the next 30 days, and seek medical attention if this is noted.

Treatment of asymptomatic tick bites is controversial.  However, it may be advised to treat people who have removed blood engorged ticks, which have likely fed and are more likely to transmit disease.  Also, ticks that may have been embedded for more than 24 hours may justify prophylactic antibiotics.  Doxycycline 200 mg given as one dose may decrease the risk of Lyme disease in these patients by 90%.

Laboratory testing for Lyme disease is usually not indicated when the typical rash is noted by a physician.  Testing for the Lyme disease antibodies is usually a 2 step process.  A screening elisa assay is performed and if positive a confirmatory western blot test is performed for confirmation.  At the onset of early lyme symptoms the test can be negative in 50% of patients but should be positive in almost all patients within 30 days after the onset of symptoms. Unfortunately this test will often remain positive for many years and cannot be used to assess response to treatment.

Treatment of early lyme disease is almost always effective with oral doxycycline or amoxicillin for 2-3 weeks which is 95% effective in curing the infection.  Patients with arthritis, carditis and neurologic lyme may require longer treatment with oral or intravenous antibiotics.

Lyme disease is almost always curable when treated with appropriate antibiotics.  Unfortunately, in some patients with flu symptoms and other systemic symptoms, the joint pains and fatigue may respond more slowly.  Treatment of these symptoms with prolonged antibiotics usually does not lead to more rapid improvement, and most patients will improve over several weeks to months.