Lyme Disease: Symptoms, Diagnosis & Treatment

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  • 0:05 Tick-Borne Danger
  • 1:04 Lyme Disease
  • 4:10 Diagnosis
  • 4:57 Treatment
  • 6:26 Lesson Summary
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Lesson Transcript
Instructor: Angela Hartsock

Angela has taught college Microbiology and has a doctoral degree in Microbiology.

Lyme disease has been gaining in prevalence in the United States in recent years. In this lesson, we will explore the disease itself as well as its diagnosis and treatment.

Tick-Borne Danger

Labor Day is fast approaching. It's a great time to pack up the family and head to the Adirondack Mountains for a final farewell to summer. After several hours of driving, you arrive at your cabin and decide to take a nature hike to stretch your legs before unpacking. You, your family, and your dog, Meatball, stroll off into the woods, but before long it opens into a beautiful field. The grass and goldenrod are waist-high, overgrowing the narrow deer trail. Your crew pushes through, brushing your bare legs through the grass. Every now and then you feel a tickle on your thighs, calves, and ankles but it is easily ignored in the glorious expanse of nature.

Later in the evening, you notice that every member of your party brought home hitchhikers: ticks. Those tickles were deer ticks finding a tantalizing blood vessel to settle into for a quick feed. Without worry, you pluck them all off and enjoy the rest of your vacation. Until those sinister bulls-eye-shaped rashes appear. Uh oh.

Lyme Disease

You, your family, and even Meatball, have just developed the first symptom of Lyme disease, an illness caused by the spirochete bacteria Borrelia burgdorferi, acquired by the bite of an infected deer tick, Ixodes scapularis. This bite from an infected tick is required for the development of Lyme disease. You should seek medical treatment, but you are busy and decide to ignore it. What you should expect now is three distinct stages of illness.

The first stage of Lyme disease occurs between 3 and 30 days after the tick bite. At the spot of the bite, a red rash develops and slowly expands, up to 12 inches across. The rash forms a classic bulls-eye shape, distinctive for Lyme disease. Erythema migrans is the name given to the red, bulls-eye shaped rash characteristic of Lyme disease. This rash is rarely itchy or painful, distinguishing it from a mosquito bite, and it appears in about 80% of those infected. In addition to the rash, you have probably developed a fever, swollen lymph nodes, muscle and joint aches, chills, and fatigue as your immune system starts mobilizing to attack the bacteria. This is the best, most effective time to start treatment. But, you didn't.

You're probably feeling pretty down with the initial flu-like symptoms, but things are about to get worse. Several days to several weeks after the rash appears, the bacteria begin spreading throughout your body via the bloodstream. Borrelia burgdorferi is an intracellular pathogen, meaning it can penetrate into your cells. The symptoms that develop now depend on what cells the bacteria invade. More rashes appear as the bacteria invade and destroy skin cells. Borrelia can migrate to your brain and spinal cord causing headaches, neck stiffness, and memory problems. Bacteria in your joints can lead to severely painful and swollen joints and shooting pains. In some cases, Lyme disease can lead to the onset of Bell's palsy, which is a loss of muscle tone in the face. One or both sides of your face can appear droopy, as you can no longer contract the facial muscles. Finally, Borrelia can invade your heart, destroying heart cells and changing your heart rhythm. This can cause heart palpitations and dizziness. I'm sure now you're feeling really sick all the time. By now, you really should have gotten treatment. But again, you didn't. Eventually, you feel better and chalk it all up to a case of the flu.

It has now been months to years after that tick bite on that memorable Labor Day vacation. Since then, you have suffered from occasional bouts of grossly swollen joints, usually your knees, accompanied by severe pain. You have numbness and tingling in your extremities and problems with your memory.

Eventually, you learn that all of these symptoms and their pattern are associated with Lyme disease. You think back to that tick bite and the red rash that followed. By now, you are probably very angry at yourself for not seeking medical attention from the get go. Maybe you could have avoided all this agony.


So, let's go back in time and do things a little differently. At the first appearance of the initial flu-like symptoms and bulls-eye rash, you went to your doctor. For the 80% of people that develop the classic bulls-eye rash, diagnosis of Lyme disease is a snap. Diagnosis is based on the appearance of the bulls-eye rash and a recent exposure to ticks. For the unfortunate 20% without the rash, diagnosis can be a bit trickier. Usually a patient has to test positive for Borrelia antibodies in two different blood tests. Testing negative in either test usually suggests that it is not Lyme disease. Unfortunately, false positive and false negative tests are common. This can lead to misdiagnosis, delayed treatment, and further development of symptoms.

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