Lyme disease is an infection with Borrelia burgdorferi, a bacteria that is transmitted by tick bite. Not all ticks have the bacteria, so therefore not all tick bites cause Lyme disease. Ticks belonging to the Ixodes species most often transmit the infection (Fig 1). Most infections are diagnosed in the summer as ticks run rampant and outdoor activities are abundant. With prompt recognition and treatment, Lyme disease can be easily cured.
So what do you do if you get a tick bite? Transmission of the bacteria is very low if you remove the tick within the first 24 hours of getting bit. As soon as you recognize the tick, use a pair of tweezers to firmly grasp the insect at the base of the body, very close to the surface of the skin. Pull perpendicularly, straight away from the skin’s surface to remove the entire insect, and avoid leaving the head embedded in the skin. Once you’ve done this, watchful waiting of the area will tell you if you need to see your healthcare provider.
The classic rash associated with Lyme disease is called erythema migrans (Fig 2). It is present in up to 60-90% of people who develop Lyme disease. It starts as a small red bump at the site of the bite and spreads outward over the next several days or weeks. Its appearance may start to resemble a “bull’s-eye”, a manifestation of the spreading bacteria in the skin. Erythema migrans is generally painless, but you may feel fatigued, run a fever or have a headache at this stage. Eventually the rash and the symptoms will fade away, but the bacteria will begin to spread systemically in the body and other symptoms can start months or years later. These can include joint pain and swelling, headaches, nerve sensations, muscle weakness, and heart palpitations or chest pain. There is a blood test that can detect Lyme disease, but it may not show infection within the first 3-6 weeks after the bite. This is why recognizing the rash is so important.
Antibiotics given orally for 2-3 weeks in the early stages of Lyme disease is generally curative. If diagnosed in the later stages, IV antibiotics and hospitalization are required and the disease can be much more difficult to eradicate.
Remember: Not all tick bites transmit Lyme disease. In areas where Lyme disease is endemic (Fig 3), only 1% of tick bites result in Lyme disease. The sooner the tick is removed, the less of the risk of bacteria transmission. If you develop a fever or a rash after a known tick bite or exposure to ticks in a wooded area, make sure to call your healthcare provider to be seen and evaluated.
As with many medical problems, an ounce of prevention is worth a pound of cure. Wear DEET containing insect repellant on exposed skin. If you are going to spend an extended amount of time in a wooded area or tall grass, consider wearing more clothing to cover exposed skin. Clothing can also be pretreated with special washes to repel insects. Treat your outdoor pets with appropriate tick prophylaxis to avoid bringing ticks into your home. Always shower as soon as possible after spending time outdoors and do a good skin check looking for any ticks.
An excellent resource on Lyme disease symptoms and treatment can be found at www.cdc.gov/lyme/.