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Skip Navigation LinksPennsylvania Department of Health > My Health > Environmental Health > Health Tracking Program > Lyme Disease



Lyme disease is spread through the bite of infected blacklegged ticks, more commonly called deer ticks. It is caused by the bacterium Borrelia burgdorferi which is primarily found in ticks in the northeastern and northern parts of the country. The risk of being bitten exists in all seasons except when the temperature is below freezing. In 2015, 95 percent of the confirmed cases were reported from Connecticut, Delaware, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Virginia and Wisconsin. According to the Centers for Disease Control and Prevention, Pennsylvania leads the nation in the number of confirmed Lyme disease cases with 7,351 confirmed cases in 2015 alone.  Lyme disease is a reportable disease in Pennsylvania.   
Lyme disease map 
Symptoms of LYme disease —Three Stages
Tick bites are categorized into three stages: early, late and untreated. 
The early stage refers to symptoms that develop 3 to 30 days after the tick bite.  These include fever, chills, headache, fatigue, swollen lymph nodes, and muscle and joint aches. There is also a rash known as erythema migrans (EM) which is another early stage symptom and shows in about 75 percent of infected people. This rash begins at the site of the bite after a delay of 3 to 30 days, average being 7 days. It expands gradually reaching up to 12 inches or more, is warm to the touch, can result in a bullseye appearance and can appear anywhere on the body. 
Late stage symptoms can occur anywhere from days to months after a tick bite.  These symptoms can include:
  • severe headaches and neck stiffness
  • additional EM rashes on other areas of the body 
  • arthritis with severe joint pain and swelling
  • facial palsy
  • intermittent pain in tendons, muscles, joints and bones 
  • heart palpitations or an irregular heartbeat 
  • episodes of dizziness or shortness of breath
  • inflammation of the brain and spinal cord
  • nerve pain
  • shooting pains, numbness or tingling in the hands or feet
  • problems with short-term memory
Untreated Lyme disease which is the last stage can include symptoms from both the early and late stage categories. If you live in an area that is known for ticks, or recently traveled to an area known for ticks, and you start to experience any of the symptoms listed, seek immediate medical attention.
A diagnosis of Lyme disease is based on symptoms and whether or not a person was in an area known to have blacklegged ticks.
Most people are treated for two to four weeks with antibiotics and recover quickly.  Some patients have lingering symptoms of fatigue, pain or joint and muscle aches after they finish treatment. There are a few cases, referred to as chronic Lyme disease or Post-treatment Lyme disease where symptoms can last up to 6 months.
  • occurs most frequently in children five to 14 years of age or adults 40 to 50 years of age
  • recreational and occupational exposure to ticks and outdoor activities
  • having skin exposed while in wooded or grassy areas--ticks attach easily to bare skin
  • not removing ticks promptly or properly can cause bacteria from a tick bite to enter your bloodstream
         If you remove a tick within two days, your risk of acquiring Lyme disease is low. 

  • use a product with 20 percent DEET or higher on both skin and clothing
  • wear light-colored clothing so you’ll have a better chance of seeing the ticks 
  • wear long pants, and tuck them into your socks
  • outfit yourself in bug repellent apparel
  • stay on the trail
  • avoid tick-infested places
  • be vigilant and do a daily tick check
  • put your clothes in the dryer and tumble them on high heat which kills the ticks
  • check your pets and your kids before letting them loose in the house
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