What is Lyme disease?
Lyme disease is caused by a bacteria, Borrelia burgdorferi. The disease was first recognized in 1975 when large numbers of children were diagnosed with juvenile rheumatoid arthritis in Lyme, Connecticut, and two neighboring towns. Further research showed that bites from deer ticks infected with the bacterium were responsible for the outbreak of arthritis. Ordinary "wood ticks" and "dog ticks" do not carry the infection.
In the U.S., the Centers for Disease Control and Prevention estimates there are about 300,000 cases per year, even though the number reported is much lower.
What are the symptoms of Lyme disease?
Lyme disease may evolve through several phases or stages which can overlap causing symptoms that may involve the skin, joints, heart or nervous system.
Early Lyme disease typically causes a reddish rash or skin lesion known as erythema migrans (EM). The rash starts as a small red spot at the site of the tick bite 1 to 4 weeks after the bite. It expands over a period of days or weeks, forming a circular, triangular, or oval-shaped rash. The rash may look like a bull’s eye because it appears as a red ring that surrounds a clear center area.The rash can range in size from that of a dime to the entire width of a person's back. As infection spreads, several rashes (EM lesions) can appear at different sites on the body.
If the infection goes untreated, you may develop multiple areas of rash, paralysis of facial muscles (Bell’s palsy), heart block (interruption of the electrical system of the heart) or areas of numbness or abnormal sensation (neuropathy).
Untreated late Lyme disease, which occurs months to a year after the initial infection, is most commonly associated with recurring episodes of swollen joints (arthritis) typically of large joints such as the knee. Additionally some patients may develop difficulty concentrating, which is called “brain fog” (encephalopathy).