Infectious agent: Borrelia burgdorferi
Description of illness: The most common sign of Lyme disease is a circular rash called an erythema migrans (bull's eye rash), usually occurring within 3 to 30 days at the site of the tick bite. Other common symptoms include fatigue, chills, fever, headaches, muscle and joint aches, nausea, vomiting, conjunctivitis, and swollen lymph nodes. Neurologic symptoms can also occur, including facial weakness, headaches, and radicular pain. In the later stages patients may experience paresthesia, pain due to peripheral neuropathy, and personality, cognitive, and sleep disturbances. Irregular heart rhythms and pain and swelling in large joints may also occur.