A 29-year-old woman presented with knee and elbow pain of 12 days' duration. Twelve weeks earlier in mid-June she had been working in a craft center at a camp on the Chesapeake Bay, Md, but spent much recreational time biking through wooded and open coastland. She recalled scratching a slightly pruritic area on her See also p 1364. lower thigh in early July. Several days later she noticed a circular area of intense redness, approximately 8 cm in diameter, which she attributed to irritation from scratching. Over the next 10 days, the rash grew considerably larger, showing a red outer border more visible than the center. The rash then disappeared gradually. In late July, she felt unusually hot and fatigued, experienced headache and intermittent nausea for 5 days, and had difficulty sleeping and concentrating both at work and while biking. For about 36 hours she had mild pain.
JAMA. 1992 Mar 11;267(10):1381-3