Misdiagnosis of flu-like illness with typical, non-bull's eye EM. A 45 year old man was seen for 'flu-like' symptoms and was diagnosed with a viral syndrome. Several days later he presented to one of the authors (JA) for re-evaluation of persistent symptoms. Complete physical exam showed a round, red, non-tender skin lesion over the later aspect of his knee. Serology for Lyme disease was negative on ELISA testing. He was treated with oral doxycycline with prompt resolution of his rash and symptoms.