A quarter of the people Steere interviewed remembered getting a strange, spreading skin rash (erythema migrans) before experiencing any other symptoms. A European doctor happened to be visiting Yale at the time, and he pointed out that the rash was similar to one frequently encountered in northern Europe and known to be associated with tick bites. Most of the rashes were found somewhere on the torso, suggesting a crawling vector rather than a flying one or a spider, but most patients did not remember being bitten.