Which of the following is false concerning spirochetes? The primary lesion (similar in appearance to a fever blister) of syphilis is called the chancre. They are all transmitted by direct contact. They also cause Lyme disease, infectious jaundice, and relapsing fever. Secondary syphilis is characterized by a maculopapular rash. Tertiary syphilis includes dementia, aortic aneurysms, and gummas.