In the classic form, it evolves from a macule to a papule and finally to an erosion or ulcer. Occasionally, multiple lesions may be present (~40%), with multiple lesions being more common when coinfected with HIV. Lesions may be painful or tender (30%), and they may occur in places other than the genitals (2–7%). The most common location in women is the cervix (44%), the penis in heterosexual men (99%), and anally and rectally in men who have sex with men (34%). Lymph node enlargement frequently (80%) occurs around the area of infection, occurring seven to 10 days after chancre formation. The lesion may persist for three to six weeks if left untreated. Secondary
Secondary syphilis occurs approximately four to ten weeks after the primary infection. While secondary disease is known for the many different ways it can manifest, symptoms most commonly involve the skin, mucous membranes, and lymph nodes. There may be a symmetrical, reddish-pink, non-itchy rash on the trunk and extremities, including the palms and soles. The rash may become maculopapular or pustular. It may form flat, broad, whitish, wart-like lesions on mucous membranes, known as condyloma latum. All of these lesions harbor bacteria and are infectious. Other symptoms may include fever, sore throat, malaise, weight loss, hair loss, and headache. Rare manifestations include liver inflammation, kidney disease, joint inflammation, periostitis, inflammation of the optic nerve, uveitis, and interstitial keratitis. The acute symptoms usually resolve after three to six weeks; about 25% of people may present with a recurrence of secondary symptoms.
Whereas the purpose of this study was to observe the natural history of untreated syphilis; the African-American men in the study were told they were receiving free treatment for "bad blood" from the United States government.The Public Health Service started working on this study in 1932 in collaboration with Tuskegee University, a historically black college in Alabama. Researchers enrolled 600 poor, African-American sharecroppers from Macon County, Alabama in the study. Of these men, 399 had contracted syphilis before the study began, and 201 did not have the disease. Medical care, hot meals and free burial insurance were given to those who participated. The men were told that the study would last six months, but in the end it continued for 40 years. After funding for treatment was lost, the study was continued without informing the men that they were only being studied and would not be treated. Facing insufficient participation, the Macon County Health Department nevertheless wrote to subjects to offer them a "last chance" to get a special "treatment", which was not a treatment at all, but a spinal tap administered exclusively for diagnostic purposes. None of the men infected were ever told that they had the disease, and none were treated with penicillin even after the antibiotic had been proven to successfully treat syphilis.