The development of syphilis occurs in four stages. The primary stage is the appearance of a painless chancre at the site of infection (often internal) about 10 days to 3 months after contact. There are no other symptoms, and the chancre disappears with or without treatment.
The secondary stage usually begins 3 to 6 weeks after the chancre with a rash over all or part of the body. Active bacteria are present in the sores of the rash. Headache, fever, fatigue, sore throat, patchy hair loss, and enlarged lymph nodes may be present. The signs of the secondary stage will disappear with or without treatment, but may reappear over the next 1 to 2 years.
Untreated syphilis then goes into a noncontagious latent period. Some people will have no more symptoms, but about one third will progress to tertiary syphilis, with widespread damage to the heart, brain, eyes, nervous system, bones, and joints. Late syphilis can result in mental illness, blindness, severe damage to the heart and aorta, and death.
Neurosyphilis, infection of the nervous system, frequently occurs in the early stages in untreated patients. There may be no symptoms, mild headache, or severe consequences such as seizures and stroke. Its treatment and course are complicated by concomitant HIV infection.