• Small, painless sore (called a chancre) at the site of infection

• Usually appears 3 weeks after exposure and heals on its own

Secondary Stage:

• Skin rashes (often on palms and soles)

• Mucous membrane lesions

• Fever, swollen lymph nodes, sore throat, patchy hair loss

Latent Stage:

• No visible symptoms, but the infection remains in the body

Tertiary Stage (if untreated):

• Can occur years later

• Damage to heart, brain, nerves, eyes, and other organs

1500s–1600s – Spread Across the Globe:

As European exploration and colonization expanded, syphilis spread worldwide. Some historians believe syphilis may have originated in the New World and was brought back to Europe by Columbus’s crew. Others argue it existed in Europe earlier but wasn’t recognized as a separate disease.

1800s – Mercury Treatments: Mercury was one of the earliest treatments, often applied as ointments or taken orally. It was toxic and caused serious side effects.

1905 – Pathogen Discovered: German scientists Fritz Schaudinn and Erich Hoffmann discovered the bacterium Treponema pallidum, the cause of syphilis.

1906 – First Diagnostic Test: August von Wassermann developed the first blood test to detect syphilis.

1930s–1940s – Tuskegee Syphilis Study: A tragic and unethical U.S. study conducted on Black men in Alabama, where treatment was withheld so researchers could observe the natural course of the disease. It lasted from 1932 to 1972, even after penicillin became the standard treatment. This led to major reforms in medical ethics and research practices.

1943 – Penicillin Revolution: Penicillin was discovered as an effective cure for syphilis, changing treatment dramatically and saving millions of lives.

Today – Resurgence: Despite being curable, syphilis has been on the rise again since the early 2000s, particularly among certain populations and due to reduced STI screening and awareness.