Syphilis infection can occur over many decades, producing a range of symptoms. Over the three stages of infection: primary, secondary, and tertiary; syphilis presents different symptoms.
In primary infection, many infections are asymptomatic, and occasionally harmless ulcers may form on the genitals or site of infection.
Secondary syphilis typically involves weight loss, alopecia, and a rash presenting. This occurs in the months following initial infection.
Tertiary syphilis typically involves gumma forming. These are painful growths on bones and other tissue, and cause lots of pain.
When syphilis infection elicits an immune response, sleeper cells are formed. These dormant cells are able to enter immune-privileged tissues, and restart the infection when the immune response decreases.
Syphilis insanity is another manifestation of the disease, giving neurological symptoms.
Treponema pallidum is a spirochete with periplasmic flagella. It also has a very slow growth rate, making it harder for the immune system to detect the infection.