All stages of syphilis are contagious except for the tertiary phase. The tertiary stage of syphilis usually occurs when it is not treated during the first three phases. Syphilis is classified by four stages: primary, secondary, latent, and tertiary.
The time to reach the tertiary phase varies from 5-15 years after acquiring the organism, Treponema. The tertiary phase itself is subdivided into three different forms which include:
- Gummatous syphilis where the body develops soft ulcerated lesions, mostly in the liver. These soft growths can also occur on the skin, bone, heart, lungs, and brain. The lesions can lead to many adverse effects like changes in behavior, leaky heart valves, and bone pain. The syphilitic gummas are not found in all patients with tertiary syphilis.
- Late neurosyphilis is a common feature of tertiary syphilis and is diagnosed through testing of a sample of brain fluid. The symptoms may range from loss of muscle movement, changes in behavior, headache, psychosis, seizures, difficulty with vision and walking, bladder incontinence, and inability to sense vibration. Without treatment, this phase could be fatal in some patients.
- Cardiovascular syphilis also develops in the tertiary phase but is only seen 10-30 years after the initial infection. In this condition, the organism invades the large blood vessels and initiates inflammation known as syphilitic aortitis. This results in bulging of the aorta (aneurysms) which, if not treated, could rupture and cause immediate death.
Tertiary syphilis is not very common. This is because most patients are treated for syphilis early on in the course of the disease. However, it is important to understand that once tertiary syphilis has developed, it is not possible to reverse the tissue damage, as all the changes that occur are permanent.