The hallmark manifestations of tertiary syphilis fall into three categories: gummatous lesions (soft, destructive growths), cardiovascular disease (particularly aortitis and aortic aneurysm), and neurosyphilis (including tabes dorsalis and general paresis). These complications appear 10 to 30 years after the initial infection and, in the pre-antibiotic era, developed in roughly one-third of people who went untreated. Today tertiary syphilis is rare, but recognizing its signs remains critical because the damage it causes is often irreversible.
Gummatous Lesions
Gummas are the most visually distinctive sign of tertiary syphilis. They are soft, tumor-like growths made up of granulomatous tissue, and they can form almost anywhere in the body: skin, bone, liver, and other internal organs. On the skin, a gumma typically appears as a painless, dusky-red to brown nodule or plaque with a central “punched-out” ulcer covered in crusted, necrotic debris. These lesions can grow several centimeters across and are locally destructive, eroding through surrounding tissue.
When gummas target bone, the most commonly affected sites are the long bones, skull (especially the frontal and parietal bones), ribs, sternum, and vertebrae. Bone involvement ranges from surface-level inflammation to full lytic destruction visible on imaging. In one documented case, a gumma eroded through the left frontal bone of the skull; in others, vertebral body destruction caused back pain, leg numbness, and difficulty walking. Bone gummas can also affect the clavicle and sternum, producing chest or bone pain as the first noticeable symptom.
Cardiovascular Syphilis
Cardiovascular involvement is the most life-threatening form of tertiary syphilis. The infection targets the aorta, the body’s largest artery, by inflaming the tiny blood vessels that supply its wall. Over years, this weakens and scars the aortic tissue, producing a characteristic “tree bark” wrinkling of the inner surface that is visible during surgery or autopsy.
The three major cardiac complications break down roughly as follows: thoracic aortic aneurysm (30 to 40% of cardiovascular syphilis cases), aortic valve disease causing the valve to leak (about 30%), and narrowing of the coronary artery openings (10 to 20%). Any of these can be fatal. An aortic aneurysm may slowly expand and erode into nearby structures like the vertebrae, ribs, or sternum. Aortic valve damage can lead to heart failure as the left ventricle enlarges to compensate for the leaking valve. Coronary narrowing can trigger a heart attack. The heart muscle itself is rarely affected directly.
Neurosyphilis: Tabes Dorsalis and General Paresis
Neurosyphilis occurs when the syphilis-causing bacterium invades the central nervous system. It takes several forms in the tertiary stage, with tabes dorsalis and general paresis being the two most recognized.
Tabes dorsalis results from damage to the nerve fibers in the spinal cord that carry sensory information. It produces a characteristic unsteady gait, numbness in the toes and feet, sharp or lightning-like pains in the legs, and loss of bladder control. People with tabes dorsalis often lose their sense of position, making it difficult to walk in the dark or with eyes closed.
General paresis affects the brain itself, causing progressive cognitive decline: confusion, poor concentration, personality changes, irritability, and depression. Without treatment it advances to dementia. Other neurological symptoms across both forms can include seizures, headaches, tremors, muscle weakness, and visual problems up to and including blindness.
The Argyll Robertson Pupil
One of the most specific physical findings in tertiary syphilis is the Argyll Robertson pupil. Both pupils appear abnormally small and irregular. They do not constrict when exposed to bright light, yet they constrict normally when focusing on a nearby object. This split response, called light-near dissociation, develops gradually over months to years, often starting as a sluggish light reaction before the reflex disappears entirely.
The presence of Argyll Robertson pupils is considered highly specific to late-stage syphilis and strongly points to neurosyphilis. It typically appears alongside other tertiary features rather than in isolation.
Eye and Ear Involvement
Tertiary syphilis can also damage the eyes and ears beyond the pupil changes described above. In the eye, it may cause inflammation of the uveal tract (both front and back), inflammation of the retinal blood vessels, corneal inflammation, and optic nerve swelling. Gummas can even form on the eyelids. These problems can threaten vision if not identified.
Hearing loss and balance problems from syphilitic damage to the inner ear, sometimes called otosyphilis, can also occur in late disease. Both ocular and otic syphilis are treated aggressively because the sensory damage can become permanent.
How Tertiary Syphilis Is Confirmed
Diagnosis relies on a combination of clinical signs and blood tests. Two types of blood tests are used together: a screening test that detects general markers of tissue damage, and a confirmatory test that identifies antibodies specific to the syphilis bacterium. Both need to be reactive for a presumptive diagnosis. When neurological symptoms are present, a spinal fluid sample is tested as well. A reactive spinal fluid test in someone with neurological signs and positive blood tests is considered diagnostic of neurosyphilis. Imaging such as CT or MRI helps identify gummas in bone or soft tissue, and echocardiography or CT angiography reveals aortic damage in cardiovascular syphilis.