Tertiary Syphilis

What is Tertiary syphilis?

Tertiary syphilis represents the destructive, late-stage manifestations of an untreated Treponema pallidum infection. These complications typically emerge years after the initial exposure because the spirochete (spiral-shaped bacterium) persists when earlier stages remain unrecognized. Although this stage is now rare where screening and antibiotics are widely available, it remains clinically important because untreated infection can cause irreversible organ damage. Identifying these late-stage sequelae is critical for preventing irreversible organ damage and neurologic decline.

What causes Tertiary syphilis?

The spiral bacterium Treponema pallidum causes the disease by spreading through the bloodstream and seeding the skin, skeletal system, heart, and central nervous system. In the absence of initial therapy, these persistent organisms trigger a delayed-type hypersensitivity, which is a T-cell-driven inflammatory response.

This chronic inflammation eventually damages the vasa vasorum, the small vessels that supply the walls of large arteries, along with the meninges and vital organ parenchyma. Risk factors for developing this advanced stage include untreated early infections, HIV co-infection, and significant barriers to follow-up care within high-risk sexual networks.

What are the signs and symptoms of tertiary syphilis?

Individuals often present with progressive neurologic deficits, gummatous lesions, or significant cardiovascular involvement years to decades after the initial infection. Tabes dorsalis involves dorsal column degeneration in the spinal cord, leading to ataxia (loss of muscle coordination), decreased proprioception, and lancinating pain. Cognitive decline and diffuse cortical dysfunction, known as general paresis, mark advanced central nervous system involvement. Cardiovascular manifestations frequently center on ascending aortitis, which leads to aortic root dilation and aortic regurgitation.

Chronic mucocutaneous nodules called syphilis gummas develop through granulomatous inflammation and can erode underlying bone or ulcerate the skin. Clinicians distinguish these lesions from malignant lesions using the clinical exam, serologic testing, and biopsy when needed.

How is tertiary syphilis diagnosed?

The initial evaluation uses a nontreponemal assay, such as the Rapid Plasma Reagin (RPR), to quantify antibody levels and monitor the future response to treatment. A positive screening result requires confirmation with a treponemal-specific test, such as the FTA-ABS (fluorescent treponemal antibody absorption) or the TP-PA assay.

For suspected tertiary syphilis, clinicians usually perform a lumbar puncture to evaluate for neurosyphilis before treatment. Cerebrospinal fluid testing includes protein levels, cell count, and CSF-VDRL testing. Cardiovascular assessment involves echocardiography or CT angiography to evaluate for an ascending aortic aneurysm when aortitis is suspected.

How is tertiary syphilis treated?

The standard treatment for tertiary syphilis without neurologic involvement is intramuscular benzathine penicillin G, administered as 2.4 million units weekly for three weeks. If neurosyphilis is confirmed or cannot be safely excluded, patients require 18-24 million units of aqueous crystalline penicillin G daily for 10-14 days.

Following therapy, providers monitor serologic titers. Repeat cerebrospinal fluid testing is reserved for patients with persistent or recurrent neurologic symptoms or an inadequate serologic response. Surgical intervention may be necessary to repair aneurysms or severe tissue damage from syphilis gummas, along with antimicrobial therapy.

What are the most important facts to know about Tertiary syphilis?

• Tertiary syphilis causes severe, late-stage organ damage years after an untreated Treponema pallidum infection.
• Persistent infection and immune-mediated inflammation target the vasa vasorum, the meninges, and the skeletal system.
• Hallmark features include syphilis gummas, ascending aortitis, and neurologic degeneration such as Tabes dorsalis or general paresis.
• Diagnosis requires Rapid Plasma Reagin (RPR) screening followed by FTA-ABS or TP-PA confirmation and potential cerebrospinal fluid analysis.
• Effective management uses specific penicillin regimens and long-term serologic follow-up to confirm an adequate response.