Syphilis

Syphilis (Latin: syphilis, lues) is a chronic systemic sexually transmitted infection caused by the bacterium Treponema pallidum. The disease follows a staged and relapsing course and affects virtually every organ and system: primarily skin, mucous membranes, nervous, cardiovascular and musculoskeletal systems.

The primary mode of transmission is sexual contact, classifying syphilis among sexually transmitted infections (STI). It can also be vertically transmitted from mother to fetus (congenital syphilis), and, extremely rarely, through blood or household contact. Without treatment syphilis leads to severe, disabling and life-threatening complications.

Aetiology and Pathophysiology

Treponema pallidum enters the human body through tiny defects of the skin or mucous membranes. It multiplies at the site of entry and then spreads rapidly through the lymphatic and blood vessels throughout the body, long before the first clinical symptoms appear.

The underlying pathology is characterized by the systemic damage to small vessels (endarteritis, periarteritis) and the formation of the specific inflammatory infiltrates. The disease course is typically cyclic with active phases alternating with latent ones.

Clinical Significance (Stages of Syphilis)

Several consecutive stages are distinguished in the clinical course of syphilis.

• Primary syphilis:
  • Develops following an incubation period (approximately 3-4 weeks).
  • It is marked by the appearance of a chancre — a painless ulcer with a solid base — at the site of treponema penetration.
  • It is also accompanied by an enlargement of the nearest (regional) lymph nodes (regional scleradenitis).
• Secondary syphilis:
  • Develops 2-3 months after infection if untreated.
  • It is characterized by widespread and polymorphic non-itchy rash on skin and mucous membrane (roseola, papules).
  • Such lesions are highly contagious. This stage follows an alternating course of relapses and latent periods.
• Tertiary syphilis:
  • Develops in some untreated patients several years (typically 3-10 and more) after infection.
  • It causes destructive, irreversible damage. Nodules called gummas are formed. When they decay it leads to the destruction of organs and tissues (bones, skin, liver).
  • Severe manifestations include neurosyphilis (tabes dorsalis, general paralysis) and cardiovascular syphilis (mesaortitis).

Diagnosis and treatment

Diagnosis is based on clinical picture, direct detection of Treponema pallidum in lesion exudate (via dark-field microscopy), and, primarily, on blood serological testing. Non-treponemal tests (RPR) are used for screening and monitoring treatment response, while treponemal tests (ELISA, TPHA) are used to confirm diagnosis.

Penicilin-based antibiotics remain the gold standard for syphilis treatment at all stages. The dosing and treatment duration depend on the stage of the disease. Timely and adequate treatment results in full recovery and prevents progression to late-stage severe complications.