Syphilis (the pox, lues) is a sexually transmitted infection.


Syphilis (the pox, lues) is a sexually transmitted infection. The symptoms are very diverse and sometimes only appear many years later. Among others, a painless sore in the genital area or mouth is typical. The infection is treated with antibiotics. The safer sex rules provide good protection against infection.


Syphilis has four stages.

First and second stages

  • Painless, hard sore (chancre) in the genital area or mouth
    • Heals on its own within a few weeks
  • Fever, headache and painful limbs
  • Swollen lymph nodes
  • Fatigue
  • Skin rash (including on the palms of the hands and soles of the feet)
  • Weeping blisters, in particular in skin folds

Third stage

Can last for months or years, often there are no initial symptoms. During progression:

  • Inflammation of the blood vessels
  • Formation of “gummas” (lumps under the skin that contain gummy pus)

Fourth stage

  • Stroke
  • Damage to the spinal cord (mainly affects abdomen and legs)
    • Sensory disorders
    • Disturbance of balance
    • Pain attacks
  • Meningitis
  • Memory disorders and personality changes
  • Paralysis in arms / legs
  • Gait abnormalities
  • Pupil abnormalities (“Argyll Robertson pupils”)

Causes and treatment

Syphilis is caused by the Treponema pallidum bacterium. It is transmitted by bodily fluids:

  • during intercourse (sperm, vaginal secretion)
  • during birth (because the mother is infected)
  • by direct contact with infected blood

Further treatment by your doctor / in hospital

Possible tests
  • Blood test (search for antibodies)
  • Swabs: fluid in blisters, pus, cerebrospinal fluid
Possible therapies
  • Antibiotics

What can I do myself?

Apply the safer sex rules to prevent a syphilis infection:

  • Always use a condom or femidom during sexual intercourse
  • Don't get sperm or blood (including menstrual blood) in your mouth, and don’t swallow

When to see a doctor?

  • Itching, burning or discharge in the genital region
  • After having high-risk (in particular unprotected) sex
    • In particular when fever or other signs of illness appear
  • If your sexual partner is known or diagnosed to have a sexually transmitted infection or disease

Further information

Federal Office of Public Health (FOPH)

Swiss AIDS Federation (AIDS-Hilfe Schweiz)


lues, the pox

Exclusion of liability

CSS offers no guarantee for the accuracy and completeness of the information. The information published is no substitute for professional advice from a doctor or pharmacist.