Symptoms of syphilis are similar in both men and women. During early and more infectious stages, the symptoms are mild and often difficult to recognise.

The symptoms develop in three stages:

• primary syphilis or stage 1
• secondary syphilis or stage 2 followed by the hidden or the latent phase
• tertiary syphilis or stage 3

Primary syphilis

Primary syphilis symptoms may appear any time from 10 days to three months after exposure to the infection. The symptoms are mild and the commonest symptom is appearance of a small, painless sore or ulcer (called a chancre). The sore may appear on the part of body from where the infection has entered. Typically it is seen on the tip of the penis, vagina, anus, rectum, tongue or lips. Most people only have one sore, but some people have more.

In addition, there may be swelling of lymph nodes. The sore will then disappear within two to six weeks and, if the condition is not treated, syphilis will move into its second stage.

Secondary syphilis

This is stage 2 of the infection. This stage appears a few weeks after the disappearance of the sore. Symptoms include a non-itchy skin rash that may appear over the palms of the hands or soles of the feet or anywhere in the body.

In addition, there may be swollen lymph nodes, headaches, fatigue, fever, weight loss, hair loss in patches and pain in the joints. These symptoms also resolve within a few weeks, or come and go over a period of months.

Latent phase

After the secondary phase, the infection moves to a latent or hidden phase. There are no symptoms during this phase. Latent syphilis can still be passed on during the first year of this stage of the condition. This can occur through unprotected sexual contact. However, after a couple of years this condition becomes non-transmissible.

The latent stage can continue for many years (even decades) after the primary stage. Without treatment, there is a risk that latent syphilis will move on to the most dangerous stage 3 or tertiary stage.

Tertiary syphilis

Around a third of people who are not treated for syphilis develop serious symptoms in the tertiary stage. The symptoms depend on the affected organ. Syphilis in this stage may affect:

• brain
• nerves
• eyes
• heart
• bones
• skin
• blood vessels

In the brain it may cause stroke, loss of memory (dementia), psychosis, depression, mania loss of co-ordination, paralysis of limbs and numbness, nerve defects like tabes dorsalis, deafness, blindness, skin rashes and heart disease. Syphilis may cause death at this stage.

Syphilis during Pregnancy

Syphilis during pregnancy can be passed on to the unborn or newly born baby. This may lead to complications like congenital syphilis, still birth and neonatal death.

Congenital Syphilis

Severity ranges from asymptomatic to fatal. There may be:

• spontaneous abortion
• stillbirth
• brain infection (encephalitis)
• generalized skin rash
• runny nose (termed snuffles)
• liver damage
• multiple organ failure
• bleeding disorders
• consumption coagulopathy

These are symptoms seen immediately after birth.

Some features that appear later include:

• inflammation or osteitis of long bones
• dental malformations
• abnormalities of facial bones
• skin changes (keratitis)
• hearing loss
• chronic neuropsychological deficits etc.