What are the possible complications of syphilis?

The medical term “neurosyphilis” describes damage caused by the syphilis bacteria in the nervous system.

In rare cases, the bacteria already cause nerve-related complications in early stages of the disease. One example is meningitis – with symptoms such as a headache, fever, nausea and a stiff neck. Other examples include paralysis of the face muscles and problems with vision and hearing.

But neurosyphilis mainly refers to the late stage of the disease, when the infection has spread to the brain and spinal cord. Along with the symptoms already mentioned, other symptoms are then typical: Damage to the spinal cord can cause sudden, severe waves of pain, usually in the lower belly and in the legs. The arms and legs might feel numb, and paralysis may occur – in other parts of the body, too. Damage to the brain can cause seizures and dementia, leading to forgetfulness, confusion and mood changes.

Neurosyphilis is usually treated with the same antibiotics used in the early stage of syphilis. But they are used for a longer time.

The risk of neurosyphilis is greater if somebody already has an HIV infection and then also gets syphilis. But this complication is generally rare nowadays.

In the late stage of syphilis, growth-like areas of inflammation may develop on various organs and damage tissue there. Known as gummas, they can sometimes be seen on skin as bumps or open sores. If they develop inside the body, they may attack things like bones, joints or internal organs.

Blood vessels may become inflamed too, causing them to be brittle and less elastic. That can make them wider (aneurysm) – especially the main artery, called the aorta. The risk of the aorta tearing is then higher. If it tears, the resulting internal bleeding is life-threatening.

In pregnant women, the course of the disease is the same as in other people. If a woman's syphilis isn't treated during pregnancy, the unborn child will usually become infected through the umbilical cord – especially if the woman was recently infected. In over a third of all cases, this leads to miscarriage or the child dies at birth.

Infected newborns often don’t have any symptoms at first. In rare cases, complications like serious breathing difficulties might occur right after birth. Congenital ("at birth") syphilis symptoms start showing in the first few months of life. They include:

• A rash, especially on the hands and feet
• Pale skin
• Yellowed skin and whites of the eyes
• Sores, similar to those in adults with syphilis
• A fever and runny nose
• Weakness and difficulty drinking
• Diarrhea or seizures

If the children are already toddlers by the time the symptoms start showing, then the symptoms are usually tooth and bone deformities, vision and hearing problems, and sometimes even deafness.

In Germany and other countries, a syphilis test is routinely offered during pregnancy. It should be done as early as possible. If the mother's infection is treated with antibiotics, that protects the unborn child too. Because of this, congenital syphilis is very rare in Germany nowadays. But if it does occur, the newborn child can also be treated with antibiotics.