The symptoms of syphilis

If the typical early symptoms develop, that usually happens around 2 to 3 weeks after becoming infected. But they may appear a little sooner or only months later. A hard, reddish bump develops where the syphilis bacteria entered the body. Because the disease is mainly passed on during sex, the bump usually forms on the outer genitals – for example, on the penis or the lips of the woman's genitals. If the bacteria were passed on during anal or oral sex, the bump may form around the anus (bottom), the lips or the mouth. In rarer cases, it can also develop in other areas where there was close contact – like on a nipple.

Over the next few days or weeks, the bump gets bigger and turns into a sore known as a chancre (about 0.5 to 1 cm in size). These sores do not hurt in the genital and anal area, but can be painful in the mouth. Some people have several of them. Each sore contains a lot of bacteria that can easily be passed on to others during sex. This kind of sore is the main symptom of the primary (first) stage of syphilis.

The nearby lymph nodes gradually become swollen as well. If the sore is in the genital area, the lymph nodes in the groin are swollen but do not hurt. As a result, some people don’t notice these first signs of syphilis.

The symptoms go away after about 4 to 6 weeks: The sore heals, sometimes leaving a small scar. The lymph nodes shrink back to their normal size.

If any other symptoms occur at all, it can take several weeks or months until they do: You then develop a fever and the lymph nodes become swollen again – but this time in different places, like the armpits. You might also feel tired and have a sore throat, headache or joint pain.

A rash with patches or little bumps develops as well, and sometimes becomes scaly. The rash may appear on the whole body, and it might itch. It is yellowish or reddish-brown, and can be difficult to see in people with darker skin.

The symptoms usually come in waves: They go away on their own and then come back after a while. The rash may be different when it returns. For instance, it may only cause red patches on the palms of the hands and soles of the feet. In later stages, people may also have a sore throat, hair loss, sores in the mouth, and skin discoloration on the throat. Wart-like bumps might grow in the genital area or in skin folds. They join up and form flat, extended areas of skin (known as Condylomata lata) that contain a lot of syphilis bacteria and are very contagious.

The symptoms go away after about two years and don't come back for a long time – often never again. Even if the syphilis is never diagnosed or treated, the bacteria can remain in the body. That may cause late complications many years down the line, including pain, paralysis and confusion.