Syphilis: symptoms and treatments

Syphilis is caused by the spiral-shaped bacterium, Treponema pallidum. Syphilis is usually passed on sexually, although the causative bacteria can also enter through a cut or breaks in the skin and may be passed on orally during kissing. Syphilis can also be passed from mother to baby during pregnancy.

What symptoms will I notice?

Primary syphilis: Within hours of infection, the motile bacteria have entered the blood stream and spread all over the body. Nine to ninety days later (an average of 21 days) a painless, shallow ulcer develops at the initial site of infection, which is typically on the genitals, finger or tongue. Local lymph nodes (glands) may also become painlessly enlarged and feel rubbery.

The primary sore, known as a chancre, is teeming with bacteria and is highly infectious. If left untreated, it heals naturally within one or two months to leave a scar. The disease will then progress to secondary syphilis within six to twelve weeks.

Secondary syphilis: Although secondary syphilis may pass unnoticed, many people develop a mild flu-like illness with headache, fever, loss of appetite and fatigue. A dusky-pink skin rash usually appears, which may involve the palms and soles although it's sometimes fleeting and overlooked. This rash varies in appearance and often mimics other conditions, especially non-specific viral illnesses. Widespread swollen lymph nodes usually appear, too.

Other telltale signs include silvery, 'snail track' ulcers on mucous membranes such as those in the mouth and around the genitals and anus. Hair may fall out in clumps and large, flat wart-like growths (condylomata lata) may appear on the genitals. This secondary stage of the disease can persist for a year or more and those affected are highly infectious, even if they don't develop obvious symptoms.

If left untreated, the clinical features improve and the disease then enters a quiet phase in which the infected person seems to be well, with no obvious symptoms and is no longer infectious. Between three and 40 years later, however, one in three people with untreated, latent syphilis enter a third stage of the disease known as tertiary syphilis.

Tertiary or late syphilis: Characterised by tissue destruction, with the production of tumour-like lesions, known as gummas, which invade skin, bones and soft tissues. The bones, nose, tongue and other parts of the body are 'eaten away as if riddled with worms', but thanks to the discovery of antibiotics and diagnostic blood tests, this is now extremely rare in developed countries.

Tertiary syphilis can also weaken the heart and aorta (the largest artery in the body, which may literally burst from a swelling (known as an aneurysm), or attack the nervous system to produce progressive brain damage (formerly known as general paralysis of the insane). There may also be difficulty walking.

Untreated, advanced tertiary syphilis will eventually prove fatal.