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Why we still need to talk about syphilis

Why we still need to talk about syphilis

Continuing our series of highlights from Nursing in Practice 365 events, nurse specialist in sexual health Belinda Loftus outlines the history of syphilis, why it remains a significant public health concern and what nurses in primary care need to know about it

The documentation of syphilis dates back centuries. Debate continues over whether the disease was first brought to Europe from Haiti by Christopher Columbus’ crew or introduced by travellers and traders via Africa.

Whatever its origins, likely presentations of syphilis were recorded in the late 1400s and by the 1500s the infection was thought to be endemic in Europe. In 1786, Scottish surgeon Dr John Hunter published a theory that gonorrhoea and syphilis were caused by the same pathogen after inoculating himself with some gonorrhoea pus from a patient. In reality the inoculum was likely contaminated with syphilis which led to him developing symptoms of both conditions.

Around the same time, another Scot Dr Benjamin Bell alternatively proposed that syphilis was a distinct condition, and that gonorrhoea does not progress to syphilis. Then in the 1830s, French physician Philippe Ricord was able to demonstrate that the two diseases were indeed separate, based on more than 2,500 human subjects inoculated by the two infections.

Syphilis – the rise and fall and rise – over the past century

As understanding of syphilis grew, there was optimism that it could be controlled, with one chief of the US Venereal Disease Programme, William J Brown, stating in 1968 that he believed ‘lasting victory over… syphilis, which has plagued human beings for such a long time is inevitable’. Sadly, he has yet to be proved correct, and over 50 years later in 2022 the UK saw the highest numbers of syphilis diagnoses since 1948.

Datasets for syphilis in England are available dating back to 1922. The peak incidence of syphilis coincided with the end of the Second World War, with subsequent levels mapping significant events.

There was a significant increase in the incidence of syphilis after contraception clinics were first allowed to prescribe the contraceptive pill to single women in the 1960s, followed by a significant decrease during the early 80s with the AIDS epidemic and increased public health measures including messaging around safer sex and condom use. Since the 1990s, however, syphilis incidence has been shown a steady upward trajectory (albeit with a slight decrease in 2019).

While the optimism Brown spoke of in overcoming the disease currently remains out of reach, he did also foresee the risks of complacency, noting that ‘significant decreases in reported syphilis lead to a tragic de-emphasis of the control of the disease – only to be followed by its recrudescence’.

For various reasons including structural changes to sexual health services, STI screening, awareness and prevention has lost some ground in recent years, and syphilis cases have increased among people of all sexual orientations. While gay, bisexual, and other men who have sex with men (GBMSM) carry the highest burden, increases have also been seen in those who identify as heterosexual.  Importantly, syphilis spans a much broader age range than other STIs, which tend to be more concentrated in younger age groups.

Detecting syphilis infection

Discovered in 1905, the organism responsible for syphilis is Treponema pallidum. The Treponema genus of bacteria are spirochete (spiral-shaped) organisms that are highly motile under the microscope, moving in a ‘corkscrew’ manner while also bending at the middle, described as ‘jerky jack knife’ motion.

This can be identified under a dark field microscope by specifically trained, experienced staff in a sexual health clinic’s onsite laboratory. The sample for microscopy is a collection of the serous fluid from a presenting ulcer. There is also a commonly available polymerase chain reaction (PCR) test which can detect T pallidum DNA where treponemes are not seen and which may be more reliable if the presenting ulcer is in sites such as the mouth, due to commensal treponemes.

Blood tests for the detection of syphilis antibodies or other immune markers are now the most common method of diagnosis, however. Depending on presenting risk behaviours and any signs and symptoms, this may require repeat samples to be taken to ensure syphilis is excluded.

Syphilis remains tricky to diagnose clinically

The phrase ‘he who knows syphilis knows medicine’ is attributed to Sir William Osler, known as the father of modern medicine, and was made in reference to how complex syphilis is. Reinforcing this complexity, the prominent English surgeon Sir Jonathan Hutchinson concluded from studying syphilis presentations that it was an ‘imitator’ of many diseases and instilled in his medical students to never forget syphilis as a differential diagnosis, something that all clinicians including nurses would probably find helpful today when a patient presents with a mixed or confusing picture.

The British Association of Sexual Health and HIV (BASHH) 2015 syphilis guidelines describe syphilis as a multi-staged, multisystem disease. If untreated syphilis has three main stages: primary stage disease; a secondary stage, which is followed by a latent period; and then tertiary stage disease. All three stages have distinct clinical presentations. Some earlier presentations can go unnoticed, such as a painless ulcer or maculopapular rash which can look similar to more familiar conditions – such as herpes simplex virus in the case of an ulcer – both of which can resolve spontaneously. This can lead the patient (and practitioner) to wrongly assume the complaint has resolved and may result in them going on to develop more serious, systemic conditions. See the BASHH website for further information on presentations at each stage.

Data for syphilis diagnoses in 2023 shows that more people are being diagnosed with late latent disease, which puts a greater burden on the patient for multiple attendances for treatment and concordance with treatment regimes. This underscores how important it is for nurses to contribute to early recognition and support their patients to access early specialist care.

Syphilis is treatable – especially when caught early

Over the centuries there have been various treatments for syphilis, some potentially more harmful than the syphilis itself.  Mercury featured prominently from the late 1400s, sometimes with additions such as sulphur and myrrh and earthworms fried in oil. It was administered in various ways such as being applied as a paste, by oral ingestion or injection.

In 1910 a breakthrough in syphilis treatment was discovered by Dr Paul Ehrlich and his student Sahachiro Hata. The treatment, known as ‘compound 606’, was arsphenamine (an arsenic derivative) and was patented under the name Salvarsan.

It was Sir Alexander Fleming’s discovery of penicillin that had the greatest impact on syphilis, however. By 1948 it was being treated with procaine penicillin (an injectable form of the antibiotic combined with local anaesthetic), and from 1952 with benzathine penicillin.

Unlike gonorrhoea, syphilis hasn’t developed resistance to penicillin, and this remains the first-line treatment for syphilis today. For those with penicillin allergy, and in particular when syphilis has advanced to the later stages, it is sometimes preferable to desensitise the patient to penicillin rather than give them an alternative treatment.

Supporting early intervention and prevention

Discussing sexual health issues in non-specialist settings can be challenging for both professionals and patients.  However, many patients – particularly older (50+) adults – consider their GP practice as the best place for advice.

Nurses working in primary care are well placed to open discussions about sexual health and noticing abnormalities that may be related to syphilis, during routine conversation or examination.

Keep syphilis as a consideration when patients present with some of the key symptoms such as:

  • Single painless ulcer (although ulcers may also be multiple and painful).
  • Balanitis.
  • Widespread rash, usually non-itchy, particularly affecting the palms of the hands and soles of the feet.
  • Lymphadenopathy – can be localised in early syphilis but more widespread in secondary infection.
  • Patchy alopecia – patients may describe as ‘moth eaten’.
  • Mucous patches, both oral and genital.

More complex presentations such as splenomegaly, hepatitis and uveitis may be complications of secondary stage syphilis.

Late (tertiary) disease may present with cardiovascular disease complications, infectious arteritis or cognitive impairment – from mild ‘forgetfulness’ through to severe dementia. Fortunately, these tertiary stages are still not commonly seen, but syphilis testing is suggested on the NICE guidance for dementia diagnosis (April 2024), as part of a differential diagnosis exclusion.

When discussing syphilis as a potential cause of a patient’s symptoms, explain that the test is recommended as this is a treatable infection which we are seeing more often at the moment.  Avoid judgemental language and assumptions. Frame the introduction of the possibility of syphilis around the signs and symptoms, suggesting that they can be related to several things, syphilis being one of them, and you would like to exclude that possibility. Using non-stigmatising language is often a concern for clinicians and the People First Charter provides helpful suggestions – these are specifically related to HIV, but the principles are transferable to other conditions. Sexual health services will take referrals or self-referrals.

It is also important to use opportunities to raise a safer sex conversation, including condom use, pre-exposure prophylaxis (PrEP) for HIV and vaccines for Hepatitis A/B, particularly with those who may be participating in higher risk behaviours, mentioning the prevalence of syphilis – as for many it is considered a problem of the past.

So, in summary: why should we still be talking about syphilis?  Because being aware and taking action on syphilis early is working in the best interests of your patient – this is a treatable infection but it can present in multiple different ways, and can lead to significant complications such as permanent hearing or vision impairment. It also supports public health measures by preventing transmission on to others, including partners and neo-natal transmission.

Belinda Loftus is a registered nurse and cluster manager for integrated sexual health at Spectrum Community Health CIC


Sources and further reading

BASHH. UK national guidelines on the management of syphilis 2015. Available at:

Ison C et al. (2001) Microscopy for Sexually Transmitted Infections. Medical Society for Venereal Disease

Davenport-Hines, R (1990) Sex, Death and Punishment. HarperCollins UK

Gott M et al. “Opening a can of worms”: GP and practice nurse barriers to talking about sexual health and primary care. Family Practice 2004; 21(5):528–36

Hinchliff S et al. I daresay I might find this embarrassing: a general practitioners perspective on discussing sexual health issues with lesbian, and gay patients. Health Soc Care Community 2005;13(4):345-353

Hinchliff S et al. How to support the sexual wellbeing of older patients. BMJ 2023;380:e072388

Klaeson K et al. Sexual health in primary healthcare – a qualitative study of nurses’ experiences. J Clin Nurs 2017;26:1545-54   

NICE CKS. Health topics: Dementia. How should I assess a person with suspected dementia? Last revised 2024

Oriel JD. (1994) The Scars of Venus: A History of Venereology. Springer-Verlag

People First Charter. Available at:

Quetel, C (1992) The History of Syphilis. Johns Hopkins University Press

Hunter I. Syphilis in the illness of John Hunter. J Hist Med Allied Sci 1953; 8(3):249-62

UKHSA. Sexually transmitted infections (STIs): annual data tables. Last updated 2023

US Department of Health Education and Welfare (1968) Syphilis; a synopsis

Catterall RD (1964). Venereology for Nurses. English Universities Press


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