From Volume 43, Issue 3, April 2016 | Pages 267-271
Syphilis is on the increase globally. While recognized more frequently in patients with, HIV/AIDS, it is not unusual among immune competent individuals sometimes presenting with unusual manifestations and/or behaviour. This paper reviews the history and clinical features of syphilis and draws attention to the oral manifestations.
Pox, a disease characterized by multiple pustules, is a term that includes chickenpox, smallpox and syphilis – the great pox or grande verole. Luetic disease is another term. Syphilis is a sexually shared infection (SSIs) or transmitted disease (STD), formerly termed a venereal disease (VD). A person can be infected with more than one SSI, and SSIs generally increase the liability to transmission of viruses such as HIV, especially if there is mucosal or cutaneous ulceration. Younger people (age 16–24 years) account for half of all SSI cases, and the incidence of virtually all is increasing globally. In the UK in 2008, nearly half a million people attended clinics for SSIs.
Now recognized as infection with the bacterium Treponema pallidum and known for centuries, a syphilis epidemic broke out among the soldiers of Charles VIII of France. In 1495 he invaded Naples, and by the end of that year syphilis had spread throughout France, Switzerland and Germany, reaching Britain in 1497 and, by 1500, had reached Scandinavia, Hungary, Greece, Poland and Russia.1 Europeans transported it to Calcutta in 1498 and, by 1520, syphilis had reached Africa, the near East, China, Japan and Oceania. Before the days of political correctness, the English and Italians called syphilis the ‘French disease’, the ‘Gallic disease’, ‘morbus Gallicus’, or the ‘French pox’; the Germans called it ‘French evil’; the Scottish called it ‘grandgore‘; the Russians called it the ‘Polish disease’; the Polish and the Persians called it the ‘Turkish disease’; the Turkish called it the ‘Christian disease’; the Tahitians called it the ‘British disease’; in India it was called the ‘Portuguese disease’, and in Japan syphilis was called the ‘Chinese pox’.1,2
Syphilis rates and trends vary by population subgroup. The risk of syphilis is highest in sex workers. Recently there has been a rapid rise in the number of syphilis diagnoses.3
Large increases in syphilis have been seen among men who have sex with men (MSM). In the USA, rates of primary and secondary (P&S) syphilis among MSM are high (228.8 per 100,000 in 2013), but P&S syphilis in women is far less common (0.9 per 100,000 in 2013). Congenital syphilis trends closely follow P&S trends among women. Rates of P&S are disproportionately increased among US black and Hispanic MSM (compared with white MSM), and among young MSM.4
Ongoing high levels of unsafe sexual behaviour probably contribute to the rise, although rises can partly be attributed to increased testing.3 Syphilis is seen worldwide, increasingly in MSM as already mentioned, and is also present in some migrants.5,6
In migrants, there can be a considerable burden of infectious disease which varies significantly by geographic region and reflects global epidemiologic patterns. Syphilis may be present along with HIV, hepatitis B and C, or parasitic disease.7,8,9
Syphilis is transmitted from person to person by direct contact with syphilitic lesions and can be transmitted via vaginal, anal, or oral sexual contact. The average time between infection with syphilis and appearance of the first symptom is 21 days, but it can range from 10 to 90 days. Outbreaks among heterosexuals can be halted by condom use, intensive screening, treatment and partner notification. Routine screening among MSM can prevent tertiary syphilis but, despite interventions, infection rates among MSM continue to rise and will soon approach those last seen in 1982 (estimate: 340.7 per 100,000). Infected pregnant women can pass it to their foetus; control of syphilis among women is important to prevent congenital syphilis.10 Vaccination is discussed below.
Treponema pallidum causes a chancre (primary or Hunterian chancre), typically on the glans penis or vulva, occasionally on the lips, tongue or elsewhere. Untreated chancres heal in 3–8 weeks, but are highly infectious and are associated with enlarged, painless, regional lymph nodes. If the infected person does not receive adequate treatment the infection progresses to the secondary stage.
Oral lesions may be seen. More than 60% of reported primary and secondary syphilis cases with oral lesions are among MSM, and 20–70% have HIV.
Syphilis is a great mimic; ulcers (59%), mucous patches (23%), keratosis (6%), pseudomembranes (3%) and gumma (9%) can be seen.11 Features may often be non-specific, with malaise, weight loss, fever, headache, rash (characteristically symmetrically distributed coppery maculopapules on the palms and soles), patchy hair loss, and generalized painless lymph node enlargement with unusual enlargement of epitrochlear nodes. Skin rashes (and/or sores in the mouth, vagina, or anus) are common. Oral lesions are seen in only about one-third of patients and include: painless ulcers (mucous patches and snailtrack ulcers), split papules, condyloma lata and gummas12 (Figure 1). Large, raised, grey or white lesions (condylomas) may develop in the mouth, axilla or groin. The mucosal lesions are infectious. In HIV, syphilis can be atypical and severe (lues maligna; as discussed below). Without treatment, syphilis will progress to the latent and possibly late stages.
The latent (hidden) stage begins when primary and secondary symptoms of syphilis disappear. It can last for years but, although the person remains infected, he/she may exhibit no signs or symptoms.
Features include difficulty co-ordinating muscle movements, paralysis, numbness, gradual blindness and dementia. A main feature is a localized non-infectious granuloma varying in size from a pinhead to several centimetres (gumma), which breaks down to form a deep punched-out ulcer. Skin gummas heal with depressed shiny scars (tissue-paper scars). Bone gummas may affect the long bones (especially the tibia – ‘sabre tibia’) or skull, producing lytic lesions and periostitis with new bone formation. Gummas in the oral cavity may destroy bone, particularly the palate, or involve the tongue. The other main oral manifestation is leukoplakia, particularly of the tongue dorsum, with a high potential for malignant change.
In addition to mucosal or skin lesions, tertiary syphilis may damage the nervous or cardiovascular systems and bones, as well as the foetus. It damages the brain, nerves, eyes, heart, blood vessels, liver, bones and joints and can result in death.
Neurosyphilis, sometimes with sensorineural deafness, also affects about 10% of patients. Meningovascular neurosyphilis has highly variable early symptoms but late effects may be hydrocephalus or lesions of the second, third and eighth cranial nerves, and the pupils are also unequal and unresponsive to light (Argyll Robertson pupils). Paretic neurosyphilis begins insidiously with subtle mental disturbance going on to severe personality changes, complete dementia and widespread paralyses (general paresis of the insane; GPI). Tabes dorsalis (locomotor ataxia) is characterized by atrophy of lumbar posterior nerve roots and sometimes the optic nerves, and can feature sudden attacks of lightning-like pain and paresthesia of leg or trunk, with loss of normal pain sensation and of deep proprioceptive reflexes. The latter cause a tabetic gait in which the feet are slapped on the ground as a result of loss of sense of their position, and the neuropathic joints then become disorganized (Charcot joints). Neurosyphilis is a rare cause of atypical trigeminal neuralgia.
Cardiovascular syphilis (aortitis, coronary arterial stenosis or aortic aneurysms) affects about 10% of patients, typically as a late complication.
Diagnosis of primary syphilis was traditionally by examination of lesional exudates using dark field microscopy (DFM) which allows direct observation of the moving spirochaetes, plus serology. In oral lesions, the DFM diagnosis can be confused by oral commensal treponemes, so specific fluoresceinated antibodies should be used. A negative DFM test does not rule out syphilis. Biopsy may be suggestive of the disease, and diagnostic if specific antibodies are used. Serology is indicated but often negative at this early stage. Non-specific (reaginic) serological tests, useful for screening, include the Venereal Disease Research Laboratory (VDRL), Rapid Plasma Reagin (RPR) card test, Automated Reagin Test (ART) and Toluidine Red Unheated Serum Test (TRUST). RPR is a screening test similar to the VDRL test. Treponema pallidum Polymerase Chain Reaction (Tp-PCR) aids early diagnosis since it may be reactive before conventional serological tests are.13 The diagnostic accuracy of Tp-PCR is greater than that for DFM,14 so Tp-PCR testing is now recommended for the diagnosis of primary or secondary syphilis.15
Specific serological tests, such as Fluorescent Treponemal Antibody Absorbed (FTA-Abs) test, T. pallidum Haemagglutination Test (TPHA) and the Treponema pallidum Immobilization (TPI) tests overcome the problem of false-positive VDRL results, but cannot differentiate syphilis from other treponematoses. The FTA-Abs is probably best reserved for specimens giving discrepant results. Specific tests become positive during primary syphilis and remain positive through untreated secondary or tertiary syphilis but, in contrast to VDRL, remain positive even in treated syphilis. Treponemal Enzyme Immunoassays (EIAs) are an appropriate alternative but another treponemal assay, such as the TPHA, should be used for confirmation.
Primary syphilis is treated with procaine penicillin, benzathine penicillin, doxycycline or erythromycin, but ceftriaxone and azithromycin are also effective. Treatment for secondary syphilis is as for primary syphilis; treatment of tertiary syphilis is procaine penicillin, and lifelong follow-up.
Given concerns about the potential for increased risk for treatment failure, patients with HIV and pregnant women are of particular concern.16,17
HIV-positive people may present different clinical manifestations of syphilis. Syphilis associated with HIV infection may take an atypical, accelerated course with rapid progression to the tertiary stage (lues maligna).18,19 Gummas may develop while the secondary stage is still active.20,21
There may also be higher rates of asymptomatic neurological involvement, atypical and unpredictable antibody responses, slower serological responses to treatment and higher serological failures than in HIV-negative individuals. VDRL in HIV-infected patients with secondary syphilis often responds more slowly to conventional penicillin therapy.22 Factors which appear to affect the likelihood of developing neurological disease include a CD4+ count of 1:32, late-latent disease or lack of response to standard antibiotic treatment.23
Relapse is common, despite treatment, or the response to penicillin may be poor, but the management is the same regardless of HIV status, with early syphilis treated with a single dose of benzathine penicillin intramuscularly.
A pregnant woman with syphilis can, after the fifth month, pass the infection to her foetus with resultant low birth weight, premature delivery or stillbirth. An infected baby may be born without features of disease but, if not treated immediately, may develop serious problems within a few weeks (such as cataracts, deafness or seizures), and can die. Congenital syphilis may cause learning disability and blindness, and typically results in frontal bossing, a saddle nose and Hutchinson's teeth – screwdriver-shaped incisors. Affected children are highly infectious until about 2 years of age; in sub-Saharan Africa congenital syphilis is still a significant public health problem and antenatal screening is important.24
Protection against syphilis infection has been achieved in animal models using an immunization regimen of γ-irradiated T pallidum, demonstrating the future feasibility of a syphilis vaccine.25
Syphilis is a great mimic and should be in the differential diagnosis of oral ulcers or unusual lesions since it is being seen in the UK as elsewhere.26,27
