What Is Syphilis?

 

I. Introduction 

Syphilis is a sexually transmitted disease that is caused by the spirochete Treponema pallidum.
There are 3 stages of Syphilis: Primary infection ( eg, chancre), Secondary infection(eg, diffuse rash), and Tertiary infection ( eg, symptoms of aortic insufficiency).

II. Microbiology 

T. Pallidum is the causative organism of syphilis and was discovered in 1905. It is a bacterium spirochete. T. Pallidum is a corkscrew-shaped organism with wound spirals.

III. Epidemiology 

From 2000 to 2018, the rise of primary and secondary syphilis cases was primarily increased in men who have sex with men (MSM).MSM was estimated at around 54 percent of all primary and secondary syphilis cases in 2018. There are some risk factors for these such as methamphetamine and having acquired recent sexual partners via social media. The date also stated that the number of women with syphilis has been increasing from 2013 to 2018. Moreover, there also has been an increase in the number of cases of congenital syphilis. There is a high rate that the HIV patients seem to be associated with syphilis and 42 percent of MSM with primary and secondary syphilis have HIV, compared with 8 percent of men who have sex with women and 4 percent of women.

IV. Transmission 

The transmission of T. Pallidum occurs via direct contact with infectious lesions during sex.T.Pallidum can cross the placenta and affect the fetal resulted infection. Sexual transmission can be exposed to the organisms when there is an open lesion with the primary chancre and with secondary syphilis (mucous patches and condyloma lata). These lesions are very contagious with around 30 percent of efficacy. Patients with early latent syphilis can be infectious when there are recent lesions that were missed on the initial evaluation. Syphilis can be spread by kissing or touching a
a person who has active lesions on the lips, oral cavity, breasts, or genitals.
Syphilis is a sexually transmitted disease that can be associated with HIV.

V. Pathophysiology 

Early local infection: T.Pallidum can get access to subcutaneous tissues via microscopic abrasion. The spirochete can be provoked ulcerative lesions by the host’s immune system. The ulcerative lesion is called Chancre.

During this time, some organisms can spread to the regional lymph nodes, with subsequent dissemination.
T.Pallidum stimulates the host defense system (innate and adaptive cellular immune responses to the skin and blood). Humoral immune also respond to T.pallidum and lead to the development of a variety of antibodies that can be detected early in the course of syphilis.
Late infection: A partially immune hypersensitive host may react to the presence of treponemes, generating a chronic inflammatory response.

Gummas or late benign syphilis often attacking skin, viscera, or other tissues( eg, bone, brain, abdominal viscera). It is characterized by the presence of granulomas resulting from consistent with a cellular hypersensitivity reaction.
Cardiovascular disease in syphilis mostly attacks the arch of the aorta and aortic valve due to vasculitis of the vasa vasorum (endarteritis obliterans).

VI. Stages of disease

Syphilis generally is divided into early and late stages.
 Early syphilis: In this stage, we have primary and secondary, which occur within weeks to months after initial infection, as well as early latent syphilis (asymptomatic within 12 months)
 Late Syphilis: the patients who are untreated and progress to late latent disease( asymptomatic) or develop major complications (eg, tertiary syphilis). The duration of the phase may appear at any time from 1 to 30 years after primary infection and can involve a wide variety of different tissues.

Patients can present with central nervous system manifestation (neurosyphilis)at any time during the course of infection.

VII. Clinical findings 

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 Early syphilis : 
 Primary syphilis(chancre) : 
There is a localized skin lesion (chancre) and it can occur around 21 days (range 3 to 90 days). The lesion is papule, painless, and shortly it becomes ulcerate, size around 1 to 2 cm ulcer with a raised, indurated margin. { click here for images }. The lesions can be associated with regional lymphadenopathy often bilateral.
Chancres can heal spontaneously within 3 to 6 weeks in the absence of treatment. 
 Secondary syphilis : 
Weeks to a few months after the chancre develops, 25% of the patients with untreated infection develop a systemic illness. Secondary syphilis can also heal by itself without treatment, except in the case of severe cutaneous ulcerations called lues maligna.

Occasionally, the untreated patients can relapse up to 5 years after their initial episode. 
Secondary syphilis can be presented with a variety of signs and symptoms.
 Generalized symptoms : 
– Constitutional symptoms: Including fever, headache, malaise, anorexia, sore throat, myalgias, and weight loss. It can result from the widespread dissemination of T.Pallidum. 
– Adenopathy: Secondary syphilis has lymph node enlargement with palpable nodes present in the posterior cervical, axillary, inguinal, and femoral regions. The epitrochlear nodes are particularly suggestive of the diagnosis. These nodes are generally minimally tender, firm, and rubbery inconsistency.
 Dermatologic findings : 
–Rash: the rash is a diffuse, symmetric macular or papular eruption involving the entire trunk and extremities, including palms and soles. In patients with HIV, a more severe ulcerative form of secondary syphilis termed ‘ Lues Maligna‘ has been reported.

– Alopecia: It also called “moth-eaten” alopecia. This may be noted on the scalp, eyebrows, or beard, and is usually reversible with treatment.

 Gastrointestinal findings : 
–Hepatitis: syphilitic hepatitis is characterized by high serum alkaline phosphatase levels on laboratory examination. Mild clinical hepatitis resolves with treatment. 
–Gastrointestinal abnormalities:  It may become extensively infiltrated or ulcerated, this can be misdiagnosed as lymphoma. 
 Musculoskeletal abnormalities: Synovitis, osteitis, and periostitis can occur, but resolve after treatment. 
 Renal abnormalities: albuminuria, nephritic syndrome, or acute nephritis with hypertension and acute renal failure. Pathologically, membranous glomerulonephritis, sometimes with crescents, can be seen.
 Neurologic/ocular findings : 
– Headache: Invasion of the cerebrospinal fluid is common in early untreated disease.
– Meninges and vascular manifestations: meningitis, meningovascular disease, or stroke.
– Ocular findings: anterior uveitis, posterior uveitis, or panuveitis, which is often granulomatous. Posterior uveitis typically presents as multifocal chorioretinitis 
 Late syphilis : 
Around 25 to 40 percent of patients with untreated syphilis can develop the late disease. The clinical events may appear at any time from 1 to 30 years after primary infection. 
The most common clinical finding include: 
– Cardiovascular syphilis ( especially aortitis)
– Gummatous syphilis (granulomatous, nodular lesions which are rare, can occur in many organs, usually skin and bones).
– Central nervous system involvement (particularly general paresis and tabes dorsalis).
 Tertiary syphilis: This stage, It is involved the cardiovascular system or gummatous disease (granulomatous disease of the skin and subcutaneous tissues, bones, or viscera).
 Cardiovascular: it involves the ascending thoracic aorta resulting in a dilated aorta and aortic valve regurgitation. It may due to vasculitis in the vasa vasorum leading to a weakening of the wall of the aortic root. Typically, it occurs 15 to 30 years from the initial infection in the untreated patients. Syphilitic aneurysms rarely lead to dissection. 
Chest films often show a calcified ascending arch of the aorta, reflecting the chronic inflammation of the intima. Syphilis may be associated with coronary arteries, resulting in coronary artery narrowing and thrombosis.
 Gummatous syphilis: It is very uncommon. Gumma can occur anywhere, including skin, bones, or internal organs. The lesions have around, irregular, or serpiginous shape. Visceral gummas may present as mass lesions. 
 Central nervous system: It may occur as many as 25 years after the initial infection (eg, general paresis and tabes dorsalis).