Category Archives: Syphilis

Syphilis is a sexually transmitted disease caused by the bacterium Treponema pallidum subspecies pallidum. It has been called “The Great Pretender”, as symptoms can resemble other diseases. If syphilis is untreated, it can cause serious health complications. There are distinct stages of a syphilis infection, known as primary, secondary, latent, and tertiary.

What symptoms can occur in secondary syphilis?

• Skin rashes of varying appearance (usually the first sign of secondary infection)
• Sores in the mouth, vagina, or anus
• Large, raised, gray, or white lesions in warm, moist areas (e.g., mouth, armpits, groin)
• Fever
• Swollen lymph glands
• Sore throat
• Patchy hair loss
• Headaches
• Weight loss
• Muscle aches
• Fatigue

Not everyone who has secondary syphilis will develop all of these symptoms, but skin rashes usually occur, although sometimes they may be so faint that they are unnoticed. The symptoms of secondary syphilis eventually disappear whether or not treatment is received. Untreated cases will progress to the tertiary stage, and possibly the potentially fatal tertiary stage. Treatment cures syphilis and prevents the progression of the disease (1).

How long does syphilis take to progress to the secondary stage?
On average, it takes 21 days after exposure before an infected individual shows the first symptom of syphilis, which is one or more chancres (in the primary stage). However, some people may notice a chancre just 10 days after they become infected, while it can take up to 90 days for other people. The chancres of a primary infection typically last 3–6 weeks before they disappear (whether or not treatment is received) (1).

Some people develop symptoms of a secondary infection while the primary chancre is healing (1), but more typically the secondary stage doesn’t begin until 2–8 weeks after the chancre has disappeared (2).

 How can I prevent secondary syphilis?
A single dose of Benzathine penicillin G 2.4 administered intramuscularly is effective to treat and cure anyone with a primary infection to prevent it from progressing to the secondary stage. This treatment is also effective in the secondary and early latent stages, but three doses are required for the late latent stage (1).

The correct use of latex condoms does reduce the risk of syphilis, but only when the infected area (e.g., chancre) or site of potential exposure is covered (1).

How can I get tested for syphilis?
Lab testing from a simple, self-collected finger-prick blood sample can accurately diagnose a syphilis infection. There are two types of lab tests–nontreponemal and treponemal, which are both required for an accurate diagnosis. We offer a treponemal assay, which detects antibodies specific to syphilis, but these antibodies usually remain detectable for life even after successful treatment; hence this assay identifies both current and past (resolved) infections (3).

References:
1. Syphilis – CDC Fact Sheet (Detailed). (2017, January).
2. Tudor ME, et al. (Updated October 2021). Syphilis. StatPearls [Internet].
3. Henao-Martinez AF & Johnson SC. (2014). Diagnostic tests for syphilis. Neurol Clin Pract. 4 (2), 114-122.

Related Tests

• Complete STD Panel
• Treponema pallidum (Syphilis) Antibody Screen

What is syphilis?
Syphilis is a sexually transmitted disease, which has been called “The Great Pretender”, as symptoms can resemble other diseases. Syphilis is primarily transmitted during sexual contact, or during pregnancy or childbirth from an infected mother to her infant (1).

What causes syphilis?
Syphilis is caused by infection with the bacterium Treponema pallidum subspecies pallidum.

What are the symptoms of syphilis?
Untreated syphilis infections have four distinct stages.

Primary syphilis is characterized by a skin lesion, called a chancre, which appears 10-90 days after infection. It can be a single chancre or multiple chancres may form (1). Chancres last 3-6 weeks and health whether or not treatment is received. If untreated, the infection progresses to the secondary stage (2).

Skin rashes and/or lesions in the mouth, vagina, or anus occur during the secondary stage of infection. Additional symptoms in the secondary stage can include fever, sore throat, hair loss, weight loss, swollen lymph glands, headaches, muscle aches, and fatigue (1). Like the primary symptoms, secondary symptoms will also disappear whether or not treatment is received. However, the syphilis infection will progress to the latent stage if adequate treatment does not occur (2).

The latent stage is not associated with any symptoms, except the syphilis-causing bacterium is still present. During the early latent stage, transmission can still occur. The latent stage can last for many years, with 15-40% of untreated individuals developing tertiary syphilis (3).

In some cases, the latent stage progresses to a potentially fatal tertiary stage. This can occur 10-30 years or more after acquiring a syphilis infection. Multiple different organ systems can be affected including the brain, nerves, eyes, heart, liver, bones, and joints.

Who is at risk of syphilis?
The primary high-risk populations for syphilis are men who have sex with men, and HIV-positive individuals. Other high-risk populations include individuals who have been incarcerated, sex workers, and members of certain racial groups (4).

How is syphilis diagnosed?
Syphilis diagnosis is by two types of laboratory analyses of a blood sample – nontreponemal and treponemal tests. Both are required for an accurate diagnosis.

How is syphilis treated?
Primary, secondary, and early latent stage syphilis (infection within 2 years) is treated with a single intramuscular dose of Benzathine penicillin G. Late latent stage syphilis (more than 2 years after original infection) requires three intramuscular doses of Benzathine penicillin G at weekly intervals (5).

References:
1. Kent ME & Romanelli F (2008). Reexamining syphilis: an update on epidemiology, clinical manifestations, and management. Ann Pharma, 42 (2), 226-236.
2. Syphilis – CDC Fact Sheet (Detailed). (2017, January).
3. Peeling RW, et al. (2017). Syphilis. Nat Rev Dis Primers, 3(17073).
4. Schwenk TL (2016, June 9). Screening High-Risk Populations for Syphilis. NEJM Journal Watch.
5. Workowski KA & Bolan GA (2015) Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR Recomm Rep, 64 (RR-03), 1-137.

Related Tests

• Complete STD Panel
• Treponema pallidum (Syphilis) Antibody Screen

Syphilis is a sexually transmitted disease caused by the bacterium Treponema pallidum subspecies pallidum. It has been called “The Great Pretender”, as symptoms can resemble other diseases. If syphilis is untreated it can cause serious health complications. There are distinct stages of a syphilis infection, known as primary, secondary, latent, and tertiary.

Primary stage
A skin lesion, called a chancre, is the first sign of a syphilis infection. Chancres appear at the location where syphilis entered the body anytime from 10-90 days after infection, with an average onset of 21 days post-infection (1). Chancres last for three to six weeks and heal whether or not treatment is received. Individuals in this stage are very infectious. If untreated, the infection progresses to the secondary stage (2).

Secondary stage
Skin rashes and/or lesions in the mouth, vagina, or anus occur during the secondary stage of infection. These may appear when the primary chancre is healing or several weeks after it has healed. Additional symptoms in the secondary stage can include fever, sore throat, hair loss, weight loss, swollen lymph glands, headaches, muscle aches, and fatigue. Individuals in this stage are infectious. Like the primary symptoms, secondary symptoms will also disappear whether or not treatment is received. However, the syphilis infection will progress to the latent stage if adequate treatment does not occur (2).

Latent stage
There are no visible signs or symptoms of syphilis during the latent (hidden) stage. However, syphilis-causing bacteria (T. pallidum) are still present. The latent stage can last for many years, with 15-40% of untreated individuals developing tertiary syphilis (3). Individuals in the early latent stage (less than 1-2 years after the original infection) may be infectious, but individuals in the late latent stage are generally not infectious.

Tertiary stage
In rare cases, the latent stage progresses to a potentially fatal tertiary stage. This can occur 10-30 years or more after acquiring a syphilis infection. Multiple different organ systems can be affected including the brain, nerves, eyes, heart, liver, bones, and joints. The associated symptoms vary depending on the affected body parts. Individuals with tertiary syphilis are not infectious (1).

Gummatous syphilis or later benign syphilis can occur in the tertiary stage. It is characterized by soft, tumor-like balls of inflammation, which typically affect the skin, bone, and liver. Cardiovascular syphilis is a relatively common complication of tertiary syphilis, where the heart tissue is affected (1).

Neurosyphilis and ocular syphilis
At any stage of infection, T. pallidum can invade the nervous system causing neurosyphilis, or the eyes causing ocular syphilis. Neurosyphilis symptoms can include headaches, paralysis, dementia, sensory deficits, and altered behavior. Ocular syphilis can cause vision changes, decreased visual acuity, and blindness (2). 

Congenital syphilis
Syphilis during pregnancy is associated with miscarriage, stillbirth, or infant death shortly after delivery in up to 40% of cases. Congenital syphilis occurs when an infected pregnant woman passes syphilis to her baby during pregnancy. If an infected infant is not treated immediately, serious health complications can occur, including enlargement of the liver and spleen, rashes, fever, neurosyphilis, lung inflammation (4), developmental delays, seizures, and other fatal complications (5).

References
1. Kent ME & Romanelli F (2008). Reexamining syphilis: an update on epidemiology, clinical manifestations, and management. Ann Pharmacother, 42 (2), 226-236.
2. Syphilis – CDC Fact Sheet (Detailed). (2017, January).
3. Peeling RW, et al. (2017). Syphilis. Nat Rev Dis Primers, 3 (17073).
4. Woods CR. (2009). Congenital syphilis-persisting pestilence. Pediatr Infect Dis J , 28 (6), 536-537.
5. Sexually Transmitted Diseases Treatment Guidelines, 2015. (2015). MMWR, 64 (RR-3).

Related Tests

• Treponema pallidum (Syphilis) Antibody Screen
• Complete STD Panel

Syphilis a sexually transmitted disease caused by the bacterium Treponema pallidum subspecies pallidum. It is primarily transmitted during sexual contact or during pregnancy from an infected mother to her infant. It has been called “The Great Pretender”, as symptoms can resemble other diseases. If syphilis is untreated it can cause serious health complications.

Penicillin G is the preferred drug for treating individuals in all stages of syphilis. Although treatment cures the disease and prevents disease progression, it does not repair any tissue damage that has already occurred, and does not prevent reinfection at a later date (1). There is currently no effective vaccine available for syphilis (2).

Treatments in the primary and secondary stages
The primary stage of syphilis is generally characterized by the appearance of one or more skin lesions (chancres) at the location where syphilis entered the body. This can appear anytime from 10-90 days after infection, with an average onset of 21 days post-infection. Skin rashes mark the secondary stage of syphilis, which may appear as the primary chancre is healing or several weeks later (3).

Individuals with either primary or secondary stage syphilis are treated with a single intramuscular dose of Benzathine penicillin G. Adults receive 2.4 million units, while infants and children receive 50,000 units/kg (up to 2.4 million units). These individuals should also be tested for HIV, and retested in three months in areas with a high prevalence of HIV. Clinical and serologic evaluations should be conducted at six and twelve months after treatment (1).

Treatments during the latent and tertiary stages
There are no visible signs or symptoms of syphilis during the latent (hidden) stage. However, syphilis-causing bacteria (Treponema pallidum subspecies pallidum) are still present. In the early latent phase (less than one to two years after original infection), transmission can still occur as up to 25% of individuals can develop a recurrent secondary infection (4). In rare cases, the latent stage progresses to a potentially fatal tertiary stage. This can occur 10-30 years or more after acquiring a syphilis infection.

The recommended treatment in the early latent stage is the same as for the primary and secondary stages – a single intramuscular dose of Benzathine penicillin G. Individuals with late latent syphilis, or latent syphilis of unknown duration, or tertiary stage syphilis should be treated with three intramuscular doses of Benzathine penicillin G at one-week intervals. Adults receive 2.4 million units per dose, while infants and children receive 50,000 units/kg per dose (up to 2.4 million units per dose) (1).

Treatments during pregnancy
Penicillin G is the only known effective treatment for preventing the transmission of syphilis from an infected pregnant mother to her baby. The penicillin dosage depends on the stage of syphilis and pregnancy. Any infected woman with a penicillin allergy should be desensitized and treated as normal with penicillin, as there are no proven alternative treatments for syphilis during pregnancy (1).

Treatments for neurosyphilis and ocular syphilis
At any stage of infection, Treponema pallidum subspecies pallidum can invade the nervous system causing neurosyphilis, or the eyes causing ocular syphilis. The recommended regimen for individuals with these complications is with Acqueous crystalline penicillin G for 10-14 days. This can be administered as 3-4 million IV units every four hours, or by continuous infusion (1).

Treatment complications
The Jarisch-Herxheimer reaction is a complication that can occur within the first 24 hours of any syphilis treatment. When penicillin kills the harmful syphilis-causing bacteria, toxic bacterial products are released. Some individuals develop a systemic inflammatory reaction to these toxins in the bloodstream, resulting in symptoms including fever, chills, rigor, hypotension, headaches, muscle pain, hyperventilation, and anxiety (5). This reaction is more common in individuals with early syphilis. It may also induce early labor or cause fetal distress in pregnant women (1).

References
1. 2015 STD Treatment Guidelines Syphilis. CDC. (2015, June 4). 
2. Sexually Transmitted Diseases Treatment Guidelines, 2015. (2015). MMWR, 64 (RR-3).
3. Kent ME & Romanelli F (2008). Reexamining syphilis: an update on epidemiology, clinical manifestations, and management. Ann Pharmacother, 42 (2), 226-236.
4. O’Byrne P & MacPherson P (2019). Syphilis. BMJ, 365 (4159).
5. Belum GR, et al. (2013). The Jarisch-Herxheimer reaction: revisited. Travel Med Infect Dis, 11 (4), 231-237.

Related Tests

• Treponema pallidum (Syphilis) Antibody Screen
• Complete STD Panel

Syphilis a sexually transmitted disease caused by the bacterium Treponema pallidum subspecies pallidum. It has been called “The Great Pretender”, as symptoms can resemble other diseases.

Syphilis during pregnancy is associated with miscarriage, stillbirth, or infant death shortly after delivery in up to 40% of cases (1). Congenital syphilis occurs when an infected pregnant woman passes syphilis to her fetus during pregnancy. The transmission of syphilis to the infant is more likely to occur in situations where the mother has been infected during the pregnancy, but many cases still occur where the mother was infected prior to the pregnancy (2). There is about a 70% chance of an untreated woman passing syphilis to her fetus (3).

Early congenital syphilis
The signs of early congenital syphilis are usually apparent at 3-14 weeks of age, but in rare cases, there may be no obvious symptoms until 2-5 years of age. A wide range of symptoms are associated with early congenital syphilis including:

• Inflammation of the umbilical cord, iris of the eye, and bone joints
• Fever
• Skin rash and shedding of the skin on the palms and soles
• Low birth weight
• Anemia
• High cholesterol levels at birth
• Meningitis
• Jaundice
• Mental retardation
• Hair loss
• Pneumonia
• Enlarged liver and spleen

Late congenital syphilis
The signs of late congenital syphilis appear after five years of age, but may not be diagnosed until adulthood. A wide range of symptoms are associated with late congenital syphilis including:

• Bone pain
• Retinitis pigmentosa (serious eye disease)
• Peg-shaped upper central incisors
• Interstitial keratitis (blurred vision, eye pain, light sensitivity)
• Bone abnormalities (prominent forehead, saddle nose, short upper jaw)
• Fissuring around the mouth and anus

Diagnosis
Congenital syphilis should be suspected in any child of a mother with syphilis, as there is a 70% chance of transmission in untreated pregnant women (3). However, the wide range of symptoms associated with congenital syphilis often leads to a delayed diagnosis. Furthermore, maternal antibodies to syphilis transferred through the placenta to the fetus can complicate the interpretation of diagnostic tests (4).

Factors that influence newborn treatment decisions include:

• Diagnosis of syphilis in the mother
• Syphilis treatment of the mother
• Presence of clinical, laboratory, or radiographic evidence of syphilis in the newborn
• Comparisons of maternal and newborn antibody titres

Prevention and treatment
The prevention of congenital syphilis is by far the best option. This is by routine syphilis testing in pregnant women and prompt treatment to prevent the transmission to the fetus. If an infected pregnant woman is untreated there is a 70% risk of passing syphilis to her fetus.

For infected infants, treatment must begin immediately to prevent developmental delays, seizures, and other fatal complications (5). Penicillin is the most effective treatment for infants with congenital syphilis. Additional treatments may include corticosteroids and atropine drops (2).

References
1. Syphilis – CDC Fact Sheet (Detailed). (2017, January). 
2. Congenital Syphilis. (2009). Rare Disease Database. 
3. Sheffield JS, et al. (2002). Congenital syphilis after maternal treatment for syphilis during pregnancy. Am J Obstet Gynecol, 186 (3), 569-573.
4. 2015 STD Treatment Guidelines – Congenital Syphilis. (2015, June 4). CDC. 
5. Sexually Transmitted Diseases Treatment Guidelines, 2015. (2015). MMWR, 64 (RR-3).

Related Tests

• Treponema pallidum (Syphilis) Antibody Screen
• Complete STD Panel