Syphilis infection
Summary
Definition
Syphilis is a sexually transmitted infection caused by the spirochaetal bacterium Treponema pallidum, subspecies pallidum. It is found only in human hosts. Infection is typically acquired through direct person-to-person sexual contact with an individual who has early (primary or secondary) syphilis.[1] Most sexual transmission of syphilis probably occurs from direct contact with syphilitic lesions on the genitals or mucous membranes. Transmission from mother to fetus during pregnancy causes congenital infection.[1] Syphilis has often been described as the great imitator because many of the symptoms and signs are difficult to distinguish from other diseases.[2][Figure caption and citation for the preceding image starts]: Electron micrograph of Treponema pallidum on cultures of cotton-tail rabbit epithelium cellsCDC/Dr David Cox; used with permission [Citation ends].
History and exam
Key diagnostic factors
- presence of risk factors
- anogenital ulcer
- lymphadenopathy
- diffuse rash
- constitutional symptoms
- fatigue
- rhinitis (congenital syphilis)
- hepatosplenomegaly (congenital syphilis)
- patchy alopecia
- condylomata lata
- memory impairment, altered mood, confusion, or dementia
- visual changes
- Argyll-Robertson pupils
- loss of sense of vibration, proprioception, and position sense
- ataxia
- loss of anal and bladder sphincter control
- positive Romberg's sign
- diastolic murmur
- rubbery lesions/nodules with a necrotic centre
- miscarriage, stillbirth, or neonatal death (congenital syphilis)
- premature labour and intrauterine growth retardation (congenital syphilis)
- neonatal skin rash (congenital syphilis)
- tibial bowing (congenital syphilis)
- craniofacial malformation (congenital syphilis)
- tooth abnormalities (congenital syphilis)
- necrotising funisitis (congenital syphilis)
Other diagnostic factors
- mouth ulcer
- asymptomatic with positive serology (latent syphilis)
- tremor
- headache
- meningismus
- eye pain
- hearing loss
- seizures
- peripheral oedema
- jaundice
- peripheral neuropathy
- areflexia
- angina
- dyspnoea
- organomegaly
- skin or visceral organ perforation or collapse of structure
- neonatal neurological abnormalities (congenital syphilis)
Risk factors
- sexual contact with an infected person
- men who have sex with men (MSM)
- illicit drug use
- commercial sex workers
- multiple sexual partners
- people with HIV or other STIs
- syphilis during pregnancy (risk for congenital syphilis)
Diagnostic investigations
1st investigations to order
- dark-field microscopy of swab from lesion
- serum treponemal enzyme immunoassay (EIA)
- serum Treponema pallidum particle agglutination (TPPA)
- serum Treponema pallidum haemagglutination (TPHA)
- serum fluorescent treponemal antibody absorption (FTA-ABS) test
- immunocapture assay
- line immunoassay (LIA) serological test
- serum rapid plasma reagin (RPR) test
- serum Venereal Disease Research Laboratory (VDRL) test
Investigations to consider
- lumbar puncture, cerebrospinal fluid (CSF) analysis
- chest x-ray
- echocardiogram
- computed tomography brain
- magnetic resonance imaging brain
- HIV test
- fetal ultrasound scan
- full blood count
- long-bone x-rays
- liver enzymes (aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase) and bilirubin
- auditory brainstem response
- audiometry
- fetal skeletal survey
Emerging tests
- Treponema pallidum polymerase chain reaction (PCR) (sample taken directly from ulcerative lesions)
- point of care (POC) testing with either treponemal or combination treponemal/non-treponemal antibody
Treatment algorithm
adults with suspected early infection or sexual contacts of patients with confirmed infection
adults without neurosyphilis
adults with neurosyphilis
congenital syphilis
Contributors
Authors
Juan C. Salazar, MD, MPH, FAAP
Professor and Chair
Department of Pediatrics
University of Connecticut School of Medicine
Physician in Chief
Connecticut Children’s
Hartford
CT
Disclosures
JCS is the author of references cited in this topic.
Adriana R. Cruz, MD
Research Associate
CIDEIM
Cali
Colombia
Disclosures
ARC declares that she has no conflicting interests.
Acknowledgements
Dr Juan C. Salazar and Dr Adriana R. Cruz would like to gratefully acknowledge Dr Jairo M. Montezuma-Rusca, Nicholas Bennett, Patrick French, and Nooshin Barmania, previous contributors to this topic.
Disclosures
PF is an author of a reference cited in this topic. JMMR, NB, and NB declare that they have no competing interests.
Peer reviewers
Robert A. Larsen, MD
Associate Professor of Medicine
University of Southern California
Keck School of Medicine
Los Angeles
CA
Disclosures
RAL declares that he has no competing interests.
William Rodriguez, MD
Assistant Professor of Medicine
Harvard Medical School
Director of Research
Global Health Delivery Project
Harvard School of Public Health
Boston
MA
Disclosures
WR declares that he has no competing interests.
Jennifer Handforth, MB ChB, MRCPCH, DTM&H
Consultant Paediatrician
Croydon University Hospital
Croydon
UK
Disclosures
JH declares that she has no competing interests.
Differentials
- Genital herpes
- Chancroid
- Primary HIV infection
More DifferentialsGuidelines
- Reducing sexually transmitted infections
- Australian STI management guidelines for use in primary care - syphilis
More GuidelinesPatient leaflets
Syphilis: what is it?
Syphilis: how is it diagnosed and treated?
More Patient leafletsVideos
Diagnostic lumbar puncture in adults: animated demonstration
More videos
Log in or subscribe to access all of BMJ Best Practice
Use of this content is subject to our disclaimer