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Primary syphilis in Child
See also in: Anogenital,Oral Mucosal Lesion
Other Resources UpToDate PubMed

Primary syphilis in Child

See also in: Anogenital,Oral Mucosal Lesion
Contributors: David O'Connell MD, Yun Xue MD, Susan Burgin MD, Amy Swerdlin MD, Mary Spencer MD, Carol Berkowitz MD
Other Resources UpToDate PubMed


Syphilis is a sexually transmitted infection (STI) caused by the spirochete bacterium Treponema pallidum. It is characterized by a chronic intermittent clinical course. Treponema pallidum is transmitted person to person via direct contact with a syphilis ulcer during vaginal, anal, or oral sex and may enter through skin or mucous membranes. Hence, the locations for syphilitic ulcers include the vagina, cervix, penis, anus, rectum, lips, hands, and inside of the mouth.

Treponema pallidum can also cross the placenta and infect an unborn child, resulting in early congenital syphilis. See also late congenital syphilis.

In the primary stage of syphilis, a painless ulceration, or chancre, typically appears about 21 days after initial infection, often preceded by a firm, painless papule.
  • In girls, the genital chancre is difficult to observe because of its location in the vagina or on the cervix.
  • In boys, the chancre is easily seen on the frenulum or on the coronal sulcus of the penis but may hide under the foreskin.
The entire genital area is susceptible, including the anus and inside the urethra. Chancres are typically asymptomatic. If secondary erosion or fissuring occurs, they may be painful. Other symptoms may include bloody stool and rectal pain.

Chancres vary in size from a few millimeters to several centimeters. They have an incubation period of 10-90 days (average 21 days). The chancre lasts 3-6 weeks and heals spontaneously. All patients with primary syphilis will go on to develop secondary syphilis if the condition is left untreated. Secondary syphilis usually appears 3-10 weeks after the primary chancre and is characterized by a papulosquamous eruption and mucosal involvement, in some cases. Tertiary syphilis may appear months to years after secondary syphilis resolves and can involve the central nervous system (CNS), heart, bones, and skin.

Ocular screening (eg, slit lamp examination) is advised for patients with suspected or proven syphilis.

Childhood sexual abuse is a problem of epidemic proportions affecting children of all ages and economic and cultural backgrounds. There are few unambiguous diagnostic signs of sexual abuse, and they are present in only a minority of victims. They include objective evidence of characteristic genital trauma and the detection of specific STIs. The presence of semen, sperm, acid phosphatase, a positive serologic test for syphilis or HIV, and a positive culture for gonorrhea are considered absolute evidence of sexual abuse when congenital acquisition of the disease and transfusion-acquired HIV are excluded. Nonsexual transmission of syphilis from an infected parent to a child is rare, and sexual abuse should always be assumed until proven otherwise.

Related topics: ocular syphilis, endemic syphilis


A51.0 – Primary genital syphilis

266127002 – Primary syphilis

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Differential Diagnosis & Pitfalls

All patients with a genital ulcer should have serologic testing for syphilis. Consider the following conditions in the differential diagnosis:

Transmission through sexual abuse:
  • Genital herpes simplex virus – Look for multiple small vesicles on an erythematous base; usually painful.
  • Chancroid (Haemophilus ducreyi) – Multiple nonindurated ulcers with irregular, ragged undermined edges; very painful; yellow exudate commonly present.
  • Lymphogranuloma venereum (Chlamydia trachomatis serovars L1-3) – Ulcers usually not observed but can be small, shallow, and painless; often transient.
  • Granuloma inguinale (Klebsiella granulomatis) – Painless, extensive, and progressive; looks like granulation tissue.
Other infectious diseases:
  • Ecthyma gangrenosum – Ulcers are necrotic and rapidly increase, commonly on extremities and trunk.
  • Amebiasis – Starts as a vesicle that ulcerates; typically painful with undermined edges; can have purulent exudate.
  • Genital trauma – Preceded by known insult; erosions are more geometric and painful.
  • Fixed drug eruption – Red-brown papules or annular plaques that are commonly on the penis; can progress to bullae and erosions mimicking syphilis. Recurrent lesions are always located at the same site.
  • Behçet disease – Associated with recurrent oral ulceration, genital ulceration, and ocular abnormalities.
  • Contact dermatitis – Preceded by exposure to irritant; progression to ulceration would be unusual and indicates severe disease.
  • Calciphylaxis - May rarely present with tender ulceration on genital skin; occurs in patients with renal failure.

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Last Reviewed:08/24/2020
Last Updated:08/18/2021
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Patient Information for Primary syphilis in Child
Contributors: Medical staff writer


Primary syphilis is the name given to the first part of the disease caused by infection with the sexually transmitted bacterium, Treponema pallidum. The disease is divided into 3 parts, and it is important to recognize the first part (which involves the skin) so that you can get treated before the disease progresses to the second and third parts, which affect the brain and cause early death. The classic skin lesion of primary syphilis is a red bump on the genitals that opens into a sore, called a chancre. The sore is typically painless and will heal on its own without treatment, but the disease will still be present, so it is very important to show the sore to your doctor. If treated early, syphilis can be completely cured. Syphilis, like other sexually transmitted diseases, is passed from person to person during oral, vaginal, or anal intercourse. It can also be passed from a mother to a baby during birth. If a baby gets syphilis, he/she often dies.

Who’s At Risk

Syphilis infection can occur in any sexually active person, but it tends to affect young men (15-25 years old) who have sex with other men, sex workers, and people who have sex with sex workers. The disease is more common in the southern states and in urban areas in general.

Signs & Symptoms

Initially, a dusky red, flat spot appears at the site of inoculation and is easily missed. Then, a painless ulcer (chancre) appears 18-21 days after initial infection. Genital sites in females affected are the cervix, vagina, vulva, and clitoris. Cervical and vaginal infections may not be recognized. In men, the chancre is easily seen on the penis. Other sites are limited only by human ingenuity and imagination. Other common sites for syphilis are around the mouth (perioral) and between the buttocks (perianal) areas.

Chancres vary in size from a few millimeters to several centimeters. A chancre is usually painless, solitary, and shallow, with a sharp border and a raised, hard edge. About 70-80% of patients have rubbery, non-tender, swollen lymph nodes, often on only one side of the groin, during the first week of infection.

If untreated, the chancre will remain present for 1-6 weeks. If treated, it heals without scarring in 1-2 weeks.

Self-Care Guidelines

Syphilis, in the primary stage, is highly contagious and can heal without therapy, making it easy to be mistaken for something less serious. If you are sexually active and suspect you have been exposed to syphilis or have an ulcer in the mouth, genital area, or anal area, you should seek medical care immediately. You should avoid any further sexual activity and notify any previous sexual partners.

Syphilis can be prevented by abstaining from casual sexual activity and using condoms correctly during any sexual contact. If you are in a long-term relationship, make sure that you know your partner's sexual history or ask that your partner is tested prior to engaging in sexual activity.

When to Seek Medical Care

See your doctor immediately if you are sexually active or suspect you have been exposed to someone with syphilis. DO NOT attempt self-care if you have any ulcer in the genital, mouth, or anal area. Avoid sexual activity and notify your sexual partner(s) of your illness. Additionally, you should seek medical advice if you have had intimate contact with someone with syphilis, have been using intravenous drugs, or if you have engaged in sex with multiple or unknown partners.


Blood and fluid tests will be done to look for other infectious sexually transmitted diseases, which are often present along with syphilis.

Antibiotics (penicillin, doxycycline, or tetracycline) will be given, and blood tests will be done again; you will be followed for 2 years to be sure the infection is gone.

Do not engage in sexual activity until the chancre is healed and follow-up blood tests have shown that the infection has been cured.


Bolognia, Jean L., ed. Dermatology, pp.1271-1282. New York: Mosby, 2003.

Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine. 6th ed. pp.1263, 2164-2165. New York: McGraw-Hill, 2003.
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Primary syphilis in Child
See also in: Anogenital,Oral Mucosal Lesion
A medical illustration showing key findings of Primary syphilis : Regional lymphadenopathy, Sexually active
Clinical image of Primary syphilis - imageId=865123. Click to open in gallery.  caption: 'A punched out ulcer with a raised border on the glans.'
A punched out ulcer with a raised border on the glans.
Copyright © 2023 VisualDx®. All rights reserved.