Man With Ulcer on His Penis

March 2, 2006

A 44-year-old homeless man complains of a “sore” onhis penis. The ulcer developed from a macular lesionon the glans penis about 5 days earlier. The painless ulcerhas not responded to a topical antibiotic ointment he receivedat another clinic.

A 44-year-old homeless man complains of a "sore" onhis penis. The ulcer developed from a macular lesionon the glans penis about 5 days earlier. The painless ulcerhas not responded to a topical antibiotic ointment he receivedat another clinic.He denies any history of trauma, fever, rash, or jointproblems. He had acute bronchitis a month ago and wasgiven tetracycline.He smokes a pack of cigarettes a day and drinks 2or 3 beers daily, but he does not take illicit drugs. He issexually active; his last contact was with a prostitute about3 weeks earlier.This man is poorly nourished but not in distress.Pulse rate is 80 beats per minute and regular; respirationrate, 24 breaths per minute; blood pressure, 110/60 mmHg. He is afebrile; hydration status is good. Dentitionis poor. Small, shotty, rubbery, discrete inguinal glandsare palpable. No periurethral discharge is noted.A well-demarcated circular ulcer with serous dischargeis present on the glans penis. The margin is elevated, andthe base is smooth and firm.The remainder of the examination is normal.You order a darkfield microscopic examination of theserous discharge.What does the slide suggest is wrong-and to whatdiagnosis does the clinical picture point?A. Antibiotic (tetracycline)-induced ulcer
B. Herpetic lesion
C. Syphilitic chancre
D. Penile cancer
E. Lymphogranuloma venereumThe slide shows a typicalspirochete, Treponema pallidum. Inconjunction with this finding, thepatient's history of sexual contactwith a prostitute; the painless,well-demarcated ulcer with a firmbase; and the shotty, rubbery inguinaladenopathy strongly suggestprimary syphilis, C.Hemoglobin level is 11.2 g/dL;white blood cell count, 7200/µL,with normal differential; plateletcount, 200,000/µL. Urinalysis resultsare normal. HIV testing is negative.The VDRL test is positive. Thefluorescent treponemal antibody absorption (FTA-ABS)test is also positive.He is given benzathine penicillin, 2.4 million unitsIM. Unfortunately, the patient is lost to follow-up.A CASE IN POINTDifferential diagnosis. Genital ulceration is frequentlyencountered not only in sexually transmitted diseaseclinics but also in the primary care setting. The most commoncauses of painful ulcers are human herpesvirus 1 andhuman herpesvirus 2 infections; Haemophilus ducreyi infection,which causes chancroid; malignancy; drug-inducedulcer; and trauma. Painless ulcers are usually caused byT pallidum infection, granuloma inguinale, and lymphogranulomavenereum.Epidemiology. Coincident with the spread of AIDSin the 1980s and early 1990s, the incidence of syphilisincreased. Nearly 150,000 new cases are diagnosedeach year in the United States (16.8 cases per 100,000population); the incidence is higher in cities such asMiami, Atlanta, New York, and Washington,DC. The incidence is 9 timeshigher among African Americans andHispanics than among whites.Transmission. Infection is usuallyacquired by sexual contact, includingorogenital and anorectal; bykissing; or by close body contact.Congenital syphilis can be transmittedfrom an infected mother to theinfant. The incubation period variesfrom 1 to 13 weeks; 3 to 4 weeks istypical.Clinical features. The diseaseprogresses through primary, secondary,latent, and tertiary stages(Table 1). In the primary stage, the classic lesion is achancre that evolves and heals within 4 to 8 weeks inuntreated patients. After infection, a red papule usuallydevelops and quickly forms a painless, well-demarcated("punched out") ulcer that has an indurated base andexudes clear serous discharge (Table 2). Typically, theregional lymph nodes are enlarged, firm, rubbery, discrete,and nontender.Chancres can occur at different sites; the most commonare the penis, anus, and rectum in men and thevulva, cervix, and perineum in women. Chancres may alsooccur on the lips or the oropharyngeal area (Figure).Diagnosis. The classic presentation of a primarysyphilitic ulcer and the laboratory results establish the diagnosis.Darkfield examination of the serous fluid fromthe ulcer or aspirate from a regional lymph gland revealsa bright, motile, spiral organism that is 0.25 ?m wide and5 to 20 ?m long and has 8 to 12 curves.There are 2 classes of serologic tests for syphilis:

  • Nonspecific tests. VDRL and rapid plasma reagin (RPR)are nonspecific tests that may be negative initially. Thesetests may not become positive until 3 to 4 weeks afterexposure.
  • Specific treponemal tests. If the VDRL or RPR test is reactive,order a specific treponemal test, such as FTA-ABS,microhemagglutination assay to T pallidum (MHA-TP), orT pallidum hemagglutination assay (TPHA).


Once the diagnosis of primary syphilis isestablished, the drug of choice is IM penicillin, 2.4 millionunits (1.2 million units in each buttock) once. Alternativeregimens for patients who are allergic to penicillin areIV or IM ceftriaxone, 1 g/d for 3 days; oral doxycycline,200 mg bid for 15 days; or oral tetracycline, 500 mg q6hfor 15 days.


Plan follow-up visits and serologic (VDRLquantitative) testing at 1, 3, 6, and 12 months. The patientalso needs to be tested for HIV.Syphilis is a reportable disease. Sexual contacts mustbe traced (which is done by the public health department)and promptly treated.