Painless Ulcer on the Areola

The Diagnosis: Primary Syphilitic Chancre of the Nipple

Because laboratory investigation was negative, a primary syphilitic chancre was suspected based on clinical findings, which was confirmed by a positive rapid plasma reagin with a titer of 1:32 and a positive Treponema pallidum particle agglutination assay. Results were negative for human immunodeficiency virus. On further inquiry, the patient acknowledged that the right areola had been traumatized during sexual activity with his regular male partner 1 month prior. In the last year he reported having had 5 different male partners. He was treated with a single dose of 2.4 million IU of intramuscular benzathine penicillin. Screening for other sexually transmitted infections revealed concomitant gonococcal infection of the pharynx and chlamydia proctitis, both of which were subsequently treated. On follow-up 2 weeks after presentation the ulcer had resolved, and he currently is undergoing serial rapid plasma reagin titer monitoring.

Primary syphilitic chancres can occur at any mucocutaneous site of inoculation, most frequently on the genitalia. ¹ Classically, after an incubation period of 9 to 90 days, a painless indurated ulcer forms ² and heals spontaneously after 3 to 6 weeks if left untreated. ³ Chancres at extragenital sites are uncommon, occurring in approximately 2% of patients with primary syphilis .¹ Of them, common sites include the lips and mouth (40%-70%), ⁴ with areolar involvement rarely being reported. A PubMed search of articles indexed for MEDLINE using the terms nipple and chancre revealed 9 case reports in the English-language literature, with the first 2 cases being reported by Lee et al ⁵ in 2006. The characteristics of these cases and our patient are summarized in the Table. ^5-12

Oral contact or traumatization of the nipple by the patient's sexual partner was reported in all but one of these cases ^5-10,12; trauma was unknown in one case. ¹¹ Our patient reported a similar history of trauma to the nipple. It is known that transmission of syphilis can take place via kissing or oral contact, and it has been asserted that oral syphilitic lesions are highly infectious. ¹³ Syphilis also can be transmitted by an already infected sexual partner sustaining minor trauma at the oral mucosa, allowing Treponema pallidum from the bloodstream to be inoculated onto the nipple. Another explanation for transmission could be the Koebner phenomenon, whereby trauma at the nipple of an already infected patient could lead to the formation of a chancre. ^6,8

The differential diagnosis includes erosive adenomatosis of the nipple, nipple eczema, Paget disease of the breast, and ulcerated basal cell carcinoma. Erosive adenomatosis of the nipple is a benign tumor of unilateral involvement that presents as an asymptomatic eroded/ulcerated papule. Clinically, it is similar to Paget disease of the breast. Eczema of the nipple usually is associated with pruritus and epidermal changes such as scaling. ^7,8 Paget disease of the breast arises from the extension of breast ductal carcinoma in situ onto the skin overlying the nipple. It can present as a unilateral nipple plaque with ulceration and bloody discharge. The diagnoses of erosive adenomatosis and Paget disease are confirmed with histologic examination. Basal cell carcinoma is the most common nonmelanoma skin cancer and can present as an ulcerated plaque, often with rolled borders, pearly edges, and overlying telangiectasia. It is known to be locally invasive. A punch biopsy and histopathologic examination would confirm the diagnosis of basal cell carcinoma. ¹⁴

Extragenital chancres, especially those occurring at unusual sites, are uncommon. Therefore, a high index of suspicion is required to diagnose and initiate appropriate treatment for these patients.