A Case of Secondary Syphilis with the Extragenital Chancre o
Syphilis is a sexually transmitted disease caused by Treponema pallidum. The signs and symptoms of syphilis vary depending on which of the four stages it presents. The primary stage of syphilis classically presents with a painless ulcer (chancre). Authors report a case of the extragenital chancre on the nipple which is examined from skin biopsy and immunohistochemistry. This case showed that it is important to identify the special site's pruritus erythema by pathology and serological examination.

A 56-year-old male was presented to dermatology department with complaints of the right nipple erosion and discomfort for a week. Diagnosis of “eczema” was made and the patient was treated with topical zinc oxide oil and traditional Chinese herbal cream. Physical examination showed local erythematous erosion with a few exudations on the right nipple and a skin biopsy was performed. The histopathological results showed epidermal hyperplasia, cutaneous protrusion, migration of small amount of inflammatory cells, infiltration of large number of cells around the blood vessels of the dermis, and some of the nucleus were large, with scattered cells such as the lymphocytes and plasma cells.

Immunohistochemistry was recommended to confirm the diagnosis. The results revealed the (the right papillary skin) proliferation of lymphocytes: CD20(+), CD3(+), CD5(+), Pax-5(+), CD38(+), Bc1-2(+), CD10(?), Bcl-6(?), MUM1(?), Cyclin D1(?), CD163(+), Ig?(+), and Ig?(+), combined with hematoxylin-eosin (H-E) staining, showed numerous lymphoplasmacytes infiltration in the cutaneous dermal layer. On the follow-up, the patient complained of painless itchy erythema on bilateral soles. Physical examination showed that bilateral palms and soles had multiple copper-red macula and papules, some of which were desquamated on the surface.

The syphilis serology examination showed that TPPA was positive, RPR was positive, and the titer was more than 1?:?32, so the diagnosis was confirmed for syphilis. Then the patient was treated with IM injection of 2.4 million units of benzathine penicillin. Following a week later for follow up, the papillary erosion scab desquamation and the erythema subsided, the bilateral palms and the soles of dark erythema also subsided. And the 2.4 million units of benzathine penicillin were administered intramuscularly once a week for three weeks totally. The patient is still in further follow-up.

Source: https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC7036130/