Abstract

Secondary syphilis classically presents with a macular and/or papular rash of a pink to darkish red or copper or violaceous color. The rash is pathognomonically on the soles and palms, but can involve the trunk and whole extremities.1 Histologically, secondary syphilis most often presents with plasma cells. Necrotic keratinocytes are usually seen, as may be spirochetes at the dermal-epidermal junction.2 Here, we present a case of a pruritic, diffuse, pink to skin colored, nonscaly, papular rash covering the trunk, upper arms, face, and scalp that had been present for 4 months. The rash was biopsied on account of concern for papillary mucinosis. Hematoxylin and Eosin staining of 2 lesions from the upper back revealed diffuse naked granulomas in the upper dermis with a marked number of plasma cells. Warthin starry and Treponema pallidum immunohistochemical staining revealed numerous spirochetes. Lab testing was subsequently performed, revealing an RPR of 1:8192 and a reactive fluorescent treponemal ABS. This presents a unique case of secondary syphilis mimicking papular mucinosis clinically, and sarcoidosis histopathologically. There are few reports of similar cases in the literature that have similar features including diffuse papules with sparing of the palms and soles and noncaseating granulomas histopathologically3,4 1. Peeling RW, Mabey D, Kamb ML, Chen XS, Radolf JD, Benzaken AS. Syphilis. Nat Rev Dis Primers. 2017;3:17073. Published 2017 Oct 12. doi:10.1038/nrdp.2017.73 2. Liu XK, Li J. Histologic Features of Secondary Syphilis. Dermatology. 2020;236(2):145-150. 3. Rysgaard C, Alexander E, Swick BL. Nodular secondary syphilis with associated granulomatous inflammation: case report and literature review. J Cutan Pathol. 2014 Apr;41(4):370-9. doi: 10.1111/cup.12293. Epub 2014 Feb 13. 4. Breznik V, Poto?nik M, Miljkovi? J. Papulonodular secondary syphilis in a 52-year-old non-HIV heterosexual patient. Acta Dermatovenerol Alp Pannonica Adriat. 2010 Dec;19(4):27-30.

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