Secondary and tertiary syphilis presenting as sarcoidal reactions of the skin.

Secondary and tertiary skin lesions of syphilis are infrequently biopsied and studied histologically. Examination of biopsy specimens from two patients, one with secondary and one with tertiary syphilis, revealed sarcoidal reactions, which caused confusion in the patients' diagnoses. The response to penicillin therapy in each patient was dramatic and contrary to the response anticipated in sarcoidosis. The histologic changes of secondary and tertiary syphilis are discussed.