Seronegative Secondary Syphilis in 2 Patients Coinfected With Human Immunodeficiency Virus

Kingston et al detail two case reports on seronegative secondary syphilis in patients coinfected with human immudodefiency virus. Treponema pallidum is a fastidious organism that does not grow in routine laboratory cultures. Therefore, in immunocompetent patients, diagnosis of secondary syphilis relies largely on nontreponemal serologic tests such as the RPR or the Venereal Disease Research Laboratory that measure serum IgG and IgM antibody reactivity to a cardiolipin-cholesterol-lecithin antigen.