Quaternary Syphilis


Any condition indirectly due to syphilis.
The fourth chronologic stage of syphilis, which may follow tertiary syphilis in immunocompromised patients, e.g., those with AIDS, and is characterised by necrotising, spirochete-laden encephalitis, variably accompanied by evidence of end-stage HIV-1-induced anergy and/or loss of cell-mediated immunity against treponemal antigens