The great imitator revisited: the spectrum of atypical cutaneous manifestations of secondary syphilis

Syphilis is a well‐known sexually transmitted infection infamous for its protean cutaneous manifestations. Over the last decade, the rate of infection in the USA has risen, particularly among human immunodeficiency virus (HIV)‐infected individuals and certain ethnic groups. Although the primary chancre developing at the site of inoculation usually has typical and well‐characterized features, cutaneous manifestations of secondary syphilis span a wide spectrum and mimic those of other dermatoses. This may be particularly evident in patients with HIV. Such deviations from the expected typical papulosquamous eruption may present a diagnostic challenge and delay diagnosis and therapy. Given the increasing incidence of syphilis among the immunosuppressed patient population, recognition of atypical cutaneous manifestations is critical for adequate management. We review a range of cutaneous manifestations of secondary syphilis and the skin diseases it may mimic.