TY - CHAP M1 - Book, Section TI - SYPHILIS A1 - Lukehart, Sheila A. A2 - Kasper, Dennis L. A2 - Fauci, Anthony S. Y1 - 2017 N1 - T2 - Harrison's Infectious Diseases, 3e AB - Syphilis, a chronic systemic infection caused by Treponema pallidum subspecies pallidum, is usually sexually transmitted and is characterized by episodes of active disease interrupted by periods of latency. After an incubation period averaging 2–6 weeks, a primary lesion appears—often associated with regional lymphadenopathy—that resolves without treatment. The secondary stage, associated with generalized mucocutaneous lesions and generalized lymphadenopathy, is followed by a latent period of subclinical infection lasting years or decades. Central nervous system (CNS) involvement may occur early in infection and may be symptomatic or asymptomatic. In the preantibiotic era, about one-third of patients with untreated cases developed the tertiary stage, ­characterized by progressive destructive mucocutaneous, musculoskeletal, or parenchymal lesions; aortitis; or late CNS manifestations. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessbiomedicalscience.mhmedical.com/content.aspx?aid=1141409886 ER -