Primary syphilis follows an incubation period of approximately 3 weeks and is characterized by a chancre, a painless, solitary lesion that originates at the site of inoculation, resolving spontaneously within 12 weeks regardless of treatment. The central nervous system (CNS) may be seeded with treponemes during this period, often in the absence of neurologic findings.
Secondary syphilis occurs 6–8 weeks later and is heralded by the appearance of lymphadenopathy and a generalized maculopapular rash that may be prominent on the palms and soles. Uveitis occurs in approximately 10% of cases. This phase is followed by a latent period ranging from 1 year (early latency) to decades (late latency).
Approximately one-third of untreated patients incur tertiary syphilis, which may be further subcategorized as benign tertiary syphilis (the characteristic lesion being gumma, most frequently found on the skin and mucous membranes but also in the choroid and iris), cardiovascular syphilis, and neurosyphilis. Although uveitis may occur in up to 5% of patients whose disease has progressed to tertiary syphilis, it can occur at any stage of infection, including primary disease. Because the eye is an extension of the CNS, ocular syphilis is best regarded as a variant of neurosyphilis, a notion that has important diagnostic and therapeutic implications.
Excerpted from BCSC 2020-2021 series: Section 9 - Uveitis and Ocular Inflammation. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.