Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum. The signs and symptoms of syphilis vary depending in which of the four stages it presents (primary, (...)
Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum. The signs and symptoms of syphilis vary depending in which of the four stages it presents (primary, secondary, latent, and tertiary). The primary stage classically presents with a single chancre (a firm, painless, non-itchy skin ulceration) but there may be multiple sores. In secondary syphilis a diffuse rash occurs, which frequently involves the palms of the hands and soles of the feet. There may also be sores in the mouth or vagina. In latent syphilis, which can last for years, there are little to no symptoms. In tertiary syphilis there are gummas (soft non-cancerous growths), neurological, or heart symptoms.
Syphilis is difficult to diagnose clinically early in its presentation. Confirmation is either via blood tests or direct visual inspection using microscopy. Since direct microscopy is possible only when lesions are present, and this is not the case in the majority of patients, detection of antibodies against T. pallidum is the most effective method for the diagnosis of syphilis.
During early primary syphilis IgM class antibodies appear in the blood. In the secondary phase T. pallidum antibodies of both IgM and IgG classes reach peak titres and remain present in the blood at late stages of the disease. Successful treatment of syphilis in the primary phase shows a more rapid IgM decrease than in a late phase of the disease. A significant decrease in T. pallidum IgM titre can be expected within 3-4 months following successful treatment and will disappear usually within 2 years, merely depending on the assay in use. A decline in IgM levels can be used to monitor success of therapy.