Syphilis is a sexually transmitted infection which is systemic from the outset and has increased in incidence worldwide over the last decade. There has been concern as to whether or not co-infection with HIV can modify the clinical presentation of syphilis and, as a genital ulcer disease, it can facilitate the transmission of HIV infection. Diagnosis is based on the microscopic identification of the causative treponeme and serological testing.
Recommendations for the treatment of syphilis have been based on expert opinion, case series, some clinical trials and 50 years of clinical experience. Penicillin, given intramuscularly, is the mainstay of treatment and the favoured preparations for early infectious syphilis are benzathine penicillin as a single injection or a course of daily procaine penicillin injections for 10 to 14 days. The duration of treatment is longer for late syphilis. There has been concern that benzathine penicillin may not prevent the development of neurosyphilis but that is a rare outcome with this therapy. The main alternative to penicillin is doxycycline, but the place of azithromycin and ceftriaxone is yet to be established.
It is not necessary to carry out examination of the cerebrospinal fluid in patients with early infectious syphilis but it should be performed in those with neurological or ocular signs, psychiatric signs or symptoms, when there is evidence of treatment failure and in those who are co-infected with HIV.
Follow-up is an essential part of management and should be particularly assiduous, for at least 24 months, in those co-infected with HIV. Partner notification should be mandatory to try to contain the spread of infection.