In recent years, cases of syphilis have been increasing steadily since 2000. This infection is becoming increasingly common and, if left untreated, can lead to serious damage to the health of those who suffer from it.
Dr. Marta Herrero Romero, a specialist in infectious diseases, explains the general aspects of this infection, the types that exist and the treatments that can be applied.
Syphilis is a sexually transmitted infectious disease (including oral sex), which can also be transmitted via blood products and vertically, i.e. from mother to child.
The group most affected by this infection is men who have sex with men. This infection can be related to other sexually transmitted infections such as HIV.
What types of syphilis are there?
There are three types of syphilis:
- Primary syphilis: its incubation period can range from 14 days to 3 months, and frequently, it goes unnoticed without having any symptoms. It manifests itself through a cystic spot (erythematous papule) that usually transforms into a painless ulcer with a hard consistency. It may be a single papule or multiple papules may appear, especially in patients with HIV. The most common areas of appearance are on the hands, mouth, anus or genitals and are usually associated with regional lymphadenopathy, i.e. swollen lymph nodes. The physical lesions that appear, syphilitic chancres, are extremely contagious and usually resolve spontaneously after the first two months.
- Secondary syphilis: its incubation period varies from 6 weeks to 6 months. It is caused by the dissemination of Treponema pallidum from the initial lesion manifested in the patient. It is characterized by the appearance of a maculopapular skin infection, rounded red lesions generalized on the trunk, extremities, palms of the hands and soles of the feet. The oral mucosa may also be affected and ulcers may occur. This type of syphilis can produce biochemical meningitis with alterations in the cerebrospinal fluid (CSF) in 30% of patients, without developing neurosyphilis. If the CSF is affected, it can cause vascular and ocular alterations, mainly uveitis, and other manifestations such as fever, hepatitis, periostitis, arthritis or glomerulonephritis.
- Tertiary syphilis: it manifests after a latency period of 2 to 20 years. It is very rare nowadays. It is characterized by chronic inflammation at the systemic level, causing cardiovascular involvement such as aortic aneurysms and late neurosyphilis accompanied by confusion, hallucinations, cognitive alterations, among other symptoms.
What is the diagnosis of syphilis?
Syphilis is diagnosed by means of a luetic serology and its result will depend on the presence or absence of the clinical disease, on the history of having had syphilis in the past and on the patient’s immune response. A distinction can be made between:
- Treponemal tests: these are qualitative, more specific and earlier techniques to detect the presence or absence of the specific antibody directed against antigens: T. Pallidum. They are normally used for screening and do not serve to monitor treatment. They remain positive for life, without creating immunity, and reinfection is possible.
- Non-treponemal tests: these are tests that semi-quantitatively determine the presence of antibodies against non-specific antigens. They are not very specific and can cause false positives and can be negative in the presence of a symptomatic skin lesion (if it is very early, less than 3-4 weeks after infection). In addition, they may cross-react with chlamydia, HIV, the elderly, pregnant women or patients with autoimmune diseases.
What is the treatment?
The treatment for any type of syphilis is Penicillin to kill the organism that causes it. On the other hand, the dose to be administered will depend on the type of syphilis the patient suffers from. For primary, secondary and early latent syphilis (infection within the last year), a single dose of penicillin G benzathine 2.4 million IU intramuscular will be given; for late latent syphilis or syphilis of uncertain chronology, three doses spread over three weeks of penicillin G benzathine 2.4 million IU intramuscular will be given.