What Is Latent Syphilis?

Syphilis (syphilis) is a chronic infectious disease caused by Treponema pallidum (TP) and is mainly transmitted through sexual contact or blood. Those who have a history of syphilis infection, have no clinical symptoms or clinical symptoms have disappeared, have no positive signs except for syphilis serology, and those with normal cerebrospinal fluid examination are called latent syphilis (latent syphilis), which occurs compared with the body's immunity Strong or insufficient drug treatment doses are associated with temporary suppression of TP.

Basic Information

nickname

Recessive syphilis

English name

latent syphilis

Visiting department

dermatology

Common causes

Untreated syphilis or inadequate treatment doses, incomplete treatment

Causes of latent syphilis

The main cause of latent syphilis is that syphilis has not been treated or the dose of the treatment drug is insufficient, and the treatment is not thorough. Although the patient has no clinical symptoms, the syphilis has a positive seropositive response. Or the patient has a strong immune system, and has no or insignificant clinical symptoms (such as hard chancre of the cervix), and has no clinical manifestations since then. Only the syphilis serum test is positive, which are all latent syphilis. Its occurrence mainly depends on the patient's own immunity, the result of a contest between the therapeutic drug and Treponema pallidum. When the body's immune function is normal, or the drugs related to the treatment of syphilis are used irregularly, a certain therapeutic effect is produced. When the TP in the body is suppressed, it appears as latent syphilis, which can last for several months or the life of the infected person, 60% 70% of untreated patients can remain latent for as long as they are asymptomatic; when the body's health is poor and immune function is reduced, TP can take the opportunity to move in the human body and cause tissue damage to turn into dominant syphilis.

Clinical manifestations of latent syphilis

The stages of latent syphilis are exactly the same as those of dominant syphilis, which are divided into early and late stages. Infected within 2 years is called early latent syphilis, which is contagious, and those who are more than 2 years old are called late latent syphilis, which is weak or non-infectious (congenital latent syphilis is defined as 2 years old). Although latent syphilis does not have any clinical symptoms, it can be converted to dominant syphilis without treatment. Generally speaking, the clinical symptoms of primary syphilis are scleroderma and sclerosing lymphadenitis; the clinical symptoms of secondary syphilis are mainly skin and mucosal damage; in addition to skin and mucosal damage, tertiary syphilis can invade the bone, cardiovascular and nervous systems. Etc. cause severe system damage. Therefore, patients with syphilis should be followed up strictly on a regular basis to prevent latent syphilis.

Latent syphilis diagnosis

Latent syphilis can be judged based on the following conditions:

1. Syphilis serology test is positive, which is the main test method and diagnosis basis. It is divided into non-specific tests (including RPR, TRUST, and VDRL) and specific tests (including TPPA, TPHA, and FTA-ABS);

2. Whether there is a history of symptoms of one or two stages of syphilis; whether the sexual partner has a history of syphilis infection;

3. Cerebrospinal fluid examination is normal, exclude neurosyphilis;

4. X-ray film, color Doppler ultrasound, CT and MRI examinations are used for the auxiliary examination of bone and joint syphilis, cardiovascular syphilis and neurosyphilis.

5. Congenital latent syphilis is mainly diagnosed based on the history of syphilis in the mother of the child, combined with laboratory tests (positive TP or syphilis serum test).

Differential diagnosis of latent syphilis

Dominant early syphilis should be distinguished from soft chancre, genital herpes, fixed drug eruption, Behcet's disease, pityriasis rosea, and psoriasis. Tertiary syphilis should be identified from skin tuberculosis, leprosy, and skin tumors.

Latent Syphilis Treatment

1. Commonly used plum-driving drugs

(1) Penicillin is the drug of choice. Serum concentration of 0.03IU / ml has the effect of killing TP, but the serum concentration must be stably maintained for more than 10 days to completely remove TP from the body. Commonly used benzathine penicillin G, procaine water penicillin G, and water penicillin G. Cardiovascular syphilis does not use benzathine penicillin G.

(2) Ceftriaxone sodium has recently been confirmed to be a highly effective anti-TP drug, and it can be used as a preferred alternative treatment for penicillin allergies.

(3) Tetracycline and erythromycin are less effective than penicillin and are often used as an alternative treatment for penicillin allergies.

2. Choice of treatment plan

(1) Early syphilis benzathine penicillin G or procaine penicillin G. Those who are allergic to penicillin can choose ceftriaxone sodium or continuous oral tetracycline drugs, minocycline; or continuous oral erythromycin drugs (erythromycin).

(2) Late syphilis benzathine penicillin G or procaine penicillin G. People with penicillin allergy can use tetracycline or erythromycin for 30 days.

(3) Cardiovascular syphilis should be hospitalized. For those with concurrent heart failure, syphilis treatment should be performed after heart failure. First, the intramuscular injection of penicillin G was selected. On the fourth day, procaine penicillin G was intramuscularly injected for 15 consecutive days as a course of treatment, with a total of 2 courses of treatment, with an interval of 2 weeks. Treatment of penicillin allergies is the same as above.

(4) For neurosyphilis hospitalization, the intravenous infusion of penicillin G is preferred for 10 to 14 days, followed by benzathine penicillin G; or procaine penicillin G intramuscularly, and probenecid administered orally for 10 to 14 days. Followed by intramuscular injection of benzathine penicillin G once / week for 3 consecutive times. Treatment of penicillin allergies is the same as above.

(5) Pregnancy syphilis is treated according to the different stages of syphilis in pregnant women. The corresponding regimen is used for treatment and usage is the same as that of other syphilis patients in the same period, but one course of treatment is performed in the first 3 months and the last 3 months of pregnancy. Those who are allergic to penicillin use erythromycin drugs orally.

(6) Congenital syphilis Early congenital syphilis patients with abnormal cerebrospinal fluid should use the intravenous infusion of penicillin G for 10 to 14 consecutive days; or intramuscular injection of procaine penicillin G for 10 to 14 consecutive days. Those with normal cerebrospinal fluid used intramuscular injection of benzathine penicillin G. Those who checked the cerebrospinal fluid unconditionally were treated according to the scheme of those with abnormal cerebrospinal fluid. Intravenous injection of penicillin G2 for advanced congenital syphilis for 10 to 14 consecutive days; or intramuscular injection of procaine penicillin G for 10 to 14 consecutive days is a course of treatment, and 1 to 2 courses are available. The penicillin dose for older children should not exceed the adult patient dose for the same period. Those who are allergic to penicillin choose erythromycin and take it orally for 30 days.