Syphilis is a highly contagious venereal disease caused by syphilis spirochetes invading the body from the skin or mucous membrane at the site of sexual contact. If syphilis is not diagnosed and treated in time, syphilis spirochetes can enter the bloodstream from the skin and mucous membranes, invade the nerves, cardiovascular, bones and other tissues and organs, and cause serious damage to the body. Syphilis can also be transmitted to the next generation through the placenta if a pregnant woman has it. Early syphilis skin damage is not painful and itchy, syphilis rash in various forms, it is easy to confuse with other skin diseases, some early signs are often ignored and delayed treatment. Many patients write to us, hoping to understand the early manifestations of syphilis and the significance of the serologic test results for syphilis, here is a brief explanation of the issues of concern.
Syphilis spirochete diagram: 6-12μm long, 0.09-0.18μm wide, with 8-12 neat and uniform spirals.
The following cases occur, it is necessary to go to the hospital for examination to exclude syphilis.
1, with syphilis patients have had various ways of sexual contact (including sexual intercourse, oral sex, anal sex).
2. Painless hard nodes and ulcers in the genitals, mouth, anus, and rectum. They appear 2-4 weeks after impure sexual contact. This is the earliest skin damage of syphilis.
3. Dark red, rose or copper red scaly spots appear on the palms of the hands, soles of the feet or trunk and extremities without pain or itching.
4.Dark red or copper-red macules, ring-shaped rash or pustular rash without pain or itching appear on the trunk and extremities.
5.Scalp appears worm-like or patchy hair loss.
6, had unclean sexual contact experience, was diagnosed as “pityriasis rosea”, “folliculitis”, “parapsoriasis”, no obvious symptoms and long untreated.
7, genital, perianal flat warts (i.e.: set of red soft, flat papules, can proliferate and fuse into hypertrophic spots fast, the surface can have secretions, erosion).
8, no obvious reason for the mouth, tongue, pharynx appeared red, erosion.
9, suffering from other STDs such as genital herpes, condyloma acuminatum, gonorrhea patients, while the chances of contracting syphilis increased, should go to the hospital to investigate.
Interpretation of the significance of the syphilis serologic test
When syphilis infection is suspected, doctors often prescribe two tests, RPR and TPPA, which are important for confirming the diagnosis of syphilis and determining the prognosis.
(A) RPR test: Rapid plasma reactin test, is a non-syphilis spirochete antigen serologic test.
The test has high sensitivity but relatively low specificity. It is usually found 2-3 weeks after the appearance of the hard chancre, the earliest skin lesion of syphilis.
The RPR can sometimes be false positive for two reasons: (1) technical false positive: high antigen sensitivity, wrong serum specimen or hemolysis or bacterial contamination, unskilled examination room technique. ② biological false positive: because the antigen used in the non-spirochete test also exists in other tissues, so other diseases and even normal people can also appear. For syphilis it is called a false-positive reaction. Such as lupus erythematosus, autoimmune hemolytic anemia, rheumatoid arthritis, rheumatic heart disease, cirrhosis, polyarteritis nodosa, desiccation syndrome, measles, chickenpox, rubella, infectious mononucleosis, upper respiratory tract infection, scarlet fever, subacute bacterial endocarditis, pneumococcal pneumonia, active tuberculosis, malaria, etc. So only RPR positive can not be 100% conclusive syphilis, must also be positive TPPA to confirm the diagnosis.
3, early active syphilis RPR titer is elevated, after adequate treatment, RPR titer gradually decreases in 1 to 2 years, until it disappears. However, in some patients with early untreated syphilis that has progressed to advanced stages, RPR can also be reduced or disappear.
4.RPR test is suitable for population screening, efficacy observation and determination of recurrence or reinfection.
5, RPR serological fixation: some patients with early syphilis, not detected in time, or without standard treatment, or re-infection, although standardized treatment after diagnosis, but some patients RPR is always in low titer, does not turn negative, this phenomenon is called “early serological fixation”, because the disease has been cured, do not need repeated treatment. However, asymptomatic neurosyphilis and late syphilis (“late serological fixation”) should be excluded.
(ii) TPPA test :
1, syphilis spirochete passive particle agglutination test, is a syphilis spirochete antigen serologic test, this test has high sensitivity and specificity, and is generally used as a confirmatory test.
2, TPPA also occasionally has false positives, the incidence is less than RPR.
3.Even if the patient has been treated sufficiently, it can still exist for a long time, even for life, and the serologic reaction still persists positive, so this index has a confirmatory significance, but cannot be used to judge the efficacy.
4.If only positive TPPA is found, but negative RPR, there is no need to be nervous. Most of the cases belong to the previous syphilis, but has been cured.
Although syphilis is more harmful to humans, but as long as early detection, timely standardized treatment, regular review, can be cured.