Primary syphilis is the first stage of syphilis that occurs after infection with pale treponema and begins with skin manifestations at the site of its introduction. It is characterized by the appearance of a solid chancre (primary syphiloma) on the skin or mucosa, followed by the development of regional lymphangitis and lymphadenitis. When the elements of primary syphilis are localized on the skin of the penis, balanoposthitis, phimosis, gangrenization and other complications may develop. The diagnosis is established on the basis of anamnesis, the detection of solid chancre and the detection of pale treponemas in its discharge, positive results of serological studies, PCR diagnostics. Treatment is carried out with penicillin preparations.
Modern venereology notes some differences in the clinical pictur compared to those of its manifestations that were observed earlier. If earlier 90% of patients with primary syphilis had a solid chancre of a single character, now the number of cases of the appearance of 2 or more chancres at once has increased. There is a significant increase in ulcerative forms of solid chancre and forms complicated by pyoderma. The proportion of solid chancres located on the oral mucosa and in the anus has increased.
- Primary seropositive syphilis — accompanied by positive serological reactions to syphilis.
- Primary seronegative syphilis — serological studies in the patient give a negative result.
- Latent primary syphilis — occurs with the absence of clinical manifestations of the disease, can be seropositive and seronegative. This form of syphilis is more often observed in patients who started treatment at an early stage, but did not finish it.
Symptoms of primary syphilis
Clinical manifestations occur 10-90 days after infection of the patient. The place of appearance of the primary syphiloma, called a solid chancre, corresponds to the place of introduction of pale treponema through the skin or mucous membrane. As a rule, these are the genitals: in men, most often the head of the penis and the foreskin, in women — the labia, the mucous membrane of the vagina and cervix. Recently, with primary syphilis, extragenital (extra-sexual) location of the chancre is increasingly common: on the skin and mucous membrane of the anus, abdomen, thighs, pubis, fingers, lip mucosa, tongue and oral cavity.
The solid chancre of primary syphilis is a rounded fleshy-red erosion with a diameter of up to 1 cm. The raised edges of erosion give it a saucer-like appearance, and the scanty serous discharge makes its surface as if varnished. The solid chancre got its name due to the dense infiltration underlying the erosion. However, modern venereologists note in their practice cases of chancres without pronounced compaction at the base. Usually disease proceeds without subjective sensations, most patients note only minor soreness in the chancre area. The resolution of erosive chancre occurs without leaving any traces on the skin or mucous membrane. At the same time, with this disease, there are ulcerative forms of hard chancre with more pronounced edges and compaction of the base. Their healing occurs with the formation of a scar.
Disease can occur with the appearance of atypical forms of solid chancre, which is relatively rare. Atypical forms include: indurative edema, chancre-amygdalitis and chancre-panaritium. Indurative edema occurs in the scrotum, foreskin and labia majora. Its density is so great that pressing a finger in the place of edema does not leave a depression. Disease in the form of chancre-amygdalitis is manifested by unilateral painless enlargement and compaction of the amygdala, accompanied by its staining in red-copper color. The absence of pronounced inflammatory changes, soreness and temperature reaction makes it possible to distinguish this form of primary syphilis from angina or exacerbation of chronic tonsillitis.
Chancre-panaritium occurs most often with the development of primary syphilis in medical workers (gynecologists, urologists, dentists, laboratory assistants, etc.). It is characterized by sharp soreness, compaction and swelling of the terminal phalanx of one of the fingers of the hand. The absence of pronounced redness and the presence of dense infiltration of the affected area helps to assume primary syphilis in such cases. It is possible to suspect primary syphilis in all atypical forms of solid chancre by the pronounced increase in regional lymph nodes typical of syphilis: inguinal with indurative edema, cervical and submandibular with chancre-amygdalitis, ulnar with chancre-panaritia.
Most often, disease is complicated by secondary bacterial or trichomonas infection with the development of balanitis or balanoposthitis. The latter can lead to a narrowing of the foreskin with the appearance of phimosis. If, at the same time, a solid chancre is localized in the coronal furrow, then its examination becomes impossible, which makes it difficult to diagnose primary syphilis. Attempts by the patient to open the head independently can lead to its infringement and the occurrence of paraphimosis.
A more rare complication is gangrenization caused by fusospirillosis infection. In this case, the solid chancre is covered with a black scab. The spread of the process beyond the chancre indicates the development of phagedenism.
Not only a venereologist, but also an andrologist, urologist, gynecologist, dermatologist, otolaryngologist, proctologist, dentist faces the manifestations in their practice. The identification of a solid chancre and the presence in the patient’s history of information about sexual contact, which could be the cause of infection, is the main point at the initial stage of diagnosis of primary syphilis. Then a study of the separated chancre is carried out to detect pale treponema. An auxiliary method is the examination for pale treponema of a punctate taken during a lymph node biopsy. Serological reactions (RIF, RIBT, RPR test) become positive only after 3-4 weeks from the onset of manifestations of primary syphilis. Therefore, in the early period of primary syphilis, PCR diagnostics is used.
Differential diagnosis is carried out with genital herpes, trichomoniasis, gonorrhea, scabies, psoriasis, balanoposthitis, Keir’s disease, cervical erosion, vulvar cancer and other diseases. When a hard chancre is located on the lips, primary syphilis must be differentiated from cheilitis and herpes simplex, when it is localized on the oral mucosa — from stomatitis, pemphigus, ulcerative form of miliary tuberculosis, cancerous ulcers, mucosal lesions with lichen planus, systemic lupus erythematosus, leukoplakia.
Treatment of primary syphilis
Therapy of primary syphilis is carried out with penicillin-type drugs. Intramuscular administration of water-soluble penicillin is carried out every 3 hours, novocaine salt of benzylpenicillin twice a day or combined preparations of benzylpenicillin according to the scheme. The dose and duration of treatment depend on the form of primary syphilis. Examination and treatment of the patient’s sexual partners is important.
In patients with penicillin allergy, primary syphilis can be treated with doxycycline or tetracycline. Some studies indicate the effectiveness of ceftriaxone in the treatment of primary and secondary syphilis. However, a small number of such observations provides insufficient information to establish its optimal doses and the most appropriate duration of treatment.
After the treatment, patients with seronegative primary syphilis are under mandatory dispensary supervision for a year, and patients with seropositive primary syphilis — for three years. The control of cure is carried out throughout the entire period of dispensary observation by conducting an RPR test. Maintaining sharply positive test results for a year is an indication for additional treatment.