Primary syphilis – clinical picture, differential diagnosis, treatment.
The first sign of syphilis is a small sore called a chancre. The sore appears at the spot where the bacteria entered your body. It usually develops about three weeks after exposure.
- Clinical features:
It appears as a single firm, painless, non-itchy skin ulceration with a clean base and sharp borders. They become painful after secondary infection. It heals spontaneously after 3 – 6 weeks.
The appearance of the genital and perianal chancre is followed by swelling of the inguinal lymph nodes, usually one side and then the other. The maxillary and submandibular lymph nodes enlarge when the infection is in the oral cavity.
Sites:
- In men, it usually occurs on the glans penis.
- In women, a chancre is less frequent, because the primary lesion may be on or in the cervix uteri. It can be found on the major or minor labia, on the clitoris and rarely on the vaginal wall.
- Extragenital changes may be found on the lips as a result of kissing or cummilingus (oral sex).
- In cases of homosexual activity, the arms and rectum are extragenital sites of infection.
- Differential diagnosis:
- Genital Herpes
- Secondarily infected traumatic sores
- Precancerous dermatoses
- On the lips: Herpes Simplex, traumatic ulcers, Behcet syndrome;
- Tonsillar chancres can be mistaken for tonsillitis.
- Treatment:
- Penicillin is the drug of choice for all stages of penicillin. So an injection of Benzathine penicillin G 2.4 MU i.m. single dose
- In case of penicillin allergy, 100mg of doxycycline twice daily x 14 days.
- 2mg of Azithromycin single oral dose.